diff --git a/CLAUDE.md b/CLAUDE.md
index 10a3c368..b3a5b189 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -87,7 +87,7 @@ backend/src/main/java/org/raddatz/familienarchiv/
 ├── exception/           DomainException, ErrorCode, GlobalExceptionHandler
 ├── filestorage/         FileService (S3/MinIO)
 ├── geschichte/          Geschichte (story) domain
-├── importing/           MassImportService
+├── importing/           CanonicalImportOrchestrator + four loaders (TagTree/PersonRegister/PersonTree/Document) + CanonicalSheetReader
 ├── notification/        Notification domain + SseEmitterRegistry
 ├── ocr/                 OCR domain — OcrService, OcrBatchService, training
 ├── person/              Person domain
diff --git a/backend/CLAUDE.md b/backend/CLAUDE.md
index 249221cc..b96d242a 100644
--- a/backend/CLAUDE.md
+++ b/backend/CLAUDE.md
@@ -34,7 +34,7 @@ src/main/java/org/raddatz/familienarchiv/
 ├── exception/           # DomainException, ErrorCode, GlobalExceptionHandler
 ├── filestorage/         # FileService (S3/MinIO)
 ├── geschichte/          # Geschichte (story) domain
-├── importing/           # MassImportService
+├── importing/           # CanonicalImportOrchestrator + 4 loaders + CanonicalSheetReader
 ├── notification/        # Notification domain + SseEmitterRegistry
 ├── ocr/                 # OCR domain — OcrService, OcrBatchService, training
 ├── person/              # Person domain — Person, PersonService, PersonController
diff --git a/backend/src/main/java/org/raddatz/familienarchiv/exception/ErrorCode.java b/backend/src/main/java/org/raddatz/familienarchiv/exception/ErrorCode.java
index 54802f86..d9d0d8b2 100644
--- a/backend/src/main/java/org/raddatz/familienarchiv/exception/ErrorCode.java
+++ b/backend/src/main/java/org/raddatz/familienarchiv/exception/ErrorCode.java
@@ -40,6 +40,8 @@ public enum ErrorCode {
     // --- Import ---
     /** A mass import is already in progress; only one can run at a time. 409 */
     IMPORT_ALREADY_RUNNING,
+    /** A canonical import artifact is missing, unreadable, or missing a required header. 400 */
+    IMPORT_ARTIFACT_INVALID,
 
     // --- Thumbnails ---
     /** A thumbnail backfill is already in progress; only one can run at a time. 409 */
diff --git a/backend/src/main/java/org/raddatz/familienarchiv/importing/CanonicalImportOrchestrator.java b/backend/src/main/java/org/raddatz/familienarchiv/importing/CanonicalImportOrchestrator.java
new file mode 100644
index 00000000..2107bfda
--- /dev/null
+++ b/backend/src/main/java/org/raddatz/familienarchiv/importing/CanonicalImportOrchestrator.java
@@ -0,0 +1,94 @@
+package org.raddatz.familienarchiv.importing;
+
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+import org.raddatz.familienarchiv.exception.DomainException;
+import org.raddatz.familienarchiv.exception.ErrorCode;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.scheduling.annotation.Async;
+import org.springframework.stereotype.Service;
+
+import java.io.File;
+import java.time.LocalDateTime;
+import java.util.List;
+
+/**
+ * Runs the four canonical loaders in their real dependency order — encoded explicitly
+ * here, not implied by call order — and owns the async runner plus the {@link ImportStatus}
+ * state machine the admin UI consumes. The orchestrator smoke-checks that all four
+ * artifacts are present before starting, failing fast rather than half-loading tags but no
+ * documents. A malformed artifact (a loader throwing) sets {@code FAILED}; an individual
+ * bad file is surfaced through the {@link ImportStatus.SkippedFile} mechanism instead.
+ */
+@Service
+@RequiredArgsConstructor
+@Slf4j
+public class CanonicalImportOrchestrator {
+
+    private static final String TAG_TREE_ARTIFACT = "canonical-tag-tree.xlsx";
+    private static final String PERSONS_ARTIFACT = "canonical-persons.xlsx";
+    private static final String PERSONS_TREE_ARTIFACT = "canonical-persons-tree.json";
+    private static final String DOCUMENTS_ARTIFACT = "canonical-documents.xlsx";
+
+    private final TagTreeImporter tagTreeImporter;
+    private final PersonRegisterImporter personRegisterImporter;
+    private final PersonTreeImporter personTreeImporter;
+    private final DocumentImporter documentImporter;
+
+    @Value("${app.import.dir:/import}")
+    private String canonicalDir;
+
+    private volatile ImportStatus currentStatus = new ImportStatus(
+            ImportStatus.State.IDLE, "IMPORT_IDLE", "Kein Import gestartet.", 0, List.of(), null);
+
+    public ImportStatus getStatus() {
+        return currentStatus;
+    }
+
+    @Async
+    public void runImportAsync() {
+        if (currentStatus.state() == ImportStatus.State.RUNNING) {
+            throw DomainException.conflict(ErrorCode.IMPORT_ALREADY_RUNNING, "A mass import is already in progress");
+        }
+        runImport();
+    }
+
+    /** Synchronous entry point — wrapped by {@link #runImportAsync()} and called directly in tests. */
+    void runImport() {
+        currentStatus = new ImportStatus(ImportStatus.State.RUNNING, "IMPORT_RUNNING",
+                "Import läuft...", 0, List.of(), LocalDateTime.now());
+        try {
+            File tagTree = requireArtifact(TAG_TREE_ARTIFACT);
+            File persons = requireArtifact(PERSONS_ARTIFACT);
+            File personsTree = requireArtifact(PERSONS_TREE_ARTIFACT);
+            File documents = requireArtifact(DOCUMENTS_ARTIFACT);
+
+            // Dependency DAG: documents need persons + tags; the tree needs persons.
+            tagTreeImporter.load(tagTree);
+            personRegisterImporter.load(persons);
+            personTreeImporter.load(personsTree);
+            DocumentImporter.LoadResult result = documentImporter.load(documents);
+
+            currentStatus = new ImportStatus(ImportStatus.State.DONE, "IMPORT_DONE",
+                    "Import abgeschlossen. " + result.processed() + " Dokumente verarbeitet.",
+                    result.processed(), result.skippedFiles(), currentStatus.startedAt());
+        } catch (DomainException e) {
+            log.error("Canonical import failed: {}", e.getMessage());
+            currentStatus = new ImportStatus(ImportStatus.State.FAILED, "IMPORT_FAILED_ARTIFACT",
+                    "Fehler: " + e.getMessage(), 0, List.of(), currentStatus.startedAt());
+        } catch (Exception e) {
+            log.error("Canonical import failed", e);
+            currentStatus = new ImportStatus(ImportStatus.State.FAILED, "IMPORT_FAILED_INTERNAL",
+                    "Fehler: " + e.getMessage(), 0, List.of(), currentStatus.startedAt());
+        }
+    }
+
+    private File requireArtifact(String name) {
+        File artifact = new File(canonicalDir, name);
+        if (!artifact.isFile()) {
+            throw DomainException.badRequest(ErrorCode.IMPORT_ARTIFACT_INVALID,
+                    "Missing canonical artifact: " + name);
+        }
+        return artifact;
+    }
+}
diff --git a/backend/src/main/java/org/raddatz/familienarchiv/importing/CanonicalSheetReader.java b/backend/src/main/java/org/raddatz/familienarchiv/importing/CanonicalSheetReader.java
new file mode 100644
index 00000000..ece6a7ca
--- /dev/null
+++ b/backend/src/main/java/org/raddatz/familienarchiv/importing/CanonicalSheetReader.java
@@ -0,0 +1,133 @@
+package org.raddatz.familienarchiv.importing;
+
+import org.apache.poi.ss.usermodel.Cell;
+import org.apache.poi.ss.usermodel.DateUtil;
+import org.apache.poi.ss.usermodel.Sheet;
+import org.apache.poi.ss.usermodel.Workbook;
+import org.apache.poi.ss.usermodel.WorkbookFactory;
+import org.raddatz.familienarchiv.exception.DomainException;
+import org.raddatz.familienarchiv.exception.ErrorCode;
+
+import java.io.File;
+import java.io.FileInputStream;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+/**
+ * Value-level POI helper for the canonical import artifacts. No Spring, no domain
+ * knowledge: it opens a workbook, maps the header row to column indices by name, and
+ * yields typed rows whose cells are looked up by header name — the seam that replaces
+ * the old positional {@code @Value app.import.col.*} indices. List columns are split on
+ * the pipe delimiter the normalizer emits.
+ */
+public final class CanonicalSheetReader {
+
+    private CanonicalSheetReader() {
+    }
+
+    /** A single data row, addressable by canonical header name (never by index). */
+    public static final class Row {
+
+        private final Map<String, Integer> headerIndex;
+        private final List<String> cells;
+
+        private Row(Map<String, Integer> headerIndex, List<String> cells) {
+            this.headerIndex = headerIndex;
+            this.cells = cells;
+        }
+
+        /** Trimmed cell value for the named header, or "" when absent/blank. */
+        public String get(String header) {
+            Integer index = headerIndex.get(header);
+            if (index == null || index >= cells.size()) return "";
+            String value = cells.get(index);
+            return value == null ? "" : value.trim();
+        }
+    }
+
+    /**
+     * Reads all data rows from the first sheet, validating that every required header is
+     * present. Throws a fail-closed {@link DomainException} on a missing header so a
+     * loader never silently maps the wrong column.
+     */
+    public static List<Row> readRows(File file, List<String> requiredHeaders) {
+        try (FileInputStream fis = new FileInputStream(file);
+             Workbook workbook = WorkbookFactory.create(fis)) {
+
+            Sheet sheet = workbook.getSheetAt(0);
+            org.apache.poi.ss.usermodel.Row headerRow = sheet.getRow(sheet.getFirstRowNum());
+            Map<String, Integer> headerIndex = mapHeaders(headerRow);
+            requireHeaders(file, headerIndex, requiredHeaders);
+
+            List<Row> rows = new ArrayList<>();
+            for (int i = sheet.getFirstRowNum() + 1; i <= sheet.getLastRowNum(); i++) {
+                org.apache.poi.ss.usermodel.Row poiRow = sheet.getRow(i);
+                if (poiRow == null) continue;
+                rows.add(new Row(headerIndex, readCells(poiRow, headerIndex.size())));
+            }
+            return rows;
+        } catch (DomainException e) {
+            throw e;
+        } catch (Exception e) {
+            throw DomainException.badRequest(ErrorCode.IMPORT_ARTIFACT_INVALID,
+                    "Unreadable canonical artifact: " + file.getName());
+        }
+    }
+
+    /** Splits a pipe-delimited list column into trimmed, non-empty segments. */
+    public static List<String> splitList(String raw) {
+        if (raw == null || raw.isBlank()) return List.of();
+        return Arrays.stream(raw.split("\\|"))
+                .map(String::trim)
+                .filter(s -> !s.isEmpty())
+                .toList();
+    }
+
+    private static Map<String, Integer> mapHeaders(org.apache.poi.ss.usermodel.Row headerRow) {
+        if (headerRow == null) {
+            return Map.of();
+        }
+        Map<String, Integer> headerIndex = new HashMap<>();
+        for (int c = 0; c < headerRow.getLastCellNum(); c++) {
+            String name = cellToString(headerRow.getCell(c)).trim();
+            if (!name.isEmpty()) headerIndex.putIfAbsent(name, c);
+        }
+        return headerIndex;
+    }
+
+    private static void requireHeaders(File file, Map<String, Integer> headerIndex, List<String> requiredHeaders) {
+        for (String header : requiredHeaders) {
+            if (!headerIndex.containsKey(header)) {
+                throw DomainException.badRequest(ErrorCode.IMPORT_ARTIFACT_INVALID,
+                        "Missing required header '" + header + "' in artifact " + file.getName());
+            }
+        }
+    }
+
+    private static List<String> readCells(org.apache.poi.ss.usermodel.Row poiRow, int columnCount) {
+        int width = Math.max(columnCount, poiRow.getLastCellNum());
+        List<String> cells = new ArrayList<>(width);
+        for (int c = 0; c < width; c++) {
+            cells.add(cellToString(poiRow.getCell(c)));
+        }
+        return cells;
+    }
+
+    private static String cellToString(Cell cell) {
+        if (cell == null) return "";
+        return switch (cell.getCellType()) {
+            case STRING -> cell.getStringCellValue();
+            case NUMERIC -> {
+                if (DateUtil.isCellDateFormatted(cell)) {
+                    yield cell.getLocalDateTimeCellValue().toLocalDate().toString();
+                }
+                yield String.valueOf((long) cell.getNumericCellValue());
+            }
+            case BOOLEAN -> String.valueOf(cell.getBooleanCellValue());
+            default -> "";
+        };
+    }
+}
diff --git a/backend/src/main/java/org/raddatz/familienarchiv/importing/DocumentImporter.java b/backend/src/main/java/org/raddatz/familienarchiv/importing/DocumentImporter.java
new file mode 100644
index 00000000..6be566ab
--- /dev/null
+++ b/backend/src/main/java/org/raddatz/familienarchiv/importing/DocumentImporter.java
@@ -0,0 +1,334 @@
+package org.raddatz.familienarchiv.importing;
+
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+import org.raddatz.familienarchiv.document.DatePrecision;
+import org.raddatz.familienarchiv.document.Document;
+import org.raddatz.familienarchiv.document.DocumentService;
+import org.raddatz.familienarchiv.document.DocumentStatus;
+import org.raddatz.familienarchiv.document.ThumbnailAsyncRunner;
+import org.raddatz.familienarchiv.exception.DomainException;
+import org.raddatz.familienarchiv.exception.ErrorCode;
+import org.raddatz.familienarchiv.person.Person;
+import org.raddatz.familienarchiv.person.PersonService;
+import org.raddatz.familienarchiv.person.PersonType;
+import org.raddatz.familienarchiv.person.PersonUpsertCommand;
+import org.raddatz.familienarchiv.tag.Tag;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.stereotype.Component;
+import org.springframework.transaction.annotation.Transactional;
+import software.amazon.awssdk.core.sync.RequestBody;
+import software.amazon.awssdk.services.s3.S3Client;
+import software.amazon.awssdk.services.s3.model.PutObjectRequest;
+
+import org.raddatz.familienarchiv.tag.TagService;
+
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.time.LocalDate;
+import java.time.format.DateTimeParseException;
+import java.util.ArrayList;
+import java.util.LinkedHashSet;
+import java.util.List;
+import java.util.Optional;
+import java.util.Set;
+import java.util.UUID;
+import java.util.stream.Stream;
+
+/**
+ * Loads {@code canonical-documents.xlsx} into the document domain. Java performs no
+ * semantic transformation: the normalizer already resolved people to slugs and dates to
+ * ISO values. This loader maps columns by header name, routes each attribution
+ * register-first (always retaining the raw cell in {@code sender_text}/{@code receiver_text}),
+ * parses clean dates, and keeps the file/S3/thumbnail plumbing.
+ *
+ * <p>The {@code file} value is hostile input regardless of upstream trust (CWE-22 does not
+ * care that it came from our Python tool): its basename is validated with
+ * {@link #isValidImportFilename} and then resolved with canonical-path containment in
+ * {@link #findFileRecursive}.
+ */
+@Component
+@RequiredArgsConstructor
+@Slf4j
+public class DocumentImporter {
+
+    static final List<String> REQUIRED_HEADERS = List.of(
+            "index", "file", "sender_person_id", "sender_name",
+            "receiver_person_ids", "receiver_names", "date_iso", "date_raw", "date_precision");
+
+    private final DocumentService documentService;
+    private final PersonService personService;
+    private final TagService tagService;
+    private final S3Client s3Client;
+    private final ThumbnailAsyncRunner thumbnailAsyncRunner;
+
+    @Value("${app.s3.bucket:familienarchiv}")
+    private String bucketName;
+
+    @Value("${app.import.dir:/import}")
+    private String importDir;
+
+    /** Outcome of loading the document sheet: processed count + per-file skips. */
+    public record LoadResult(int processed, List<ImportStatus.SkippedFile> skippedFiles) {}
+
+    // One transaction for the whole sheet keeps the Hibernate session open so an existing
+    // document's lazy receivers collection initialises during an idempotent re-import.
+    // Invoked cross-bean from the orchestrator, so the @Transactional proxy applies.
+    @Transactional
+    public LoadResult load(File artifact) {
+        List<CanonicalSheetReader.Row> rows = CanonicalSheetReader.readRows(artifact, REQUIRED_HEADERS);
+        int processed = 0;
+        List<ImportStatus.SkippedFile> skipped = new ArrayList<>();
+        for (CanonicalSheetReader.Row row : rows) {
+            String index = row.get("index");
+            if (index.isBlank()) continue;
+            Optional<ImportStatus.SkipReason> skipReason = importRow(row, index, skipped);
+            if (skipReason.isPresent()) {
+                skipped.add(new ImportStatus.SkippedFile(displayName(row, index), skipReason.get()));
+            } else {
+                processed++;
+            }
+        }
+        log.info("Imported {} documents from {} ({} skipped)", processed, artifact.getName(), skipped.size());
+        return new LoadResult(processed, skipped);
+    }
+
+    private Optional<ImportStatus.SkipReason> importRow(CanonicalSheetReader.Row row, String index,
+                                                        List<ImportStatus.SkippedFile> skipped) {
+        Optional<File> resolved;
+        try {
+            resolved = resolveFile(row.get("file"));
+        } catch (InvalidImportFilenameException e) {
+            log.warn("Skipping import row {}: filename rejected", index);
+            return Optional.of(ImportStatus.SkipReason.INVALID_FILENAME_PATH_TRAVERSAL);
+        }
+        if (resolved.isPresent()) {
+            try {
+                if (!isPdfMagicBytes(resolved.get())) {
+                    return Optional.of(ImportStatus.SkipReason.INVALID_PDF_SIGNATURE);
+                }
+            } catch (IOException e) {
+                log.error("Magic-byte check failed for row {}", index, e);
+                return Optional.of(ImportStatus.SkipReason.FILE_READ_ERROR);
+            }
+        }
+        return persist(row, index, resolved);
+    }
+
+    private Optional<ImportStatus.SkipReason> persist(CanonicalSheetReader.Row row, String index, Optional<File> file) {
+        Document existing = documentService.findByOriginalFilename(index).orElse(null);
+        if (existing != null && existing.getStatus() != DocumentStatus.PLACEHOLDER) {
+            return Optional.of(ImportStatus.SkipReason.ALREADY_EXISTS);
+        }
+
+        String s3Key = null;
+        String contentType = null;
+        DocumentStatus status = DocumentStatus.PLACEHOLDER;
+        if (file.isPresent()) {
+            contentType = probeContentType(file.get());
+            s3Key = "documents/" + UUID.randomUUID() + "_" + file.get().getName();
+            try {
+                uploadToS3(file.get(), s3Key, contentType);
+                status = DocumentStatus.UPLOADED;
+            } catch (Exception e) {
+                log.error("S3 upload failed for {}", file.get().getName(), e);
+                return Optional.of(ImportStatus.SkipReason.S3_UPLOAD_FAILED);
+            }
+        }
+
+        Document doc = buildDocument(row, index, existing, s3Key, contentType, status);
+        Document saved = documentService.save(doc);
+        if (file.isPresent()) {
+            thumbnailAsyncRunner.dispatchAfterCommit(saved.getId());
+        }
+        return Optional.empty();
+    }
+
+    private Document buildDocument(CanonicalSheetReader.Row row, String index, Document existing,
+                                   String s3Key, String contentType, DocumentStatus status) {
+        Document doc = existing != null ? existing
+                : Document.builder().originalFilename(index).build();
+
+        String senderName = row.get("sender_name");
+        String receiverNames = row.get("receiver_names");
+        Person sender = resolveSender(row.get("sender_person_id"), senderName);
+        Set<Person> receivers = resolveReceivers(row.get("receiver_person_ids"));
+
+        doc.setTitle(index);
+        doc.setStatus(status);
+        doc.setFilePath(s3Key);
+        doc.setContentType(contentType);
+        doc.setSender(sender);
+        doc.setSenderText(blankToNull(senderName));
+        // The canonical row is authoritative for receivers/tags (ADR-025): clear then
+        // re-populate so a shrunk set on re-import prunes stale links rather than
+        // accumulating them. The raw sender_text/receiver_text retention is separate.
+        doc.getReceivers().clear();
+        doc.getReceivers().addAll(receivers);
+        doc.setReceiverText(blankToNull(receiverNames));
+        doc.setDocumentDate(parseIsoDate(row.get("date_iso")));
+        doc.setMetaDatePrecision(parsePrecision(row.get("date_precision")));
+        doc.setMetaDateEnd(parseIsoDate(row.get("date_end")));
+        doc.setMetaDateRaw(blankToNull(row.get("date_raw")));
+        doc.setLocation(blankToNull(row.get("location")));
+        doc.setSummary(blankToNull(row.get("summary")));
+        attachTag(doc, row.get("tags"));
+        doc.setMetadataComplete(doc.getDocumentDate() != null || sender != null || !receivers.isEmpty());
+        return doc;
+    }
+
+    // ─── attribution routing — register-first, always retain raw ─────────────────────
+
+    private Person resolveSender(String slug, String rawName) {
+        if (slug.isBlank()) return null;
+        return resolvePerson(slug, rawName);
+    }
+
+    private Set<Person> resolveReceivers(String slugs) {
+        Set<Person> receivers = new LinkedHashSet<>();
+        for (String slug : CanonicalSheetReader.splitList(slugs)) {
+            receivers.add(resolvePerson(slug, slug));
+        }
+        return receivers;
+    }
+
+    private Person resolvePerson(String slug, String rawName) {
+        return personService.findBySourceRef(slug)
+                .orElseGet(() -> personService.upsertBySourceRef(PersonUpsertCommand.builder()
+                        .sourceRef(slug)
+                        .lastName(blankToNull(rawName) == null ? slug : rawName)
+                        .personType(PersonType.PERSON)
+                        .provisional(true)
+                        .build()));
+    }
+
+    // Authoritative: the canonical row defines the document's tags exactly. Clearing first
+    // means a tag removed from the row is pruned on re-import (ADR-025).
+    private void attachTag(Document doc, String tagPath) {
+        doc.getTags().clear();
+        if (tagPath.isBlank()) return;
+        tagService.findBySourceRef(tagPath).ifPresent(tag -> doc.getTags().add(tag));
+    }
+
+    // ─── clean-value parsing (no semantic logic) ─────────────────────────────────────
+
+    private static LocalDate parseIsoDate(String value) {
+        if (value == null || value.isBlank()) return null;
+        try {
+            return LocalDate.parse(value.trim());
+        } catch (DateTimeParseException e) {
+            return null;
+        }
+    }
+
+    private static DatePrecision parsePrecision(String value) {
+        if (value == null || value.isBlank()) return DatePrecision.UNKNOWN;
+        try {
+            return DatePrecision.valueOf(value.trim());
+        } catch (IllegalArgumentException e) {
+            return DatePrecision.UNKNOWN;
+        }
+    }
+
+    // ─── file handling + S3 (small ≤20-line methods) ─────────────────────────────────
+
+    private Optional<File> resolveFile(String fileColumn) {
+        if (fileColumn == null || fileColumn.isBlank()) return Optional.empty();
+        String basename = basenameOf(fileColumn);
+        if (!isValidImportFilename(basename)) {
+            throw new InvalidImportFilenameException();
+        }
+        return findFileRecursive(basename);
+    }
+
+    private static String basenameOf(String fileColumn) {
+        String normalized = fileColumn.replace('\\', '/');
+        int lastSlash = normalized.lastIndexOf('/');
+        return lastSlash < 0 ? normalized.trim() : normalized.substring(lastSlash + 1).trim();
+    }
+
+    private String probeContentType(File file) {
+        try {
+            String probed = Files.probeContentType(file.toPath());
+            return probed != null ? probed : "application/octet-stream";
+        } catch (IOException e) {
+            return "application/octet-stream";
+        }
+    }
+
+    private void uploadToS3(File file, String s3Key, String contentType) {
+        s3Client.putObject(PutObjectRequest.builder()
+                        .bucket(bucketName)
+                        .key(s3Key)
+                        .contentType(contentType)
+                        .build(),
+                RequestBody.fromFile(file));
+    }
+
+    // ─── security guards — ported verbatim from MassImportService — do not weaken ────
+
+    private boolean isValidImportFilename(String filename) {
+        if (filename == null || filename.isBlank()) return false;
+        if (filename.contains("/")) return false;
+        if (filename.contains("\\")) return false;
+        if (filename.contains("∕")) return false;  // U+2215 DIVISION SLASH
+        if (filename.contains("／")) return false;  // U+FF0F FULLWIDTH SOLIDUS
+        if (filename.contains("⧵")) return false;  // U+29F5 REVERSE SOLIDUS OPERATOR
+        if (filename.contains("..")) return false;
+        if (filename.equals(".")) return false;
+        if (filename.contains("\0")) return false;
+        if (Paths.get(filename).isAbsolute()) return false;
+        return true;
+    }
+
+    // package-private: a Mockito spy in tests can override to inject IOException
+    InputStream openFileStream(File file) throws IOException {
+        return new FileInputStream(file);
+    }
+
+    private boolean isPdfMagicBytes(File file) throws IOException {
+        try (InputStream is = openFileStream(file)) {
+            byte[] header = is.readNBytes(4);
+            return header.length == 4
+                    && header[0] == 0x25  // %
+                    && header[1] == 0x50  // P
+                    && header[2] == 0x44  // D
+                    && header[3] == 0x46; // F
+        }
+    }
+
+    private Optional<File> findFileRecursive(String filename) {
+        File baseDir = new File(importDir);
+        try (Stream<Path> walk = Files.walk(baseDir.toPath())) {
+            Optional<Path> match = walk.filter(p -> !Files.isDirectory(p))
+                    .filter(p -> p.getFileName().toString().equals(filename))
+                    .findFirst();
+            if (match.isEmpty()) return Optional.empty();
+            File candidate = match.get().toFile();
+            String baseDirCanonical = baseDir.getCanonicalPath();
+            if (!candidate.getCanonicalPath().startsWith(baseDirCanonical + File.separator)) {
+                throw DomainException.internal(ErrorCode.INTERNAL_ERROR, "Path escape detected: " + candidate);
+            }
+            return Optional.of(candidate);
+        } catch (IOException e) {
+            return Optional.empty();
+        }
+    }
+
+    private static String displayName(CanonicalSheetReader.Row row, String index) {
+        String file = row.get("file");
+        return file.isBlank() ? index : basenameOf(file);
+    }
+
+    private static String blankToNull(String s) {
+        return (s == null || s.isBlank()) ? null : s;
+    }
+
+    private static final class InvalidImportFilenameException extends RuntimeException {
+    }
+}
diff --git a/backend/src/main/java/org/raddatz/familienarchiv/importing/ImportStatus.java b/backend/src/main/java/org/raddatz/familienarchiv/importing/ImportStatus.java
new file mode 100644
index 00000000..ae21adc2
--- /dev/null
+++ b/backend/src/main/java/org/raddatz/familienarchiv/importing/ImportStatus.java
@@ -0,0 +1,50 @@
+package org.raddatz.familienarchiv.importing;
+
+import com.fasterxml.jackson.annotation.JsonIgnore;
+import com.fasterxml.jackson.annotation.JsonProperty;
+import io.swagger.v3.oas.annotations.media.Schema;
+
+import java.time.LocalDateTime;
+import java.util.List;
+
+/**
+ * Async import state surfaced to {@code admin/system/ImportStatusCard.svelte} via the
+ * generated types. The shape ({@code state, statusCode, processed, skippedFiles, skipped})
+ * is kept verbatim from the retired MassImportService so the admin UI keeps working.
+ */
+public record ImportStatus(
+        @Schema(requiredMode = Schema.RequiredMode.REQUIRED) State state,
+        @Schema(requiredMode = Schema.RequiredMode.REQUIRED) String statusCode,
+        @JsonIgnore String message,
+        @Schema(requiredMode = Schema.RequiredMode.REQUIRED) int processed,
+        @Schema(requiredMode = Schema.RequiredMode.REQUIRED) List<SkippedFile> skippedFiles,
+        LocalDateTime startedAt
+) {
+
+    public enum State { IDLE, RUNNING, DONE, FAILED }
+
+    public enum SkipReason {
+        INVALID_FILENAME_PATH_TRAVERSAL,
+        INVALID_PDF_SIGNATURE,
+        FILE_READ_ERROR,
+        ALREADY_EXISTS,
+        S3_UPLOAD_FAILED
+    }
+
+    public record SkippedFile(
+            @Schema(requiredMode = Schema.RequiredMode.REQUIRED) String filename,
+            @Schema(requiredMode = Schema.RequiredMode.REQUIRED) SkipReason reason
+    ) {}
+
+    // Note: @Schema on a record accessor method is not picked up by SpringDoc; the
+    // "skipped" count is a computed convenience field derived from skippedFiles.size().
+    @JsonProperty("skipped")
+    public int skipped() {
+        return skippedFiles.size();
+    }
+
+    /** Defensive-copy constructor — callers cannot mutate the stored list after construction. */
+    public ImportStatus {
+        skippedFiles = List.copyOf(skippedFiles);
+    }
+}
diff --git a/backend/src/main/java/org/raddatz/familienarchiv/importing/MassImportService.java b/backend/src/main/java/org/raddatz/familienarchiv/importing/MassImportService.java
deleted file mode 100644
index 975517e7..00000000
--- a/backend/src/main/java/org/raddatz/familienarchiv/importing/MassImportService.java
+++ /dev/null
@@ -1,509 +0,0 @@
-package org.raddatz.familienarchiv.importing;
-
-import com.fasterxml.jackson.annotation.JsonIgnore;
-import com.fasterxml.jackson.annotation.JsonProperty;
-import io.swagger.v3.oas.annotations.media.Schema;
-import lombok.RequiredArgsConstructor;
-import lombok.extern.slf4j.Slf4j;
-import org.apache.poi.ss.usermodel.*;
-import java.util.Objects;
-import org.raddatz.familienarchiv.exception.DomainException;
-import org.raddatz.familienarchiv.exception.ErrorCode;
-import org.raddatz.familienarchiv.document.Document;
-import org.raddatz.familienarchiv.document.DocumentService;
-import org.raddatz.familienarchiv.document.DocumentStatus;
-import org.raddatz.familienarchiv.document.ThumbnailAsyncRunner;
-import org.raddatz.familienarchiv.person.Person;
-import org.raddatz.familienarchiv.tag.Tag;
-import org.raddatz.familienarchiv.person.Person;
-import org.raddatz.familienarchiv.person.PersonNameParser;
-import org.raddatz.familienarchiv.person.PersonService;
-import org.raddatz.familienarchiv.tag.TagService;
-import org.springframework.beans.factory.annotation.Value;
-import org.springframework.scheduling.annotation.Async;
-import org.springframework.stereotype.Service;
-import org.springframework.transaction.annotation.Transactional;
-import org.w3c.dom.Element;
-import org.w3c.dom.NodeList;
-import software.amazon.awssdk.core.sync.RequestBody;
-import software.amazon.awssdk.services.s3.S3Client;
-import software.amazon.awssdk.services.s3.model.PutObjectRequest;
-
-import javax.xml.parsers.DocumentBuilderFactory;
-import java.io.File;
-import java.io.FileInputStream;
-import java.io.IOException;
-import java.io.InputStream;
-import java.nio.file.Files;
-import java.nio.file.Path;
-import java.nio.file.Paths;
-import java.time.LocalDate;
-import java.time.LocalDateTime;
-import java.time.format.DateTimeFormatter;
-import java.time.format.DateTimeParseException;
-import java.util.ArrayList;
-import java.util.List;
-import java.util.Locale;
-import java.util.Optional;
-import java.util.UUID;
-import java.util.stream.Stream;
-import java.util.zip.ZipFile;
-
-@Service
-@RequiredArgsConstructor
-@Slf4j
-public class MassImportService {
-
-    public enum State { IDLE, RUNNING, DONE, FAILED }
-
-    public enum SkipReason {
-        INVALID_FILENAME_PATH_TRAVERSAL,
-        INVALID_PDF_SIGNATURE,
-        FILE_READ_ERROR,
-        ALREADY_EXISTS,
-        S3_UPLOAD_FAILED
-    }
-
-    public record SkippedFile(
-            @Schema(requiredMode = Schema.RequiredMode.REQUIRED) String filename,
-            @Schema(requiredMode = Schema.RequiredMode.REQUIRED) SkipReason reason
-    ) {}
-
-    public record ImportStatus(
-            @Schema(requiredMode = Schema.RequiredMode.REQUIRED) State state,
-            @Schema(requiredMode = Schema.RequiredMode.REQUIRED) String statusCode,
-            @JsonIgnore String message,
-            @Schema(requiredMode = Schema.RequiredMode.REQUIRED) int processed,
-            @Schema(requiredMode = Schema.RequiredMode.REQUIRED) List<SkippedFile> skippedFiles,
-            LocalDateTime startedAt
-    ) {
-        // Note: @Schema on a record accessor method is not picked up by SpringDoc; the
-        // "skipped" count is a computed convenience field derived from skippedFiles.size().
-        @JsonProperty("skipped")
-        public int skipped() { return skippedFiles.size(); }
-
-        /** Defensive-copy constructor — callers cannot mutate the stored list after construction. */
-        public ImportStatus {
-            skippedFiles = List.copyOf(skippedFiles);
-        }
-    }
-
-    record ProcessResult(int processed, List<SkippedFile> skippedFiles) {}
-
-    private volatile ImportStatus currentStatus = new ImportStatus(State.IDLE, "IMPORT_IDLE", "Kein Import gestartet.", 0, List.of(), null);
-
-    public ImportStatus getStatus() {
-        return currentStatus;
-    }
-
-    private final DocumentService documentService;
-    private final PersonService personService;
-    private final TagService tagService;
-    private final S3Client s3Client;
-    private final ThumbnailAsyncRunner thumbnailAsyncRunner;
-
-    @Value("${app.s3.bucket}")
-    private String bucketName;
-
-    @Value("${app.import.col.index:0}")
-    private int colIndex;
-
-    @Value("${app.import.col.box:1}")
-    private int colBox;
-
-    @Value("${app.import.col.folder:2}")
-    private int colFolder;
-
-    @Value("${app.import.col.sender:3}")
-    private int colSender;
-
-    @Value("${app.import.col.receivers:5}")
-    private int colReceivers;
-
-    @Value("${app.import.col.date:7}")
-    private int colDate;
-
-    @Value("${app.import.col.location:9}")
-    private int colLocation;
-
-    @Value("${app.import.col.tags:10}")
-    private int colTags;
-
-    @Value("${app.import.col.summary:11}")
-    private int colSummary;
-
-    @Value("${app.import.col.transcription:13}")
-    private int colTranscription;
-
-    @Value("${app.import.dir:/import}")
-    private String importDir;
-
-    private static final DateTimeFormatter GERMAN_DATE = DateTimeFormatter.ofPattern("d. MMMM yyyy", Locale.GERMAN);
-
-    // ODS XML namespaces
-    private static final String NS_TABLE = "urn:oasis:names:tc:opendocument:xmlns:table:1.0";
-    private static final String NS_TEXT  = "urn:oasis:names:tc:opendocument:xmlns:text:1.0";
-
-    // We only need up to this many columns; caps repeated-empty-cell expansion
-    private static final int MAX_COLS = 20;
-
-    @Async
-    public void runImportAsync() {
-        if (currentStatus.state() == State.RUNNING) {
-            throw DomainException.conflict(ErrorCode.IMPORT_ALREADY_RUNNING, "A mass import is already in progress");
-        }
-        currentStatus = new ImportStatus(State.RUNNING, "IMPORT_RUNNING", "Import läuft...", 0, List.of(), LocalDateTime.now());
-        try {
-            File spreadsheet = findSpreadsheetFile();
-            log.info("Starte Massenimport aus: {}", spreadsheet.getAbsolutePath());
-            ProcessResult result = processRows(readSpreadsheet(spreadsheet));
-            currentStatus = new ImportStatus(State.DONE, "IMPORT_DONE",
-                    "Import abgeschlossen. " + result.processed() + " Dokumente verarbeitet.",
-                    result.processed(), result.skippedFiles(), currentStatus.startedAt());
-        } catch (NoSpreadsheetException e) {
-            log.error("Massenimport fehlgeschlagen: keine Tabellendatei", e);
-            currentStatus = new ImportStatus(State.FAILED, "IMPORT_FAILED_NO_SPREADSHEET",
-                    "Fehler: " + e.getMessage(), 0, List.of(), currentStatus.startedAt());
-        } catch (Exception e) {
-            log.error("Massenimport fehlgeschlagen", e);
-            currentStatus = new ImportStatus(State.FAILED, "IMPORT_FAILED_INTERNAL",
-                    "Fehler: " + e.getMessage(), 0, List.of(), currentStatus.startedAt());
-        }
-    }
-
-    private static class NoSpreadsheetException extends RuntimeException {
-        NoSpreadsheetException(String message) { super(message); }
-    }
-
-    private File findSpreadsheetFile() throws IOException {
-        try (Stream<Path> files = Files.list(Paths.get(importDir))) {
-            return files
-                    .filter(p -> {
-                        String name = p.toString().toLowerCase();
-                        return name.endsWith(".ods") || name.endsWith(".xlsx") || name.endsWith(".xls");
-                    })
-                    .findFirst()
-                    .orElseThrow(() -> new NoSpreadsheetException(
-                            "Keine Tabellendatei (.ods/.xlsx/.xls) in " + importDir + " gefunden!"))
-                    .toFile();
-        }
-    }
-
-    // --- Spreadsheet reading (format-specific, produces neutral List<List<String>>) ---
-
-    private List<List<String>> readSpreadsheet(File file) throws Exception {
-        String name = file.getName().toLowerCase();
-        if (name.endsWith(".ods")) {
-            return readOds(file);
-        }
-        return readXlsx(file);
-    }
-
-    /**
-     * Reads an ODS file by parsing its content.xml directly (no extra library needed).
-     * ODS is a ZIP archive; content.xml holds the spreadsheet data as XML.
-     */
-    List<List<String>> readOds(File file) throws Exception {
-        List<List<String>> result = new ArrayList<>();
-
-        try (ZipFile zip = new ZipFile(file)) {
-            var entry = zip.getEntry("content.xml");
-            if (entry == null) throw new RuntimeException("Ungültige ODS-Datei: content.xml fehlt");
-
-            var factory = XxeSafeXmlParser.hardenedFactory();
-            factory.setNamespaceAware(true);
-            var builder = factory.newDocumentBuilder();
-            var doc = builder.parse(zip.getInputStream(entry));
-
-            NodeList tables = doc.getElementsByTagNameNS(NS_TABLE, "table");
-            if (tables.getLength() == 0) return result;
-
-            var table = (Element) tables.item(0);
-            NodeList rows = table.getElementsByTagNameNS(NS_TABLE, "table-row");
-
-            for (int i = 0; i < rows.getLength(); i++) {
-                var row = (Element) rows.item(i);
-                List<String> rowData = new ArrayList<>();
-                NodeList cells = row.getElementsByTagNameNS(NS_TABLE, "table-cell");
-
-                for (int j = 0; j < cells.getLength() && rowData.size() < MAX_COLS; j++) {
-                    var cell = (Element) cells.item(j);
-
-                    // Read the display text (first <text:p>)
-                    String value = "";
-                    NodeList textNodes = cell.getElementsByTagNameNS(NS_TEXT, "p");
-                    if (textNodes.getLength() > 0) {
-                        value = textNodes.item(0).getTextContent().trim();
-                    }
-
-                    // Expand number-columns-repeated (capped at MAX_COLS)
-                    String repeatAttr = cell.getAttributeNS(NS_TABLE, "number-columns-repeated");
-                    int repeat = repeatAttr.isEmpty() ? 1 : Integer.parseInt(repeatAttr);
-                    repeat = Math.min(repeat, MAX_COLS - rowData.size());
-
-                    for (int r = 0; r < repeat; r++) {
-                        rowData.add(value);
-                    }
-                }
-                result.add(rowData);
-            }
-        }
-        return result;
-    }
-
-    /** Reads an XLSX/XLS file using Apache POI. Converts all cells to strings. */
-    private List<List<String>> readXlsx(File file) throws Exception {
-        List<List<String>> result = new ArrayList<>();
-        try (FileInputStream fis = new FileInputStream(file);
-             Workbook workbook = WorkbookFactory.create(fis)) {
-
-            Sheet sheet = workbook.getSheetAt(0);
-            for (int i = 0; i <= sheet.getLastRowNum(); i++) {
-                Row row = sheet.getRow(i);
-                List<String> rowData = new ArrayList<>();
-                if (row != null) {
-                    for (int j = 0; j < MAX_COLS; j++) {
-                        rowData.add(xlsxCellToString(row.getCell(j)));
-                    }
-                }
-                result.add(rowData);
-            }
-        }
-        return result;
-    }
-
-    private String xlsxCellToString(Cell cell) {
-        if (cell == null) return "";
-        return switch (cell.getCellType()) {
-            case STRING -> cell.getStringCellValue();
-            case NUMERIC -> {
-                if (DateUtil.isCellDateFormatted(cell)) {
-                    yield cell.getLocalDateTimeCellValue().toLocalDate().toString(); // ISO
-                }
-                yield String.valueOf((int) cell.getNumericCellValue());
-            }
-            case BOOLEAN -> String.valueOf(cell.getBooleanCellValue());
-            default -> "";
-        };
-    }
-
-    // --- Import logic (works on neutral List<String> rows) ---
-
-    private ProcessResult processRows(List<List<String>> rows) {
-        int processed = 0;
-        List<SkippedFile> skippedFiles = new ArrayList<>();
-
-        for (int i = 1; i < rows.size(); i++) { // skip header row
-            List<String> cells = rows.get(i);
-            String index = getCell(cells, colIndex);
-            if (index.isBlank()) continue;
-
-            String filename = index.contains(".") ? index : index + ".pdf";
-            if (!isValidImportFilename(filename)) {
-                log.warn("Skipping import row {}: filename rejected — {}", i, filename);
-                skippedFiles.add(new SkippedFile(filename, SkipReason.INVALID_FILENAME_PATH_TRAVERSAL));
-                continue;
-            }
-            Optional<File> fileOnDisk = findFileRecursive(filename);
-            if (fileOnDisk.isEmpty()) {
-                log.warn("Datei nicht gefunden, importiere nur Metadaten: {}", filename);
-            }
-
-            if (fileOnDisk.isPresent()) {
-                try {
-                    if (!isPdfMagicBytes(fileOnDisk.get())) {
-                        log.warn("Überspringe {}: Datei beginnt nicht mit %PDF-Signatur", filename);
-                        skippedFiles.add(new SkippedFile(filename, SkipReason.INVALID_PDF_SIGNATURE));
-                        continue;
-                    }
-                } catch (IOException e) {
-                    log.error("Fehler beim Prüfen der Magic-Bytes für {}", filename, e);
-                    skippedFiles.add(new SkippedFile(filename, SkipReason.FILE_READ_ERROR));
-                    continue;
-                }
-            }
-
-            Optional<SkipReason> skipReason = importSingleDocument(cells, fileOnDisk, filename, index);
-            if (skipReason.isPresent()) {
-                skippedFiles.add(new SkippedFile(filename, skipReason.get()));
-            } else {
-                processed++;
-            }
-        }
-        return new ProcessResult(processed, skippedFiles);
-    }
-
-    private boolean isValidImportFilename(String filename) {
-        if (filename == null || filename.isBlank()) return false;
-        if (filename.contains("/")) return false;
-        if (filename.contains("\\")) return false;
-        if (filename.contains("∕")) return false;  // U+2215 DIVISION SLASH
-        if (filename.contains("／")) return false;  // U+FF0F FULLWIDTH SOLIDUS
-        if (filename.contains("⧵")) return false;  // U+29F5 REVERSE SOLIDUS OPERATOR
-        if (filename.contains("..")) return false;
-        if (filename.equals(".")) return false;
-        if (filename.contains("\0")) return false;
-        // Paths.get() is safe here on Linux for all inputs that passed the checks above;
-        // it may throw InvalidPathException for OS-specific illegal chars on Windows,
-        // but those are not reachable in production.
-        if (Paths.get(filename).isAbsolute()) return false;
-        return true;
-    }
-
-    // package-private: Mockito spy in tests can override to inject IOException
-    InputStream openFileStream(File file) throws IOException {
-        return new FileInputStream(file);
-    }
-
-    private boolean isPdfMagicBytes(File file) throws IOException {
-        try (InputStream is = openFileStream(file)) {
-            byte[] header = is.readNBytes(4);
-            return header.length == 4
-                    && header[0] == 0x25  // %
-                    && header[1] == 0x50  // P
-                    && header[2] == 0x44  // D
-                    && header[3] == 0x46; // F
-        }
-    }
-
-    /**
-     * Imports a single document row.
-     *
-     * @return empty Optional on success; an Optional containing the skip reason on failure/skip.
-     */
-    @Transactional
-    protected Optional<SkipReason> importSingleDocument(List<String> cells, Optional<File> file, String originalFilename, String index) {
-        Optional<Document> existing = documentService.findByOriginalFilename(originalFilename);
-        if (existing.isPresent() && existing.get().getStatus() != DocumentStatus.PLACEHOLDER) {
-            log.info("Dokument {} existiert bereits, überspringe.", originalFilename);
-            return Optional.of(SkipReason.ALREADY_EXISTS);
-        }
-
-        String archiveBox    = getCell(cells, colBox);
-        String archiveFolder = getCell(cells, colFolder);
-        String senderRaw     = getCell(cells, colSender);
-        String receiversRaw  = getCell(cells, colReceivers);
-        LocalDate date       = parseDate(getCell(cells, colDate));
-        String location      = getCell(cells, colLocation);
-        String tagRaw        = getCell(cells, colTags);
-        String summary       = getCell(cells, colSummary);
-        String transcription = getCell(cells, colTranscription);
-
-        String s3Key = null;
-        String contentType = null;
-        DocumentStatus status = DocumentStatus.PLACEHOLDER;
-
-        if (file.isPresent()) {
-            try {
-                contentType = Files.probeContentType(file.get().toPath());
-            } catch (IOException e) {
-                contentType = null;
-            }
-            if (contentType == null) contentType = "application/octet-stream";
-
-            s3Key = "documents/" + UUID.randomUUID() + "_" + file.get().getName();
-            try {
-                s3Client.putObject(PutObjectRequest.builder()
-                        .bucket(bucketName)
-                        .key(s3Key)
-                        .contentType(contentType)
-                        .build(),
-                        RequestBody.fromFile(file.get()));
-                status = DocumentStatus.UPLOADED;
-            } catch (Exception e) {
-                log.error("S3 Upload Fehler für {}", file.get().getName(), e);
-                return Optional.of(SkipReason.S3_UPLOAD_FAILED);
-            }
-        }
-
-        Person sender = senderRaw.isBlank() ? null : findOrCreatePerson(senderRaw);
-        List<Person> receivers = PersonNameParser.parseReceivers(receiversRaw).stream()
-                .map(this::findOrCreatePerson)
-                .filter(Objects::nonNull)
-                .toList();
-
-        Tag tag = null;
-        if (!tagRaw.isBlank()) {
-            tag = tagService.findOrCreate(tagRaw);
-        }
-
-        Document doc = existing.orElse(Document.builder()
-                .originalFilename(originalFilename)
-                .build());
-
-        // Heuristic: mark as complete if at least one key field is present in the spreadsheet row
-        boolean metadataComplete = date != null || !senderRaw.isBlank() || !receiversRaw.isBlank();
-
-        doc.setTitle(buildTitle(index, date, location));
-        doc.setFilePath(s3Key);
-        doc.setContentType(contentType);
-        doc.setStatus(status);
-        doc.setArchiveBox(archiveBox.isBlank() ? null : archiveBox);
-        doc.setArchiveFolder(archiveFolder.isBlank() ? null : archiveFolder);
-        doc.setDocumentDate(date);
-        doc.setLocation(location.isBlank() ? null : location);
-        doc.setSummary(summary.isBlank() ? null : summary);
-        doc.setTranscription(transcription.isBlank() ? null : transcription);
-        doc.setSender(sender);
-        doc.getReceivers().addAll(receivers);
-        if (tag != null) doc.getTags().add(tag);
-        doc.setMetadataComplete(metadataComplete);
-
-        Document saved = documentService.save(doc);
-        if (file.isPresent()) {
-            thumbnailAsyncRunner.dispatchAfterCommit(saved.getId());
-        }
-        log.info("Importiert{}: {}", file.isEmpty() ? " (nur Metadaten)" : "", originalFilename);
-        return Optional.empty();
-    }
-
-    // --- Helpers ---
-
-    private String getCell(List<String> cells, int col) {
-        if (col >= cells.size()) return "";
-        String val = cells.get(col);
-        return val == null ? "" : val.trim();
-    }
-
-    private LocalDate parseDate(String value) {
-        if (value == null || value.isBlank()) return null;
-        try {
-            return LocalDate.parse(value.trim());
-        } catch (DateTimeParseException e) {
-            return null;
-        }
-    }
-
-    private String buildTitle(String index, LocalDate date, String location) {
-        StringBuilder sb = new StringBuilder(index);
-        if (date != null) {
-            sb.append(" \u2013 ").append(date.format(GERMAN_DATE));
-        }
-        if (location != null && !location.isBlank()) {
-            sb.append(" \u2013 ").append(location);
-        }
-        return sb.toString();
-    }
-
-    private Person findOrCreatePerson(String rawName) {
-        return personService.findOrCreateByAlias(rawName);
-    }
-
-    private Optional<File> findFileRecursive(String filename) {
-        File baseDir = new File(importDir);
-        try (Stream<Path> walk = Files.walk(baseDir.toPath())) {
-            Optional<Path> match = walk.filter(p -> !Files.isDirectory(p))
-                    .filter(p -> p.getFileName().toString().equals(filename))
-                    .findFirst();
-            if (match.isEmpty()) return Optional.empty();
-            File candidate = match.get().toFile();
-            String baseDirCanonical = baseDir.getCanonicalPath();
-            if (!candidate.getCanonicalPath().startsWith(baseDirCanonical + File.separator)) {
-                throw DomainException.internal(ErrorCode.INTERNAL_ERROR, "Path escape detected: " + candidate);
-            }
-            return Optional.of(candidate);
-        } catch (IOException e) {
-            return Optional.empty();
-        }
-    }
-}
diff --git a/backend/src/main/java/org/raddatz/familienarchiv/importing/PersonRegisterImporter.java b/backend/src/main/java/org/raddatz/familienarchiv/importing/PersonRegisterImporter.java
new file mode 100644
index 00000000..edad55d2
--- /dev/null
+++ b/backend/src/main/java/org/raddatz/familienarchiv/importing/PersonRegisterImporter.java
@@ -0,0 +1,69 @@
+package org.raddatz.familienarchiv.importing;
+
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+import org.raddatz.familienarchiv.person.PersonService;
+import org.raddatz.familienarchiv.person.PersonType;
+import org.raddatz.familienarchiv.person.PersonUpsertCommand;
+import org.springframework.stereotype.Component;
+
+import java.io.File;
+import java.time.LocalDate;
+import java.time.format.DateTimeParseException;
+import java.util.List;
+
+/**
+ * Loads {@code canonical-persons.xlsx} (the register) into the person domain via
+ * {@link PersonService}, upserting each person by the normalizer {@code person_id}
+ * (source_ref). Register persons are confident identities, so {@code provisional} is
+ * driven by the sheet's already-clean value (normally {@code False}).
+ */
+@Component
+@RequiredArgsConstructor
+@Slf4j
+public class PersonRegisterImporter {
+
+    static final List<String> REQUIRED_HEADERS = List.of("person_id", "last_name", "first_name", "provisional");
+
+    private final PersonService personService;
+
+    public int load(File artifact) {
+        List<CanonicalSheetReader.Row> rows = CanonicalSheetReader.readRows(artifact, REQUIRED_HEADERS);
+        int processed = 0;
+        for (CanonicalSheetReader.Row row : rows) {
+            String personId = row.get("person_id");
+            if (personId.isBlank()) continue;
+            personService.upsertBySourceRef(toCommand(row, personId));
+            processed++;
+        }
+        log.info("Imported {} register persons from {}", processed, artifact.getName());
+        return processed;
+    }
+
+    private PersonUpsertCommand toCommand(CanonicalSheetReader.Row row, String personId) {
+        return PersonUpsertCommand.builder()
+                .sourceRef(personId)
+                .lastName(blankToNull(row.get("last_name")))
+                .firstName(blankToNull(row.get("first_name")))
+                .maidenName(blankToNull(row.get("maiden_name")))
+                .notes(blankToNull(row.get("notes")))
+                .birthYear(yearOf(row.get("birth_date")))
+                .deathYear(yearOf(row.get("death_date")))
+                .personType(PersonType.PERSON)
+                .provisional(Boolean.parseBoolean(row.get("provisional")))
+                .build();
+    }
+
+    private static Integer yearOf(String isoDate) {
+        if (isoDate == null || isoDate.isBlank()) return null;
+        try {
+            return LocalDate.parse(isoDate.trim()).getYear();
+        } catch (DateTimeParseException e) {
+            return null;
+        }
+    }
+
+    private static String blankToNull(String s) {
+        return (s == null || s.isBlank()) ? null : s;
+    }
+}
diff --git a/backend/src/main/java/org/raddatz/familienarchiv/importing/PersonTreeImporter.java b/backend/src/main/java/org/raddatz/familienarchiv/importing/PersonTreeImporter.java
new file mode 100644
index 00000000..26ae0dcd
--- /dev/null
+++ b/backend/src/main/java/org/raddatz/familienarchiv/importing/PersonTreeImporter.java
@@ -0,0 +1,135 @@
+package org.raddatz.familienarchiv.importing;
+
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+import org.raddatz.familienarchiv.exception.DomainException;
+import org.raddatz.familienarchiv.exception.ErrorCode;
+import org.raddatz.familienarchiv.person.Person;
+import org.raddatz.familienarchiv.person.PersonService;
+import org.raddatz.familienarchiv.person.PersonType;
+import org.raddatz.familienarchiv.person.PersonUpsertCommand;
+import org.raddatz.familienarchiv.person.relationship.RelationType;
+import org.raddatz.familienarchiv.person.relationship.RelationshipService;
+import org.raddatz.familienarchiv.person.relationship.dto.CreateRelationshipRequest;
+import org.springframework.stereotype.Component;
+
+import java.io.File;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.UUID;
+
+/**
+ * Loads {@code canonical-persons-tree.json} into the person + relationship domains.
+ * Tree persons are upserted via {@link PersonService} keyed on the shared
+ * {@code personId} slug (which Phase 1 #670 now emits into the tree), so they reconcile
+ * with the register rather than duplicating it. Relationships reference persons by the
+ * tree's local {@code rowId}; each side is mapped to the upserted person's UUID and
+ * created through {@link RelationshipService} (never the relationship repository —
+ * layering rule). A duplicate relationship on re-import is swallowed for idempotency.
+ */
+@Component
+@RequiredArgsConstructor
+@Slf4j
+public class PersonTreeImporter {
+
+    // The tree JSON is a local implementation detail, not a shared API payload, so the
+    // importer owns its own mapper rather than depending on the web ObjectMapper bean.
+    private static final ObjectMapper OBJECT_MAPPER = new ObjectMapper();
+
+    private final PersonService personService;
+    private final RelationshipService relationshipService;
+
+    public int load(File artifact) {
+        JsonNode root = readTree(artifact);
+        Map<String, UUID> idByRowId = upsertPersons(root.path("persons"));
+        int relationships = createRelationships(root.path("relationships"), idByRowId);
+        log.info("Imported {} tree persons and {} relationships from {}",
+                idByRowId.size(), relationships, artifact.getName());
+        return idByRowId.size();
+    }
+
+    private JsonNode readTree(File artifact) {
+        try {
+            return OBJECT_MAPPER.readTree(artifact);
+        } catch (Exception e) {
+            throw DomainException.badRequest(ErrorCode.IMPORT_ARTIFACT_INVALID,
+                    "Unreadable canonical artifact: " + artifact.getName());
+        }
+    }
+
+    private Map<String, UUID> upsertPersons(JsonNode persons) {
+        Map<String, UUID> idByRowId = new HashMap<>();
+        for (JsonNode node : persons) {
+            String personId = text(node, "personId");
+            if (personId.isBlank()) continue;
+            Person person = personService.upsertBySourceRef(toCommand(node, personId));
+            idByRowId.put(text(node, "rowId"), person.getId());
+        }
+        return idByRowId;
+    }
+
+    private PersonUpsertCommand toCommand(JsonNode node, String personId) {
+        return PersonUpsertCommand.builder()
+                .sourceRef(personId)
+                .lastName(blankToNull(text(node, "lastName")))
+                .firstName(blankToNull(text(node, "firstName")))
+                .maidenName(blankToNull(text(node, "maidenName")))
+                .notes(blankToNull(text(node, "notes")))
+                .birthYear(intOrNull(node, "birthYear"))
+                .deathYear(intOrNull(node, "deathYear"))
+                .familyMember(node.path("familyMember").asBoolean(false))
+                .personType(PersonType.PERSON)
+                .provisional(false)
+                .build();
+    }
+
+    private int createRelationships(JsonNode relationships, Map<String, UUID> idByRowId) {
+        int created = 0;
+        for (JsonNode node : relationships) {
+            // Trap: a relationship node's personId / relatedPersonId fields carry the tree's
+            // local rowId (e.g. "row_a"), NOT a person slug. They are resolved through
+            // idByRowId to the upserted person's UUID.
+            UUID person = idByRowId.get(text(node, "personId"));
+            UUID related = idByRowId.get(text(node, "relatedPersonId"));
+            if (person == null || related == null) {
+                log.warn("Skipping tree relationship with unresolved rowId: {} -> {}",
+                        text(node, "personId"), text(node, "relatedPersonId"));
+                continue;
+            }
+            if (addRelationshipIdempotently(person, related, text(node, "type"))) {
+                created++;
+            }
+        }
+        return created;
+    }
+
+    private boolean addRelationshipIdempotently(UUID person, UUID related, String type) {
+        try {
+            relationshipService.addRelationship(person,
+                    new CreateRelationshipRequest(related, RelationType.valueOf(type), null, null, null));
+            return true;
+        } catch (DomainException e) {
+            if (e.getCode() == ErrorCode.DUPLICATE_RELATIONSHIP
+                    || e.getCode() == ErrorCode.CIRCULAR_RELATIONSHIP) {
+                return false;
+            }
+            throw e;
+        }
+    }
+
+    private static String text(JsonNode node, String field) {
+        JsonNode value = node.get(field);
+        return value == null || value.isNull() ? "" : value.asText();
+    }
+
+    private static Integer intOrNull(JsonNode node, String field) {
+        JsonNode value = node.get(field);
+        return value == null || value.isNull() ? null : value.asInt();
+    }
+
+    private static String blankToNull(String s) {
+        return (s == null || s.isBlank()) ? null : s;
+    }
+}
diff --git a/backend/src/main/java/org/raddatz/familienarchiv/importing/TagTreeImporter.java b/backend/src/main/java/org/raddatz/familienarchiv/importing/TagTreeImporter.java
new file mode 100644
index 00000000..a871ab32
--- /dev/null
+++ b/backend/src/main/java/org/raddatz/familienarchiv/importing/TagTreeImporter.java
@@ -0,0 +1,54 @@
+package org.raddatz.familienarchiv.importing;
+
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+import org.raddatz.familienarchiv.tag.Tag;
+import org.raddatz.familienarchiv.tag.TagService;
+import org.springframework.stereotype.Component;
+
+import java.io.File;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.UUID;
+
+/**
+ * Loads {@code canonical-tag-tree.xlsx} into the tag domain via {@link TagService},
+ * upserting each tag by its canonical {@code tag_path} (the source_ref). Parent links are
+ * resolved by the parent's path, which is the child path with its last {@code /segment}
+ * stripped. Rows are emitted parents-first by the normalizer, so a parent is always
+ * resolved before any child references it.
+ */
+@Component
+@RequiredArgsConstructor
+@Slf4j
+public class TagTreeImporter {
+
+    static final List<String> REQUIRED_HEADERS = List.of("tag_path", "parent_name", "tag_name");
+    private static final String PATH_SEPARATOR = "/";
+
+    private final TagService tagService;
+
+    public int load(File artifact) {
+        List<CanonicalSheetReader.Row> rows = CanonicalSheetReader.readRows(artifact, REQUIRED_HEADERS);
+        Map<String, UUID> idByPath = new HashMap<>();
+        int processed = 0;
+        for (CanonicalSheetReader.Row row : rows) {
+            String path = row.get("tag_path");
+            if (path.isBlank()) continue;
+            UUID parentId = resolveParentId(path, idByPath);
+            Tag tag = tagService.upsertBySourceRef(path, row.get("tag_name"), parentId);
+            idByPath.put(path, tag.getId());
+            processed++;
+        }
+        log.info("Imported {} tags from {}", processed, artifact.getName());
+        return processed;
+    }
+
+    private UUID resolveParentId(String path, Map<String, UUID> idByPath) {
+        int lastSeparator = path.lastIndexOf(PATH_SEPARATOR);
+        if (lastSeparator < 0) return null;
+        String parentPath = path.substring(0, lastSeparator);
+        return idByPath.get(parentPath);
+    }
+}
diff --git a/backend/src/main/java/org/raddatz/familienarchiv/importing/XxeSafeXmlParser.java b/backend/src/main/java/org/raddatz/familienarchiv/importing/XxeSafeXmlParser.java
deleted file mode 100644
index 949ea054..00000000
--- a/backend/src/main/java/org/raddatz/familienarchiv/importing/XxeSafeXmlParser.java
+++ /dev/null
@@ -1,20 +0,0 @@
-package org.raddatz.familienarchiv.importing;
-
-import javax.xml.parsers.DocumentBuilderFactory;
-import javax.xml.parsers.ParserConfigurationException;
-
-class XxeSafeXmlParser {
-
-    private XxeSafeXmlParser() {}
-
-    static DocumentBuilderFactory hardenedFactory() throws ParserConfigurationException {
-        var factory = DocumentBuilderFactory.newInstance();
-        factory.setFeature("http://apache.org/xml/features/disallow-doctype-decl", true);
-        factory.setFeature("http://xml.org/sax/features/external-general-entities", false);
-        factory.setFeature("http://xml.org/sax/features/external-parameter-entities", false);
-        factory.setFeature("http://apache.org/xml/features/nonvalidating/load-external-dtd", false);
-        factory.setXIncludeAware(false);
-        factory.setExpandEntityReferences(false);
-        return factory;
-    }
-}
diff --git a/backend/src/main/java/org/raddatz/familienarchiv/person/PersonRepository.java b/backend/src/main/java/org/raddatz/familienarchiv/person/PersonRepository.java
index 1beebcc3..940e34a2 100644
--- a/backend/src/main/java/org/raddatz/familienarchiv/person/PersonRepository.java
+++ b/backend/src/main/java/org/raddatz/familienarchiv/person/PersonRepository.java
@@ -32,6 +32,9 @@ public interface PersonRepository extends JpaRepository<Person, UUID> {
     // Lookup by full alias string, used during ODS mass import
     Optional<Person> findByAliasIgnoreCase(String alias);
 
+    // Lookup by the normalizer person_id, used for idempotent canonical re-import (Phase 3).
+    Optional<Person> findBySourceRef(String sourceRef);
+
     // Exact first+last name match, used for filename-based sender lookup
     Optional<Person> findByFirstNameIgnoreCaseAndLastNameIgnoreCase(String firstName, String lastName);
 
diff --git a/backend/src/main/java/org/raddatz/familienarchiv/person/PersonService.java b/backend/src/main/java/org/raddatz/familienarchiv/person/PersonService.java
index 89b11ef3..d2e894bf 100644
--- a/backend/src/main/java/org/raddatz/familienarchiv/person/PersonService.java
+++ b/backend/src/main/java/org/raddatz/familienarchiv/person/PersonService.java
@@ -80,6 +80,11 @@ public class PersonService {
         return personRepository.findByFirstNameIgnoreCaseAndLastNameIgnoreCase(firstName, lastName);
     }
 
+    /** Lookup by the normalizer person_id — used by the canonical importer for register-first matching. */
+    public Optional<Person> findBySourceRef(String sourceRef) {
+        return personRepository.findBySourceRef(sourceRef);
+    }
+
     @Nullable
     @Transactional
     public Person findOrCreateByAlias(String rawName) {
@@ -115,6 +120,80 @@ public class PersonService {
         });
     }
 
+    /**
+     * Idempotent upsert keyed on {@code sourceRef} (the normalizer person_id) for the
+     * canonical importer (Phase 3, ADR-025). On first import the canonical fields are
+     * written verbatim. On re-import the human-edit-preserve precedence applies:
+     * a non-blank existing field is never overwritten, and {@code provisional} never
+     * flips back to true once a human has confirmed the person.
+     */
+    @Transactional
+    public Person upsertBySourceRef(PersonUpsertCommand cmd) {
+        return personRepository.findBySourceRef(cmd.sourceRef())
+                .map(existing -> personRepository.save(mergeCanonical(existing, cmd)))
+                .orElseGet(() -> fromCanonical(cmd));
+    }
+
+    private Person fromCanonical(PersonUpsertCommand cmd) {
+        Person person = personRepository.save(Person.builder()
+                .sourceRef(cmd.sourceRef())
+                .firstName(blankToNull(cmd.firstName()))
+                .lastName(cmd.lastName())
+                .notes(blankToNull(cmd.notes()))
+                .birthYear(cmd.birthYear())
+                .deathYear(cmd.deathYear())
+                .familyMember(cmd.familyMember())
+                .personType(cmd.personType() == null ? PersonType.PERSON : cmd.personType())
+                .provisional(cmd.provisional())
+                .build());
+        String maiden = blankToNull(cmd.maidenName());
+        if (maiden != null) {
+            int nextSortOrder = aliasRepository.findMaxSortOrder(person.getId()) + 1;
+            aliasRepository.save(PersonNameAlias.builder()
+                    .person(person)
+                    .lastName(maiden)
+                    .type(PersonNameAliasType.MAIDEN_NAME)
+                    .sortOrder(nextSortOrder)
+                    .build());
+        }
+        return person;
+    }
+
+    private Person mergeCanonical(Person existing, PersonUpsertCommand cmd) {
+        existing.setFirstName(preferHuman(existing.getFirstName(), cmd.firstName()));
+        existing.setLastName(preferHuman(existing.getLastName(), cmd.lastName()));
+        existing.setNotes(preferHuman(existing.getNotes(), cmd.notes()));
+        existing.setBirthYear(preferHuman(existing.getBirthYear(), cmd.birthYear()));
+        existing.setDeathYear(preferHuman(existing.getDeathYear(), cmd.deathYear()));
+        if (cmd.personType() != null && existing.getPersonType() == PersonType.PERSON) {
+            existing.setPersonType(cmd.personType());
+        }
+        // provisional is monotonic-downward: once it is false it never reverts to true.
+        // This also pins the cross-loader precedence (ADR-025): a register/tree person is
+        // loaded before documents and already false, so a later document row that references
+        // the same source_ref (provisional=true) can never flip it provisional — the guard
+        // below only fires while existing is still provisional. Order of document rows is
+        // therefore irrelevant.
+        if (existing.isProvisional()) {
+            existing.setProvisional(cmd.provisional());
+        }
+        return existing;
+    }
+
+    // preferHuman keeps an existing human-entered value and only falls back to the canonical
+    // value when the existing one is absent — the single idiom for every fill-blank field.
+    private static String preferHuman(String existing, String canonical) {
+        return (existing == null || existing.isBlank()) ? blankToNull(canonical) : existing;
+    }
+
+    private static Integer preferHuman(Integer existing, Integer canonical) {
+        return existing != null ? existing : canonical;
+    }
+
+    private static String blankToNull(String s) {
+        return (s == null || s.isBlank()) ? null : s.trim();
+    }
+
     @Transactional
     public Person createPerson(String firstName, String lastName, String alias) {
         Person person = Person.builder()
diff --git a/backend/src/main/java/org/raddatz/familienarchiv/person/PersonUpsertCommand.java b/backend/src/main/java/org/raddatz/familienarchiv/person/PersonUpsertCommand.java
new file mode 100644
index 00000000..63864ab6
--- /dev/null
+++ b/backend/src/main/java/org/raddatz/familienarchiv/person/PersonUpsertCommand.java
@@ -0,0 +1,24 @@
+package org.raddatz.familienarchiv.person;
+
+import lombok.Builder;
+
+/**
+ * Importer → {@link PersonService} command for an idempotent upsert keyed on
+ * {@code sourceRef} (the normalizer's stable person_id). Carries only the canonical
+ * fields the importer owns; the service applies the human-edit-preserve precedence
+ * (see ADR-025): non-blank existing fields are never overwritten, and {@code provisional}
+ * never flips back to true once a human has confirmed a person.
+ */
+@Builder
+public record PersonUpsertCommand(
+        String sourceRef,
+        String firstName,
+        String lastName,
+        String maidenName,
+        String notes,
+        Integer birthYear,
+        Integer deathYear,
+        boolean familyMember,
+        PersonType personType,
+        boolean provisional
+) {}
diff --git a/backend/src/main/java/org/raddatz/familienarchiv/tag/TagRepository.java b/backend/src/main/java/org/raddatz/familienarchiv/tag/TagRepository.java
index 4a7fab90..f1b3b7ab 100644
--- a/backend/src/main/java/org/raddatz/familienarchiv/tag/TagRepository.java
+++ b/backend/src/main/java/org/raddatz/familienarchiv/tag/TagRepository.java
@@ -22,6 +22,9 @@ public interface TagRepository extends JpaRepository<Tag, UUID> {
 
     Optional<Tag> findByNameIgnoreCase(String name);
 
+    // Lookup by the canonical tag_path, used for idempotent canonical re-import (Phase 3).
+    Optional<Tag> findBySourceRef(String sourceRef);
+
     List<Tag> findByNameContainingIgnoreCase(String name);
 
     /**
diff --git a/backend/src/main/java/org/raddatz/familienarchiv/tag/TagService.java b/backend/src/main/java/org/raddatz/familienarchiv/tag/TagService.java
index a572f84f..14e1e9fa 100644
--- a/backend/src/main/java/org/raddatz/familienarchiv/tag/TagService.java
+++ b/backend/src/main/java/org/raddatz/familienarchiv/tag/TagService.java
@@ -7,6 +7,7 @@ import java.util.HashSet;
 import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.Optional;
 import java.util.Set;
 import java.util.UUID;
 import java.util.stream.Collectors;
@@ -49,12 +50,37 @@ public class TagService {
                 .orElseThrow(() -> DomainException.notFound(ErrorCode.TAG_NOT_FOUND, "Tag not found: " + id));
     }
 
+    /** Lookup by the canonical tag_path — used by the canonical importer to attach a document's tag. */
+    public Optional<Tag> findBySourceRef(String sourceRef) {
+        return tagRepository.findBySourceRef(sourceRef);
+    }
+
     public Tag findOrCreate(String name) {
         String cleanName = name.trim();
         return tagRepository.findByNameIgnoreCase(cleanName)
                 .orElseGet(() -> tagRepository.save(Tag.builder().name(cleanName).build()));
     }
 
+    /**
+     * Idempotent upsert keyed on {@code sourceRef} (the canonical tag_path) for the
+     * Phase-3 importer (ADR-025). On first import the canonical name and parent are
+     * written; on re-import a human-renamed tag name is preserved (the source_ref is the
+     * stable identity, the name is a human-editable label).
+     */
+    @Transactional
+    public Tag upsertBySourceRef(String sourceRef, String name, UUID parentId) {
+        return tagRepository.findBySourceRef(sourceRef)
+                .map(existing -> {
+                    existing.setParentId(parentId);
+                    return tagRepository.save(existing);
+                })
+                .orElseGet(() -> tagRepository.save(Tag.builder()
+                        .sourceRef(sourceRef)
+                        .name(name)
+                        .parentId(parentId)
+                        .build()));
+    }
+
     @Transactional
     public Tag update(UUID id, TagUpdateDTO dto) {
         Tag tag = getById(id);
diff --git a/backend/src/main/java/org/raddatz/familienarchiv/user/AdminController.java b/backend/src/main/java/org/raddatz/familienarchiv/user/AdminController.java
index 18b6c2c0..74b5d643 100644
--- a/backend/src/main/java/org/raddatz/familienarchiv/user/AdminController.java
+++ b/backend/src/main/java/org/raddatz/familienarchiv/user/AdminController.java
@@ -5,7 +5,8 @@ import org.raddatz.familienarchiv.security.Permission;
 import org.raddatz.familienarchiv.security.RequirePermission;
 import org.raddatz.familienarchiv.document.DocumentService;
 import org.raddatz.familienarchiv.document.DocumentVersionService;
-import org.raddatz.familienarchiv.importing.MassImportService;
+import org.raddatz.familienarchiv.importing.CanonicalImportOrchestrator;
+import org.raddatz.familienarchiv.importing.ImportStatus;
 import org.raddatz.familienarchiv.document.ThumbnailBackfillService;
 import org.springframework.http.ResponseEntity;
 import org.springframework.web.bind.annotation.GetMapping;
@@ -21,20 +22,20 @@ import lombok.RequiredArgsConstructor;
 @RequiredArgsConstructor
 public class AdminController {
 
-    private final MassImportService massImportService;
+    private final CanonicalImportOrchestrator importOrchestrator;
     private final DocumentService documentService;
     private final DocumentVersionService documentVersionService;
     private final ThumbnailBackfillService thumbnailBackfillService;
 
     @PostMapping("/trigger-import")
-    public ResponseEntity<MassImportService.ImportStatus> triggerMassImport() {
-        massImportService.runImportAsync();
-        return ResponseEntity.accepted().body(massImportService.getStatus());
+    public ResponseEntity<ImportStatus> triggerMassImport() {
+        importOrchestrator.runImportAsync();
+        return ResponseEntity.accepted().body(importOrchestrator.getStatus());
     }
 
     @GetMapping("/import-status")
-    public ResponseEntity<MassImportService.ImportStatus> importStatus() {
-        return ResponseEntity.ok(massImportService.getStatus());
+    public ResponseEntity<ImportStatus> importStatus() {
+        return ResponseEntity.ok(importOrchestrator.getStatus());
     }
 
     @PostMapping("/backfill-versions")
diff --git a/backend/src/main/resources/application.yaml b/backend/src/main/resources/application.yaml
index e74f4d41..1e4558e0 100644
--- a/backend/src/main/resources/application.yaml
+++ b/backend/src/main/resources/application.yaml
@@ -125,17 +125,10 @@ app:
     password: ${APP_ADMIN_PASSWORD:admin123}
 
   import:
-    col:
-      index: 0
-      box: 1
-      folder: 2
-      sender: 3
-      receivers: 5
-      date: 7
-      location: 9
-      tags: 10
-      summary: 11
-      transcription: 13
+    # Directory holding the normalizer's committed canonical artifacts
+    # (canonical-{documents,persons,tag-tree}.xlsx + canonical-persons-tree.json).
+    # The loader maps columns by header name — no positional indices (see ADR-025).
+    dir: ${IMPORT_DIR:/import}
 
 ocr:
   sender-model:
diff --git a/backend/src/test/java/org/raddatz/familienarchiv/importing/CanonicalImportIntegrationTest.java b/backend/src/test/java/org/raddatz/familienarchiv/importing/CanonicalImportIntegrationTest.java
new file mode 100644
index 00000000..bd2b8d8f
--- /dev/null
+++ b/backend/src/test/java/org/raddatz/familienarchiv/importing/CanonicalImportIntegrationTest.java
@@ -0,0 +1,229 @@
+package org.raddatz.familienarchiv.importing;
+
+import org.apache.poi.ss.usermodel.Row;
+import org.apache.poi.ss.usermodel.Sheet;
+import org.apache.poi.xssf.usermodel.XSSFWorkbook;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.raddatz.familienarchiv.PostgresContainerConfig;
+import org.raddatz.familienarchiv.document.Document;
+import org.raddatz.familienarchiv.document.DocumentRepository;
+import org.raddatz.familienarchiv.document.DocumentStatus;
+import org.raddatz.familienarchiv.person.Person;
+import org.raddatz.familienarchiv.person.PersonRepository;
+import org.raddatz.familienarchiv.tag.TagRepository;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.context.annotation.Import;
+import org.springframework.test.context.ActiveProfiles;
+import org.springframework.test.context.bean.override.mockito.MockitoBean;
+import org.springframework.test.util.ReflectionTestUtils;
+import software.amazon.awssdk.services.s3.S3Client;
+
+import java.io.OutputStream;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.List;
+import java.util.Optional;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * Real Postgres (Testcontainers) integration test for the canonical importer. The
+ * {@code UNIQUE(source_ref)} constraint and the upsert-on-conflict behaviour only exist
+ * in real Postgres (never H2), so idempotency is verified here. S3 is mocked — the
+ * synthetic document rows carry no on-disk files, so every document is a PLACEHOLDER and
+ * no upload is attempted.
+ */
+@SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.NONE)
+@ActiveProfiles("test")
+@Import(PostgresContainerConfig.class)
+class CanonicalImportIntegrationTest {
+
+    @MockitoBean S3Client s3Client;
+
+    @Autowired CanonicalImportOrchestrator orchestrator;
+    @Autowired PersonRepository personRepository;
+    @Autowired TagRepository tagRepository;
+    @Autowired DocumentRepository documentRepository;
+
+    Path artifactDir;
+
+    @BeforeEach
+    void setUp() throws Exception {
+        documentRepository.deleteAll();
+        personRepository.deleteAll();
+        tagRepository.deleteAll();
+        artifactDir = Files.createTempDirectory("canonical-import-it");
+        writeArtifacts(artifactDir);
+        ReflectionTestUtils.setField(orchestrator, "canonicalDir", artifactDir.toString());
+    }
+
+    /**
+     * The import commits through its own transactions (the orchestrator is not transactional),
+     * so this test cannot rely on {@code @Transactional} rollback for isolation. Delete the
+     * committed rows after each test — otherwise the last test's documents (dated 1888-02) and
+     * persons/tags leak into the shared Testcontainers Postgres and pollute other integration
+     * tests that assume a known seed (e.g. DocumentDensityIntegrationTest,
+     * DocumentSearchPagedIntegrationTest). Mirrors the @AfterEach deleteAll convention used by
+     * DocumentListItemIntegrationTest.
+     */
+    @AfterEach
+    void cleanup() {
+        documentRepository.deleteAll();
+        personRepository.deleteAll();
+        tagRepository.deleteAll();
+    }
+
+    @Test
+    void reimport_isIdempotent_noDuplicatePersonsTagsOrDocuments() {
+        orchestrator.runImport();
+        long personsAfterFirst = personRepository.count();
+        long tagsAfterFirst = tagRepository.count();
+        long documentsAfterFirst = documentRepository.count();
+        assertThat(orchestrator.getStatus().state()).isEqualTo(ImportStatus.State.DONE);
+        assertThat(personsAfterFirst).isPositive();
+        assertThat(tagsAfterFirst).isPositive();
+        assertThat(documentsAfterFirst).isPositive();
+
+        orchestrator.runImport();
+
+        assertThat(personRepository.count()).isEqualTo(personsAfterFirst);
+        assertThat(tagRepository.count()).isEqualTo(tagsAfterFirst);
+        assertThat(documentRepository.count()).isEqualTo(documentsAfterFirst);
+    }
+
+    @Test
+    void reimport_preservesHumanEditedPersonField() {
+        orchestrator.runImport();
+        Person walter = personRepository.findBySourceRef("de-gruyter-walter").orElseThrow();
+        walter.setNotes("Verified by archivist");
+        walter.setFirstName("Walther");
+        personRepository.save(walter);
+
+        orchestrator.runImport();
+
+        Person reimported = personRepository.findBySourceRef("de-gruyter-walter").orElseThrow();
+        assertThat(reimported.getNotes()).isEqualTo("Verified by archivist");
+        assertThat(reimported.getFirstName()).isEqualTo("Walther");
+    }
+
+    @Test
+    void import_linksDocumentSenderToRegisterPerson_andRetainsRawText() {
+        orchestrator.runImport();
+
+        Person walter = personRepository.findBySourceRef("de-gruyter-walter").orElseThrow();
+        Document doc = documentRepository.findByOriginalFilename("W-0001").orElseThrow();
+        assertThat(doc.getSender()).isNotNull();
+        assertThat(doc.getSender().getId()).isEqualTo(walter.getId());
+        assertThat(doc.getSenderText()).isEqualTo("Walter de Gruyter");
+        assertThat(doc.getStatus()).isEqualTo(DocumentStatus.PLACEHOLDER);
+    }
+
+    @Test
+    void import_provisionalFlag_trueForImporterCreated_falseForRegister() {
+        orchestrator.runImport();
+
+        Optional<Person> register = personRepository.findBySourceRef("de-gruyter-walter");
+        assertThat(register).get().extracting(Person::isProvisional).isEqualTo(false);
+    }
+
+    @Test
+    void reimport_prunesRemovedReceiverAndTag_whenCanonicalRowShrinks() throws Exception {
+        orchestrator.runImport();
+        // findById uses the Document.full entity graph so receivers/tags initialise eagerly.
+        Document before = documentRepository.findById(
+                documentRepository.findByOriginalFilename("W-0001").orElseThrow().getId()).orElseThrow();
+        assertThat(before.getReceivers()).isNotEmpty();
+        assertThat(before.getTags()).isNotEmpty();
+
+        // Re-stage the document sheet with W-0001's receiver and tag removed.
+        writeSheet(artifactDir.resolve("canonical-documents.xlsx"),
+                List.of("index", "file", "sender_person_id", "sender_name", "receiver_person_ids",
+                        "receiver_names", "date_iso", "date_raw", "date_precision", "date_end", "location", "tags", "summary"),
+                List.of(
+                        List.of("W-0001", "", "de-gruyter-walter", "Walter de Gruyter",
+                                "", "", "1888-02-15", "15.2.1888", "DAY", "", "Rotterdam", "", "Geschäftsreise"),
+                        List.of("W-0002", "", "de-gruyter-eugenie", "Eugenie de Gruyter",
+                                "de-gruyter-walter", "Walter de Gruyter", "1888-02-16", "16.2.1888", "DAY", "",
+                                "Middelburg", "Themen/Brautbriefe", "Reisepläne")));
+
+        orchestrator.runImport();
+
+        Document after = documentRepository.findById(before.getId()).orElseThrow();
+        assertThat(after.getReceivers()).isEmpty();
+        assertThat(after.getTags()).isEmpty();
+    }
+
+    @Test
+    void import_neverFlipsRegisterPersonToProvisional_whenReferencedByDocumentRow() {
+        // de-gruyter-walter is a register person (provisional=false) AND the sender of W-0001.
+        // The orchestrator loads the register before documents, so the document loader's
+        // register-first match links the existing person and never mints a provisional one.
+        // A second run (documents reference the same person again) must not flip it true.
+        orchestrator.runImport();
+        orchestrator.runImport();
+
+        Person walter = personRepository.findBySourceRef("de-gruyter-walter").orElseThrow();
+        assertThat(walter.isProvisional()).isFalse();
+        Person eugenie = personRepository.findBySourceRef("de-gruyter-eugenie").orElseThrow();
+        assertThat(eugenie.isProvisional()).isFalse();
+    }
+
+    // ─── synthetic-but-real artifact set ─────────────────────────────────────────────
+
+    private void writeArtifacts(Path dir) throws Exception {
+        writeSheet(dir.resolve("canonical-tag-tree.xlsx"),
+                List.of("tag_path", "parent_name", "tag_name"),
+                List.of(
+                        List.of("Themen", "", "Themen"),
+                        List.of("Themen/Brautbriefe", "Themen", "Brautbriefe")));
+
+        writeSheet(dir.resolve("canonical-persons.xlsx"),
+                List.of("person_id", "last_name", "first_name", "maiden_name", "notes", "birth_date", "death_date", "provisional"),
+                List.of(
+                        List.of("de-gruyter-walter", "de Gruyter", "Walter", "", "", "1865-01-01", "", "False"),
+                        List.of("de-gruyter-eugenie", "de Gruyter", "Eugenie", "Wöhler", "", "", "", "False")));
+
+        Files.writeString(dir.resolve("canonical-persons-tree.json"), """
+                {"persons":[
+                  {"rowId":"row_1","firstName":"Walter","lastName":"de Gruyter","familyMember":true,"personId":"de-gruyter-walter"},
+                  {"rowId":"row_2","firstName":"Eugenie","lastName":"de Gruyter","maidenName":"Wöhler","familyMember":true,"personId":"de-gruyter-eugenie"}
+                ],"relationships":[
+                  {"personId":"row_1","relatedPersonId":"row_2","type":"SPOUSE_OF","source":"verheiratet_mit"}
+                ]}
+                """);
+
+        writeSheet(dir.resolve("canonical-documents.xlsx"),
+                List.of("index", "file", "sender_person_id", "sender_name", "receiver_person_ids",
+                        "receiver_names", "date_iso", "date_raw", "date_precision", "date_end", "location", "tags", "summary"),
+                List.of(
+                        List.of("W-0001", "", "de-gruyter-walter", "Walter de Gruyter",
+                                "de-gruyter-eugenie", "Eugenie de Gruyter", "1888-02-15", "15.2.1888", "DAY", "",
+                                "Rotterdam", "Themen/Brautbriefe", "Geschäftsreise"),
+                        List.of("W-0002", "", "de-gruyter-eugenie", "Eugenie de Gruyter",
+                                "de-gruyter-walter", "Walter de Gruyter", "1888-02-16", "16.2.1888", "DAY", "",
+                                "Middelburg", "Themen/Brautbriefe", "Reisepläne")));
+    }
+
+    private void writeSheet(Path file, List<String> headers, List<List<String>> rows) throws Exception {
+        try (XSSFWorkbook wb = new XSSFWorkbook()) {
+            Sheet sheet = wb.createSheet("Sheet1");
+            Row header = sheet.createRow(0);
+            for (int i = 0; i < headers.size(); i++) {
+                header.createCell(i).setCellValue(headers.get(i));
+            }
+            for (int r = 0; r < rows.size(); r++) {
+                Row row = sheet.createRow(r + 1);
+                List<String> values = rows.get(r);
+                for (int c = 0; c < values.size(); c++) {
+                    row.createCell(c).setCellValue(values.get(c));
+                }
+            }
+            try (OutputStream out = Files.newOutputStream(file)) {
+                wb.write(out);
+            }
+        }
+    }
+}
diff --git a/backend/src/test/java/org/raddatz/familienarchiv/importing/CanonicalImportOrchestratorTest.java b/backend/src/test/java/org/raddatz/familienarchiv/importing/CanonicalImportOrchestratorTest.java
new file mode 100644
index 00000000..dc12d070
--- /dev/null
+++ b/backend/src/test/java/org/raddatz/familienarchiv/importing/CanonicalImportOrchestratorTest.java
@@ -0,0 +1,130 @@
+package org.raddatz.familienarchiv.importing;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.junit.jupiter.api.io.TempDir;
+import org.mockito.InOrder;
+import org.mockito.Mock;
+import org.mockito.junit.jupiter.MockitoExtension;
+import org.raddatz.familienarchiv.exception.DomainException;
+import org.springframework.test.util.ReflectionTestUtils;
+
+import java.io.File;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.List;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.inOrder;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+@ExtendWith(MockitoExtension.class)
+class CanonicalImportOrchestratorTest {
+
+    @Mock TagTreeImporter tagTreeImporter;
+    @Mock PersonRegisterImporter personRegisterImporter;
+    @Mock PersonTreeImporter personTreeImporter;
+    @Mock DocumentImporter documentImporter;
+
+    private CanonicalImportOrchestrator orchestrator(Path dir) {
+        CanonicalImportOrchestrator o = new CanonicalImportOrchestrator(
+                tagTreeImporter, personRegisterImporter, personTreeImporter, documentImporter);
+        ReflectionTestUtils.setField(o, "canonicalDir", dir.toString());
+        return o;
+    }
+
+    private void writeAllArtifacts(Path dir) throws Exception {
+        Files.writeString(dir.resolve("canonical-tag-tree.xlsx"), "x");
+        Files.writeString(dir.resolve("canonical-persons.xlsx"), "x");
+        Files.writeString(dir.resolve("canonical-persons-tree.json"), "x");
+        Files.writeString(dir.resolve("canonical-documents.xlsx"), "x");
+    }
+
+    @Test
+    void getStatus_isIdleByDefault(@TempDir Path dir) {
+        assertThat(orchestrator(dir).getStatus().state()).isEqualTo(ImportStatus.State.IDLE);
+    }
+
+    @Test
+    void runImport_loadsTagsAndPersonsBeforeDocuments(@TempDir Path dir) throws Exception {
+        writeAllArtifacts(dir);
+        when(documentImporter.load(any())).thenReturn(new DocumentImporter.LoadResult(0, List.of()));
+        CanonicalImportOrchestrator o = orchestrator(dir);
+
+        o.runImport();
+
+        InOrder order = inOrder(tagTreeImporter, personRegisterImporter, personTreeImporter, documentImporter);
+        order.verify(tagTreeImporter).load(any());
+        order.verify(personRegisterImporter).load(any());
+        order.verify(personTreeImporter).load(any());
+        order.verify(documentImporter).load(any());
+    }
+
+    @Test
+    void runImport_setsStatusDone_onSuccess(@TempDir Path dir) throws Exception {
+        writeAllArtifacts(dir);
+        when(documentImporter.load(any())).thenReturn(new DocumentImporter.LoadResult(3, List.of()));
+        CanonicalImportOrchestrator o = orchestrator(dir);
+
+        o.runImport();
+
+        assertThat(o.getStatus().state()).isEqualTo(ImportStatus.State.DONE);
+        assertThat(o.getStatus().processed()).isEqualTo(3);
+    }
+
+    @Test
+    void runImport_failsClosed_whenAnArtifactIsMissing(@TempDir Path dir) throws Exception {
+        Files.writeString(dir.resolve("canonical-tag-tree.xlsx"), "x");
+        // the other three artifacts are absent
+        CanonicalImportOrchestrator o = orchestrator(dir);
+
+        o.runImport();
+
+        assertThat(o.getStatus().state()).isEqualTo(ImportStatus.State.FAILED);
+        verify(tagTreeImporter, never()).load(any());
+        verify(documentImporter, never()).load(any());
+    }
+
+    @Test
+    void runImport_setsStatusFailed_whenLoaderThrows(@TempDir Path dir) throws Exception {
+        writeAllArtifacts(dir);
+        when(tagTreeImporter.load(any())).thenThrow(DomainException.badRequest(
+                org.raddatz.familienarchiv.exception.ErrorCode.IMPORT_ARTIFACT_INVALID, "bad"));
+        CanonicalImportOrchestrator o = orchestrator(dir);
+
+        o.runImport();
+
+        assertThat(o.getStatus().state()).isEqualTo(ImportStatus.State.FAILED);
+        verify(documentImporter, never()).load(any());
+    }
+
+    @Test
+    void runImportAsync_throwsConflict_whenAlreadyRunning(@TempDir Path dir) {
+        CanonicalImportOrchestrator o = orchestrator(dir);
+        ReflectionTestUtils.setField(o, "currentStatus", new ImportStatus(
+                ImportStatus.State.RUNNING, "IMPORT_RUNNING", "running", 0, List.of(), null));
+
+        assertThatThrownBy(o::runImportAsync)
+                .isInstanceOf(DomainException.class)
+                .hasMessageContaining("already in progress");
+    }
+
+    @Test
+    void runImport_aggregatesDocumentSkips(@TempDir Path dir) throws Exception {
+        writeAllArtifacts(dir);
+        when(documentImporter.load(any())).thenReturn(new DocumentImporter.LoadResult(1,
+                List.of(new ImportStatus.SkippedFile("fake.pdf", ImportStatus.SkipReason.INVALID_PDF_SIGNATURE))));
+        CanonicalImportOrchestrator o = orchestrator(dir);
+
+        o.runImport();
+
+        assertThat(o.getStatus().skipped()).isEqualTo(1);
+        assertThat(o.getStatus().skippedFiles())
+                .extracting(ImportStatus.SkippedFile::filename)
+                .containsExactly("fake.pdf");
+    }
+}
diff --git a/backend/src/test/java/org/raddatz/familienarchiv/importing/CanonicalSheetReaderTest.java b/backend/src/test/java/org/raddatz/familienarchiv/importing/CanonicalSheetReaderTest.java
new file mode 100644
index 00000000..ee1d3650
--- /dev/null
+++ b/backend/src/test/java/org/raddatz/familienarchiv/importing/CanonicalSheetReaderTest.java
@@ -0,0 +1,115 @@
+package org.raddatz.familienarchiv.importing;
+
+import org.apache.poi.ss.usermodel.Row;
+import org.apache.poi.ss.usermodel.Sheet;
+import org.apache.poi.xssf.usermodel.XSSFWorkbook;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.io.TempDir;
+import org.raddatz.familienarchiv.exception.DomainException;
+
+import java.io.OutputStream;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.List;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+
+class CanonicalSheetReaderTest {
+
+    @Test
+    void readRows_mapsCellsByHeaderName(@TempDir Path tempDir) throws Exception {
+        Path xlsx = write(tempDir, List.of("index", "file"), List.of(List.of("W-0001", "scan.pdf")));
+
+        List<CanonicalSheetReader.Row> rows = CanonicalSheetReader.readRows(xlsx.toFile(), List.of("index", "file"));
+
+        assertThat(rows).hasSize(1);
+        assertThat(rows.get(0).get("index")).isEqualTo("W-0001");
+        assertThat(rows.get(0).get("file")).isEqualTo("scan.pdf");
+    }
+
+    @Test
+    void readRows_throwsBadRequest_whenRequiredHeaderMissing(@TempDir Path tempDir) throws Exception {
+        Path xlsx = write(tempDir, List.of("index"), List.of(List.of("W-0001")));
+
+        assertThatThrownBy(() -> CanonicalSheetReader.readRows(xlsx.toFile(), List.of("index", "file")))
+                .isInstanceOf(DomainException.class)
+                .hasMessageContaining("file");
+    }
+
+    @Test
+    void get_returnsEmptyString_forBlankCell(@TempDir Path tempDir) throws Exception {
+        Path xlsx = write(tempDir, List.of("index", "file"), List.of(List.of("W-0001", "")));
+
+        List<CanonicalSheetReader.Row> rows = CanonicalSheetReader.readRows(xlsx.toFile(), List.of("index", "file"));
+
+        assertThat(rows.get(0).get("file")).isEmpty();
+    }
+
+    @Test
+    void get_returnsEmptyString_forUnknownColumn(@TempDir Path tempDir) throws Exception {
+        Path xlsx = write(tempDir, List.of("index"), List.of(List.of("W-0001")));
+
+        List<CanonicalSheetReader.Row> rows = CanonicalSheetReader.readRows(xlsx.toFile(), List.of("index"));
+
+        assertThat(rows.get(0).get("does_not_exist")).isEmpty();
+    }
+
+    @Test
+    void get_returnsEmptyString_forTrailingColumns_whenRowShorterThanHeader(@TempDir Path tempDir) throws Exception {
+        // POI omits trailing empty cells, so a real-world artifact row can be narrower than
+        // the header. The missing columns must read as "" rather than throwing.
+        Path xlsx = write(tempDir,
+                List.of("index", "file", "summary"),
+                List.of(List.of("W-0001")));
+
+        List<CanonicalSheetReader.Row> rows = CanonicalSheetReader.readRows(xlsx.toFile(), List.of("index", "file", "summary"));
+
+        assertThat(rows.get(0).get("index")).isEqualTo("W-0001");
+        assertThat(rows.get(0).get("file")).isEmpty();
+        assertThat(rows.get(0).get("summary")).isEmpty();
+    }
+
+    @Test
+    void splitList_splitsOnPipe() {
+        assertThat(CanonicalSheetReader.splitList("a|b|c")).containsExactly("a", "b", "c");
+    }
+
+    @Test
+    void splitList_returnsEmptyList_forBlank() {
+        assertThat(CanonicalSheetReader.splitList("")).isEmpty();
+        assertThat(CanonicalSheetReader.splitList("   ")).isEmpty();
+    }
+
+    @Test
+    void splitList_returnsSingleElement_whenNoPipe() {
+        assertThat(CanonicalSheetReader.splitList("solo")).containsExactly("solo");
+    }
+
+    @Test
+    void splitList_trimsAndDropsEmptySegments() {
+        assertThat(CanonicalSheetReader.splitList("a| |b")).containsExactly("a", "b");
+    }
+
+    private Path write(Path dir, List<String> headers, List<List<String>> dataRows) throws Exception {
+        Path xlsx = dir.resolve("sheet.xlsx");
+        try (XSSFWorkbook wb = new XSSFWorkbook()) {
+            Sheet sheet = wb.createSheet("Sheet1");
+            Row header = sheet.createRow(0);
+            for (int i = 0; i < headers.size(); i++) {
+                header.createCell(i).setCellValue(headers.get(i));
+            }
+            for (int r = 0; r < dataRows.size(); r++) {
+                Row row = sheet.createRow(r + 1);
+                List<String> values = dataRows.get(r);
+                for (int c = 0; c < values.size(); c++) {
+                    row.createCell(c).setCellValue(values.get(c));
+                }
+            }
+            try (OutputStream out = Files.newOutputStream(xlsx)) {
+                wb.write(out);
+            }
+        }
+        return xlsx;
+    }
+}
diff --git a/backend/src/test/java/org/raddatz/familienarchiv/importing/DocumentImporterTest.java b/backend/src/test/java/org/raddatz/familienarchiv/importing/DocumentImporterTest.java
new file mode 100644
index 00000000..f0b2263b
--- /dev/null
+++ b/backend/src/test/java/org/raddatz/familienarchiv/importing/DocumentImporterTest.java
@@ -0,0 +1,459 @@
+package org.raddatz.familienarchiv.importing;
+
+import org.apache.poi.ss.usermodel.Row;
+import org.apache.poi.ss.usermodel.Sheet;
+import org.apache.poi.xssf.usermodel.XSSFWorkbook;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.junit.jupiter.api.io.TempDir;
+import org.mockito.Mock;
+import org.mockito.junit.jupiter.MockitoExtension;
+import org.raddatz.familienarchiv.document.Document;
+import org.raddatz.familienarchiv.document.DocumentService;
+import org.raddatz.familienarchiv.document.DocumentStatus;
+import org.raddatz.familienarchiv.document.ThumbnailAsyncRunner;
+import org.raddatz.familienarchiv.person.Person;
+import org.raddatz.familienarchiv.person.PersonService;
+import org.raddatz.familienarchiv.person.PersonUpsertCommand;
+import org.raddatz.familienarchiv.tag.Tag;
+import org.raddatz.familienarchiv.tag.TagService;
+import org.springframework.test.util.ReflectionTestUtils;
+import software.amazon.awssdk.core.sync.RequestBody;
+import software.amazon.awssdk.services.s3.S3Client;
+import software.amazon.awssdk.services.s3.model.PutObjectRequest;
+
+import java.io.File;
+import java.io.OutputStream;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.time.LocalDate;
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Optional;
+import java.util.UUID;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.lenient;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+@ExtendWith(MockitoExtension.class)
+class DocumentImporterTest {
+
+    @Mock DocumentService documentService;
+    @Mock PersonService personService;
+    @Mock TagService tagService;
+    @Mock S3Client s3Client;
+    @Mock ThumbnailAsyncRunner thumbnailAsyncRunner;
+
+    DocumentImporter importer;
+
+    @BeforeEach
+    void setUp() {
+        importer = new DocumentImporter(documentService, personService, tagService, s3Client, thumbnailAsyncRunner);
+        ReflectionTestUtils.setField(importer, "bucketName", "test-bucket");
+    }
+
+    // ─── security regression — ported from MassImportServiceTest — do not remove ─────
+
+    @Test
+    void isValidImportFilename_returnsFalse_whenNull() {
+        assertThat((Boolean) ReflectionTestUtils.invokeMethod(importer, "isValidImportFilename", (String) null)).isFalse();
+    }
+
+    @Test
+    void isValidImportFilename_returnsFalse_whenBlank() {
+        assertThat((Boolean) ReflectionTestUtils.invokeMethod(importer, "isValidImportFilename", "   ")).isFalse();
+    }
+
+    @Test
+    void isValidImportFilename_returnsFalse_whenForwardSlash() {
+        assertThat((Boolean) ReflectionTestUtils.invokeMethod(importer, "isValidImportFilename", "etc/passwd")).isFalse();
+    }
+
+    @Test
+    void isValidImportFilename_returnsFalse_whenBackslash() {
+        assertThat((Boolean) ReflectionTestUtils.invokeMethod(importer, "isValidImportFilename", "..\\etc\\passwd")).isFalse();
+    }
+
+    @Test
+    void isValidImportFilename_returnsFalse_whenDotDot() {
+        assertThat((Boolean) ReflectionTestUtils.invokeMethod(importer, "isValidImportFilename", "doc..evil.pdf")).isFalse();
+    }
+
+    @Test
+    void isValidImportFilename_returnsFalse_whenIsDotDot() {
+        assertThat((Boolean) ReflectionTestUtils.invokeMethod(importer, "isValidImportFilename", "..")).isFalse();
+    }
+
+    @Test
+    void isValidImportFilename_returnsFalse_whenAbsolutePath() {
+        assertThat((Boolean) ReflectionTestUtils.invokeMethod(importer, "isValidImportFilename", "/etc/passwd")).isFalse();
+    }
+
+    @Test
+    void isValidImportFilename_returnsFalse_whenNullByte() {
+        assertThat((Boolean) ReflectionTestUtils.invokeMethod(importer, "isValidImportFilename", "file\0.pdf")).isFalse();
+    }
+
+    @Test
+    void isValidImportFilename_returnsFalse_whenUnicodeDivisionSlash() {
+        assertThat((Boolean) ReflectionTestUtils.invokeMethod(importer, "isValidImportFilename", "foo∕bar.pdf")).isFalse();
+    }
+
+    @Test
+    void isValidImportFilename_returnsFalse_whenFullwidthSlash() {
+        assertThat((Boolean) ReflectionTestUtils.invokeMethod(importer, "isValidImportFilename", "foo／bar.pdf")).isFalse();
+    }
+
+    @Test
+    void isValidImportFilename_returnsFalse_whenReverseSolidusOperator() {
+        assertThat((Boolean) ReflectionTestUtils.invokeMethod(importer, "isValidImportFilename", "foo⧵bar.pdf")).isFalse();
+    }
+
+    @Test
+    void isValidImportFilename_returnsTrue_whenPlainBasename() {
+        assertThat((Boolean) ReflectionTestUtils.invokeMethod(importer, "isValidImportFilename", "document.pdf")).isTrue();
+    }
+
+    @Test
+    void isValidImportFilename_returnsTrue_whenLeadingDot() {
+        assertThat((Boolean) ReflectionTestUtils.invokeMethod(importer, "isValidImportFilename", ".hidden.pdf")).isTrue();
+    }
+
+    @Test
+    void isValidImportFilename_returnsTrue_whenHasSpaces() {
+        assertThat((Boolean) ReflectionTestUtils.invokeMethod(importer, "isValidImportFilename", "Brief an Oma.pdf")).isTrue();
+    }
+
+    @Test
+    void findFileRecursive_throwsDomainException_whenSymlinkEscapesImportDir(
+            @TempDir Path importDirPath, @TempDir Path outsideDir) throws Exception {
+        Path outsideFile = outsideDir.resolve("secret.pdf");
+        Files.writeString(outsideFile, "sensitive");
+        Files.createSymbolicLink(importDirPath.resolve("secret.pdf"), outsideFile);
+        ReflectionTestUtils.setField(importer, "importDir", importDirPath.toString());
+
+        org.assertj.core.api.Assertions.assertThatThrownBy(
+                        () -> ReflectionTestUtils.invokeMethod(importer, "findFileRecursive", "secret.pdf"))
+                .isInstanceOf(org.raddatz.familienarchiv.exception.DomainException.class);
+    }
+
+    // ─── path traversal in the file column cannot escape importDir ───────────────────
+
+    @Test
+    void load_rejectsFileColumn_whenBasenameIsTraversalToken(@TempDir Path tempDir) throws Exception {
+        // A file column whose basename is itself a traversal token must be rejected
+        // outright, never used for disk I/O.
+        ReflectionTestUtils.setField(importer, "importDir", tempDir.toString());
+        Path xlsx = writeDocs(tempDir, docRow("W-0001", "evil/..", "", "", "", "", "", "", "", ""));
+
+        DocumentImporter.LoadResult result = importer.load(xlsx.toFile());
+
+        assertThat(result.skippedFiles())
+                .extracting(ImportStatus.SkippedFile::reason)
+                .containsExactly(ImportStatus.SkipReason.INVALID_FILENAME_PATH_TRAVERSAL);
+        verify(documentService, never()).save(any());
+    }
+
+    @Test
+    void load_traversalFileColumn_cannotEscapeImportDir_yieldsPlaceholder(@TempDir Path tempDir) throws Exception {
+        // ../../etc/cron.d/x reduces to basename "x"; the disk lookup is confined to
+        // importDir, so no file is found, nothing is uploaded, and the row becomes a
+        // metadata-only PLACEHOLDER — the file outside importDir is never read.
+        ReflectionTestUtils.setField(importer, "importDir", tempDir.toString());
+        when(documentService.findByOriginalFilename("W-0001")).thenReturn(Optional.empty());
+        when(documentService.save(any())).thenAnswer(inv -> inv.getArgument(0));
+        Path xlsx = writeDocs(tempDir, docRow("W-0001", "../../etc/cron.d/x", "", "", "", "", "", "", "", ""));
+
+        importer.load(xlsx.toFile());
+
+        verify(s3Client, never()).putObject(any(PutObjectRequest.class), any(RequestBody.class));
+        verify(documentService).save(org.mockito.ArgumentMatchers.argThat(d -> d.getStatus() == DocumentStatus.PLACEHOLDER));
+    }
+
+    // ─── PDF magic-byte guard — ported — do not remove ──────────────────────────────
+
+    @Test
+    void load_skipsFile_whenNotPdfMagicBytes(@TempDir Path tempDir) throws Exception {
+        ReflectionTestUtils.setField(importer, "importDir", tempDir.toString());
+        Files.writeString(tempDir.resolve("W-0001.pdf"), "not a pdf");
+        lenient().when(documentService.findByOriginalFilename(any())).thenReturn(Optional.empty());
+        Path xlsx = writeDocs(tempDir, docRow("W-0001", "..\\__scan\\W-0001.pdf", "", "", "", "", "", "", "", ""));
+
+        DocumentImporter.LoadResult result = importer.load(xlsx.toFile());
+
+        assertThat(result.skippedFiles())
+                .extracting(ImportStatus.SkippedFile::reason)
+                .containsExactly(ImportStatus.SkipReason.INVALID_PDF_SIGNATURE);
+        verify(s3Client, never()).putObject(any(PutObjectRequest.class), any(RequestBody.class));
+    }
+
+    @Test
+    void load_skipsFile_whenMagicByteCheckThrowsIoException(@TempDir Path tempDir) throws Exception {
+        ReflectionTestUtils.setField(importer, "importDir", tempDir.toString());
+        Files.writeString(tempDir.resolve("W-0001.pdf"), "content");
+        lenient().when(documentService.findByOriginalFilename(any())).thenReturn(Optional.empty());
+        Path xlsx = writeDocs(tempDir, docRow("W-0001", "..\\__scan\\W-0001.pdf", "", "", "", "", "", "", "", ""));
+
+        DocumentImporter spyImporter = org.mockito.Mockito.spy(importer);
+        org.mockito.Mockito.doThrow(new java.io.IOException("read error"))
+                .when(spyImporter).openFileStream(any(File.class));
+
+        DocumentImporter.LoadResult result = spyImporter.load(xlsx.toFile());
+
+        assertThat(result.skippedFiles())
+                .extracting(ImportStatus.SkippedFile::reason)
+                .containsExactly(ImportStatus.SkipReason.FILE_READ_ERROR);
+    }
+
+    @Test
+    void load_skipsAlreadyExists_whenDocumentUploadedNotPlaceholder(@TempDir Path tempDir) throws Exception {
+        ReflectionTestUtils.setField(importer, "importDir", tempDir.toString());
+        Document existing = Document.builder().id(UUID.randomUUID())
+                .originalFilename("W-0001").status(DocumentStatus.UPLOADED).build();
+        when(documentService.findByOriginalFilename("W-0001")).thenReturn(Optional.of(existing));
+        Path xlsx = writeDocs(tempDir, docRow("W-0001", "", "", "", "", "", "", "", "", ""));
+
+        DocumentImporter.LoadResult result = importer.load(xlsx.toFile());
+
+        assertThat(result.skippedFiles())
+                .extracting(ImportStatus.SkippedFile::reason)
+                .containsExactly(ImportStatus.SkipReason.ALREADY_EXISTS);
+        verify(documentService, never()).save(any());
+    }
+
+    // ─── file column drives status: present → UPLOADED, empty → PLACEHOLDER ───────────
+
+    @Test
+    void load_uploadsToS3_andSetsStatusUploaded_whenFilePresent(@TempDir Path tempDir) throws Exception {
+        ReflectionTestUtils.setField(importer, "importDir", tempDir.toString());
+        byte[] pdf = {0x25, 0x50, 0x44, 0x46, 0x2D};
+        Files.write(tempDir.resolve("W-0001.pdf"), pdf);
+        when(documentService.findByOriginalFilename("W-0001")).thenReturn(Optional.empty());
+        when(documentService.save(any())).thenAnswer(inv -> inv.getArgument(0));
+        Path xlsx = writeDocs(tempDir, docRow("W-0001", "..\\__scan\\W-0001.pdf", "", "", "", "", "", "", "", ""));
+
+        importer.load(xlsx.toFile());
+
+        verify(s3Client).putObject(any(PutObjectRequest.class), any(RequestBody.class));
+        verify(documentService).save(org.mockito.ArgumentMatchers.argThat(d -> d.getStatus() == DocumentStatus.UPLOADED));
+    }
+
+    @Test
+    void load_setsStatusPlaceholder_whenFileColumnEmpty(@TempDir Path tempDir) throws Exception {
+        ReflectionTestUtils.setField(importer, "importDir", tempDir.toString());
+        when(documentService.findByOriginalFilename("W-0099")).thenReturn(Optional.empty());
+        when(documentService.save(any())).thenAnswer(inv -> inv.getArgument(0));
+        Path xlsx = writeDocs(tempDir, docRow("W-0099", "", "", "", "", "", "", "", "", ""));
+
+        importer.load(xlsx.toFile());
+
+        verify(documentService).save(org.mockito.ArgumentMatchers.argThat(d -> d.getStatus() == DocumentStatus.PLACEHOLDER));
+        verify(s3Client, never()).putObject(any(PutObjectRequest.class), any(RequestBody.class));
+    }
+
+    // ─── attribution routing — register-first + always retain raw ────────────────────
+
+    @Test
+    void load_linksRegisterSender_andRetainsRawSenderText(@TempDir Path tempDir) throws Exception {
+        ReflectionTestUtils.setField(importer, "importDir", tempDir.toString());
+        Person walter = Person.builder().id(UUID.randomUUID()).sourceRef("de-gruyter-walter")
+                .firstName("Walter").lastName("de Gruyter").build();
+        when(documentService.findByOriginalFilename("W-0001")).thenReturn(Optional.empty());
+        when(documentService.save(any())).thenAnswer(inv -> inv.getArgument(0));
+        when(personService.findBySourceRef("de-gruyter-walter")).thenReturn(Optional.of(walter));
+        Path xlsx = writeDocs(tempDir, docRow("W-0001", "", "de-gruyter-walter", "Walter de Gruyter",
+                "", "", "", "", "", ""));
+
+        importer.load(xlsx.toFile());
+
+        verify(documentService).save(org.mockito.ArgumentMatchers.argThat(d ->
+                d.getSender() == walter && "Walter de Gruyter".equals(d.getSenderText())));
+    }
+
+    @Test
+    void load_createsProvisionalSender_whenSlugUnmatchedInRegister(@TempDir Path tempDir) throws Exception {
+        ReflectionTestUtils.setField(importer, "importDir", tempDir.toString());
+        Person provisional = Person.builder().id(UUID.randomUUID()).sourceRef("schwester-hanni")
+                .lastName("Schwester Hanni").provisional(true).build();
+        when(documentService.findByOriginalFilename("W-0002")).thenReturn(Optional.empty());
+        when(documentService.save(any())).thenAnswer(inv -> inv.getArgument(0));
+        when(personService.findBySourceRef("schwester-hanni")).thenReturn(Optional.empty());
+        when(personService.upsertBySourceRef(any())).thenReturn(provisional);
+        Path xlsx = writeDocs(tempDir, docRow("W-0002", "", "schwester-hanni", "Schwester Hanni",
+                "", "", "", "", "", ""));
+
+        importer.load(xlsx.toFile());
+
+        org.mockito.ArgumentCaptor<PersonUpsertCommand> captor =
+                org.mockito.ArgumentCaptor.forClass(PersonUpsertCommand.class);
+        verify(personService).upsertBySourceRef(captor.capture());
+        assertThat(captor.getValue().provisional()).isTrue();
+        assertThat(captor.getValue().lastName()).isEqualTo("Schwester Hanni");
+    }
+
+    @Test
+    void load_createsNoSenderPerson_whenSlugEmptyButRawPresent(@TempDir Path tempDir) throws Exception {
+        ReflectionTestUtils.setField(importer, "importDir", tempDir.toString());
+        when(documentService.findByOriginalFilename("W-0003")).thenReturn(Optional.empty());
+        when(documentService.save(any())).thenAnswer(inv -> inv.getArgument(0));
+        Path xlsx = writeDocs(tempDir, docRow("W-0003", "", "", "?",
+                "", "", "", "", "", ""));
+
+        importer.load(xlsx.toFile());
+
+        verify(personService, never()).findBySourceRef(any());
+        verify(personService, never()).upsertBySourceRef(any());
+        verify(documentService).save(org.mockito.ArgumentMatchers.argThat(d ->
+                d.getSender() == null && "?".equals(d.getSenderText())));
+    }
+
+    @Test
+    void load_splitsMultipleReceivers_andRetainsRawReceiverText(@TempDir Path tempDir) throws Exception {
+        ReflectionTestUtils.setField(importer, "importDir", tempDir.toString());
+        Person herbert = Person.builder().id(UUID.randomUUID()).sourceRef("cram-herbert").lastName("Cram").build();
+        Person clara = Person.builder().id(UUID.randomUUID()).sourceRef("clara").lastName("Clara").build();
+        when(documentService.findByOriginalFilename("W-0004")).thenReturn(Optional.empty());
+        when(documentService.save(any())).thenAnswer(inv -> inv.getArgument(0));
+        when(personService.findBySourceRef("cram-herbert")).thenReturn(Optional.of(herbert));
+        when(personService.findBySourceRef("clara")).thenReturn(Optional.of(clara));
+        Path xlsx = writeDocs(tempDir, docRow("W-0004", "", "", "",
+                "cram-herbert|clara", "Herbert Cram|Clara", "", "", "", ""));
+
+        importer.load(xlsx.toFile());
+
+        verify(documentService).save(org.mockito.ArgumentMatchers.argThat(d ->
+                d.getReceivers().size() == 2
+                        && d.getReceivers().contains(herbert)
+                        && d.getReceivers().contains(clara)
+                        && "Herbert Cram|Clara".equals(d.getReceiverText())));
+    }
+
+    // ─── clean date values parse without semantic logic ──────────────────────────────
+
+    @Test
+    void load_parsesCleanDateAndPrecision(@TempDir Path tempDir) throws Exception {
+        ReflectionTestUtils.setField(importer, "importDir", tempDir.toString());
+        when(documentService.findByOriginalFilename("W-0005")).thenReturn(Optional.empty());
+        when(documentService.save(any())).thenAnswer(inv -> inv.getArgument(0));
+        Path xlsx = writeDocs(tempDir, docRow("W-0005", "", "", "",
+                "", "", "1916-06-01", "1.6.1916", "MONTH", ""));
+
+        importer.load(xlsx.toFile());
+
+        verify(documentService).save(org.mockito.ArgumentMatchers.argThat(d ->
+                LocalDate.of(1916, 6, 1).equals(d.getDocumentDate())
+                        && d.getMetaDatePrecision() == org.raddatz.familienarchiv.document.DatePrecision.MONTH
+                        && "1.6.1916".equals(d.getMetaDateRaw())));
+    }
+
+    @Test
+    void load_attachesTagBySourceRef(@TempDir Path tempDir) throws Exception {
+        ReflectionTestUtils.setField(importer, "importDir", tempDir.toString());
+        Tag tag = Tag.builder().id(UUID.randomUUID()).name("Brautbriefe").sourceRef("Themen/Brautbriefe").build();
+        when(documentService.findByOriginalFilename("W-0006")).thenReturn(Optional.empty());
+        when(documentService.save(any())).thenAnswer(inv -> inv.getArgument(0));
+        when(tagService.findBySourceRef("Themen/Brautbriefe")).thenReturn(Optional.of(tag));
+        Path xlsx = writeDocs(tempDir, docRowWithTag("W-0006", "Themen/Brautbriefe"));
+
+        importer.load(xlsx.toFile());
+
+        verify(documentService).save(org.mockito.ArgumentMatchers.argThat(d -> d.getTags().contains(tag)));
+    }
+
+    // ─── idempotency — update existing document in place by index ─────────────────────
+
+    @Test
+    void load_updatesExistingDocumentInPlace_whenIndexExists(@TempDir Path tempDir) throws Exception {
+        ReflectionTestUtils.setField(importer, "importDir", tempDir.toString());
+        Document existing = Document.builder().id(UUID.randomUUID())
+                .originalFilename("W-0007").status(DocumentStatus.PLACEHOLDER).build();
+        when(documentService.findByOriginalFilename("W-0007")).thenReturn(Optional.of(existing));
+        when(documentService.save(any())).thenAnswer(inv -> inv.getArgument(0));
+        Path xlsx = writeDocs(tempDir, docRow("W-0007", "", "", "", "", "", "", "", "", ""));
+
+        importer.load(xlsx.toFile());
+
+        verify(documentService).save(org.mockito.ArgumentMatchers.argThat(d -> d.getId().equals(existing.getId())));
+    }
+
+    // ─── canonical collections are authoritative — re-import prunes removed links ──────
+
+    @Test
+    void load_prunesReceiversAndTags_whenCanonicalRowShrinks(@TempDir Path tempDir) throws Exception {
+        ReflectionTestUtils.setField(importer, "importDir", tempDir.toString());
+        Person staleReceiver = Person.builder().id(UUID.randomUUID()).sourceRef("stale-receiver").lastName("Stale").build();
+        Tag staleTag = Tag.builder().id(UUID.randomUUID()).name("Stale").sourceRef("Themen/Stale").build();
+        Document existing = Document.builder().id(UUID.randomUUID())
+                .originalFilename("W-0008").status(DocumentStatus.PLACEHOLDER).build();
+        existing.getReceivers().add(staleReceiver);
+        existing.getTags().add(staleTag);
+        when(documentService.findByOriginalFilename("W-0008")).thenReturn(Optional.of(existing));
+        when(documentService.save(any())).thenAnswer(inv -> inv.getArgument(0));
+        // The canonical row now carries no receiver and no tag: both stale links must go.
+        Path xlsx = writeDocs(tempDir, docRow("W-0008", "", "", "", "", "", "", "", "", ""));
+
+        importer.load(xlsx.toFile());
+
+        verify(documentService).save(org.mockito.ArgumentMatchers.argThat(d ->
+                d.getReceivers().isEmpty() && d.getTags().isEmpty()));
+    }
+
+    // ─── helpers ─────────────────────────────────────────────────────────────────────
+
+    private Map<String, String> docRow(String index, String file, String senderId, String senderName,
+                                        String receiverIds, String receiverNames, String dateIso,
+                                        String dateRaw, String datePrecision, String dateEnd) {
+        Map<String, String> r = new LinkedHashMap<>();
+        r.put("index", index);
+        r.put("file", file);
+        r.put("sender_person_id", senderId);
+        r.put("sender_name", senderName);
+        r.put("receiver_person_ids", receiverIds);
+        r.put("receiver_names", receiverNames);
+        r.put("date_iso", dateIso);
+        r.put("date_raw", dateRaw);
+        r.put("date_precision", datePrecision);
+        r.put("date_end", dateEnd);
+        r.put("location", "");
+        r.put("tags", "");
+        r.put("summary", "");
+        return r;
+    }
+
+    private Map<String, String> docRowWithTag(String index, String tagPath) {
+        Map<String, String> r = docRow(index, "", "", "", "", "", "", "", "", "");
+        r.put("tags", tagPath);
+        return r;
+    }
+
+    @SafeVarargs
+    private Path writeDocs(Path dir, Map<String, String>... rows) throws Exception {
+        Path xlsx = dir.resolve("canonical-documents.xlsx");
+        List<String> headers = List.of("index", "file", "sender_person_id", "sender_name",
+                "receiver_person_ids", "receiver_names", "date_iso", "date_raw", "date_precision",
+                "date_end", "location", "tags", "summary");
+        try (XSSFWorkbook wb = new XSSFWorkbook()) {
+            Sheet sheet = wb.createSheet("Sheet1");
+            Row header = sheet.createRow(0);
+            for (int i = 0; i < headers.size(); i++) {
+                header.createCell(i).setCellValue(headers.get(i));
+            }
+            for (int r = 0; r < rows.length; r++) {
+                Row row = sheet.createRow(r + 1);
+                for (int c = 0; c < headers.size(); c++) {
+                    row.createCell(c).setCellValue(rows[r].getOrDefault(headers.get(c), ""));
+                }
+            }
+            try (OutputStream out = Files.newOutputStream(xlsx)) {
+                wb.write(out);
+            }
+        }
+        return xlsx;
+    }
+}
diff --git a/backend/src/test/java/org/raddatz/familienarchiv/importing/MassImportServiceTest.java b/backend/src/test/java/org/raddatz/familienarchiv/importing/MassImportServiceTest.java
deleted file mode 100644
index d87d28c1..00000000
--- a/backend/src/test/java/org/raddatz/familienarchiv/importing/MassImportServiceTest.java
+++ /dev/null
@@ -1,896 +0,0 @@
-package org.raddatz.familienarchiv.importing;
-
-import org.junit.jupiter.api.BeforeEach;
-import org.junit.jupiter.api.Test;
-import org.junit.jupiter.api.extension.ExtendWith;
-import org.junit.jupiter.api.io.TempDir;
-import org.mockito.Mock;
-import org.mockito.junit.jupiter.MockitoExtension;
-import org.raddatz.familienarchiv.exception.DomainException;
-import org.raddatz.familienarchiv.document.Document;
-import org.raddatz.familienarchiv.document.DocumentService;
-import org.raddatz.familienarchiv.document.DocumentStatus;
-import org.raddatz.familienarchiv.document.ThumbnailAsyncRunner;
-import org.raddatz.familienarchiv.person.Person;
-import org.raddatz.familienarchiv.tag.Tag;
-import org.raddatz.familienarchiv.tag.TagService;
-import org.raddatz.familienarchiv.person.PersonService;
-import org.springframework.test.util.ReflectionTestUtils;
-import software.amazon.awssdk.core.sync.RequestBody;
-import software.amazon.awssdk.services.s3.S3Client;
-import software.amazon.awssdk.services.s3.model.PutObjectRequest;
-
-import org.apache.poi.xssf.usermodel.XSSFWorkbook;
-import org.xml.sax.SAXParseException;
-
-import java.io.File;
-import java.io.OutputStream;
-import java.io.ByteArrayOutputStream;
-import java.nio.charset.StandardCharsets;
-import java.nio.file.Files;
-import java.nio.file.Path;
-import java.time.LocalDate;
-import java.time.LocalDateTime;
-import java.util.ArrayList;
-import java.util.List;
-import java.util.Optional;
-import java.util.UUID;
-import java.util.zip.ZipEntry;
-import java.util.zip.ZipOutputStream;
-
-import static org.assertj.core.api.Assertions.assertThat;
-import static org.assertj.core.api.Assertions.assertThatThrownBy;
-import static org.mockito.ArgumentMatchers.any;
-import static org.mockito.Mockito.*;
-
-@ExtendWith(MockitoExtension.class)
-class MassImportServiceTest {
-
-    @Mock DocumentService documentService;
-    @Mock PersonService personService;
-    @Mock TagService tagService;
-    @Mock S3Client s3Client;
-    @Mock ThumbnailAsyncRunner thumbnailAsyncRunner;
-
-    MassImportService service;
-
-    @BeforeEach
-    void setUp() {
-        service = new MassImportService(documentService, personService, tagService, s3Client, thumbnailAsyncRunner);
-        ReflectionTestUtils.setField(service, "bucketName", "test-bucket");
-        ReflectionTestUtils.setField(service, "importDir", "/import");
-        ReflectionTestUtils.setField(service, "colIndex", 0);
-        ReflectionTestUtils.setField(service, "colBox", 1);
-        ReflectionTestUtils.setField(service, "colFolder", 2);
-        ReflectionTestUtils.setField(service, "colSender", 3);
-        ReflectionTestUtils.setField(service, "colReceivers", 5);
-        ReflectionTestUtils.setField(service, "colDate", 7);
-        ReflectionTestUtils.setField(service, "colLocation", 9);
-        ReflectionTestUtils.setField(service, "colTags", 10);
-        ReflectionTestUtils.setField(service, "colSummary", 11);
-        ReflectionTestUtils.setField(service, "colTranscription", 13);
-    }
-
-    // ─── getStatus ────────────────────────────────────────────────────────────
-
-    @Test
-    void getStatus_returnsIdleByDefault() {
-        assertThat(service.getStatus().state()).isEqualTo(MassImportService.State.IDLE);
-    }
-
-    @Test
-    void getStatus_hasStatusCode_IMPORT_IDLE_byDefault() {
-        assertThat(service.getStatus().statusCode()).isEqualTo("IMPORT_IDLE");
-    }
-
-    // ─── runImportAsync ───────────────────────────────────────────────────────
-
-    @Test
-    void runImportAsync_setsFailedStatus_whenImportDirectoryDoesNotExist() {
-        // /import directory doesn't exist in test environment → IOException → IMPORT_FAILED_INTERNAL
-        service.runImportAsync();
-
-        assertThat(service.getStatus().state()).isEqualTo(MassImportService.State.FAILED);
-        assertThat(service.getStatus().statusCode()).isEqualTo("IMPORT_FAILED_INTERNAL");
-    }
-
-    @Test
-    void runImportAsync_readsFromConfiguredImportDir(@TempDir Path tempDir) {
-        // Empty temp dir → findSpreadsheetFile throws "no spreadsheet" with the
-        // configured path in the message. Proves the field, not a constant,
-        // drives the lookup.
-        ReflectionTestUtils.setField(service, "importDir", tempDir.toString());
-
-        service.runImportAsync();
-
-        assertThat(service.getStatus().state()).isEqualTo(MassImportService.State.FAILED);
-        assertThat(service.getStatus().message()).contains(tempDir.toString());
-    }
-
-    @Test
-    void runImportAsync_setsStatusCode_IMPORT_FAILED_NO_SPREADSHEET_whenDirIsEmpty(@TempDir Path tempDir) {
-        ReflectionTestUtils.setField(service, "importDir", tempDir.toString());
-
-        service.runImportAsync();
-
-        assertThat(service.getStatus().statusCode()).isEqualTo("IMPORT_FAILED_NO_SPREADSHEET");
-    }
-
-    @Test
-    void runImportAsync_setsStatusCode_IMPORT_DONE_whenSpreadsheetHasNoDataRows(@TempDir Path tempDir) throws Exception {
-        Path xlsx = tempDir.resolve("import.xlsx");
-        try (XSSFWorkbook wb = new XSSFWorkbook()) {
-            wb.createSheet("Sheet1");
-            try (OutputStream out = Files.newOutputStream(xlsx)) {
-                wb.write(out);
-            }
-        }
-        ReflectionTestUtils.setField(service, "importDir", tempDir.toString());
-
-        service.runImportAsync();
-
-        assertThat(service.getStatus().statusCode()).isEqualTo("IMPORT_DONE");
-    }
-
-    @Test
-    void runImportAsync_throwsConflict_whenAlreadyRunning() {
-        MassImportService.ImportStatus running = new MassImportService.ImportStatus(
-                MassImportService.State.RUNNING, "IMPORT_RUNNING", "Running...", 0, List.of(), LocalDateTime.now());
-        ReflectionTestUtils.setField(service, "currentStatus", running);
-
-        assertThatThrownBy(() -> service.runImportAsync())
-                .isInstanceOf(DomainException.class)
-                .hasMessageContaining("already in progress");
-    }
-
-    // ─── importSingleDocument — skip already uploaded ─────────────────────────
-
-    @Test
-    void importSingleDocument_skips_whenDocumentAlreadyUploadedNotPlaceholder() {
-        Document existing = Document.builder()
-                .id(UUID.randomUUID())
-                .originalFilename("doc001.pdf")
-                .status(DocumentStatus.UPLOADED)
-                .build();
-        when(documentService.findByOriginalFilename("doc001.pdf")).thenReturn(Optional.of(existing));
-
-        Optional<MassImportService.SkipReason> result = service.importSingleDocument(minimalCells("doc001.pdf"), Optional.empty(), "doc001.pdf", "doc001");
-
-        verify(documentService, never()).save(any());
-        assertThat(result).isPresent().contains(MassImportService.SkipReason.ALREADY_EXISTS);
-    }
-
-    // ─── importSingleDocument — already-exists guard fires before file I/O ─────
-
-    @Test
-    void importSingleDocument_skipsWithAlreadyExists_whenDocumentUploadedAndFileIsPresent(@TempDir Path tempDir) throws Exception {
-        // Document already exists with status UPLOADED (not PLACEHOLDER).
-        // A physical PDF file is also present on disk (valid magic bytes).
-        // Expected: ALREADY_EXISTS is returned and no S3 upload is attempted —
-        // the guard fires before any file I/O, so no partial processing occurs.
-        Document existing = Document.builder()
-                .id(UUID.randomUUID())
-                .originalFilename("present.pdf")
-                .status(DocumentStatus.UPLOADED)
-                .build();
-        when(documentService.findByOriginalFilename("present.pdf")).thenReturn(Optional.of(existing));
-
-        Path physicalFile = tempDir.resolve("present.pdf");
-        byte[] pdfHeader = {0x25, 0x50, 0x44, 0x46, 0x2D}; // %PDF-
-        Files.write(physicalFile, pdfHeader);
-
-        Optional<MassImportService.SkipReason> result = service.importSingleDocument(
-                minimalCells("present.pdf"), Optional.of(physicalFile.toFile()), "present.pdf", "present");
-
-        assertThat(result).isPresent().contains(MassImportService.SkipReason.ALREADY_EXISTS);
-        verify(s3Client, never()).putObject(any(PutObjectRequest.class), any(RequestBody.class));
-        verify(documentService, never()).save(any());
-    }
-
-    // ─── importSingleDocument — S3 failure surfaced in skippedFiles ──────────
-
-    @Test
-    void runImportAsync_addsS3UploadFailed_toSkippedFiles_whenS3Throws(@TempDir Path tempDir) throws Exception {
-        byte[] pdfHeader = {0x25, 0x50, 0x44, 0x46, 0x2D}; // %PDF-
-        Files.write(tempDir.resolve("upload_fail.pdf"), pdfHeader);
-        buildMinimalImportXlsx(tempDir, "upload_fail.pdf");
-        ReflectionTestUtils.setField(service, "importDir", tempDir.toString());
-        when(documentService.findByOriginalFilename("upload_fail.pdf")).thenReturn(Optional.empty());
-        doThrow(new RuntimeException("S3 unavailable"))
-                .when(s3Client).putObject(any(PutObjectRequest.class), any(RequestBody.class));
-
-        service.runImportAsync();
-
-        assertThat(service.getStatus().skipped()).isEqualTo(1);
-        assertThat(service.getStatus().skippedFiles())
-                .extracting(MassImportService.SkippedFile::filename, MassImportService.SkippedFile::reason)
-                .containsExactly(org.assertj.core.groups.Tuple.tuple("upload_fail.pdf", MassImportService.SkipReason.S3_UPLOAD_FAILED));
-    }
-
-    @Test
-    void runImportAsync_addsAlreadyExists_toSkippedFiles_whenDocumentAlreadyUploaded(@TempDir Path tempDir) throws Exception {
-        buildMinimalImportXlsx(tempDir, "existing.pdf");
-        ReflectionTestUtils.setField(service, "importDir", tempDir.toString());
-        Document existing = Document.builder()
-                .id(UUID.randomUUID())
-                .originalFilename("existing.pdf")
-                .status(DocumentStatus.UPLOADED)
-                .build();
-        when(documentService.findByOriginalFilename("existing.pdf")).thenReturn(Optional.of(existing));
-
-        service.runImportAsync();
-
-        assertThat(service.getStatus().skipped()).isEqualTo(1);
-        assertThat(service.getStatus().skippedFiles())
-                .extracting(MassImportService.SkippedFile::reason)
-                .containsExactly(MassImportService.SkipReason.ALREADY_EXISTS);
-    }
-
-    // ─── importSingleDocument — create new document (metadata only) ───────────
-
-    @Test
-    void importSingleDocument_createsNewDocument_whenNotExists() {
-        when(documentService.findByOriginalFilename("doc002.pdf")).thenReturn(Optional.empty());
-        when(documentService.save(any())).thenAnswer(inv -> inv.getArgument(0));
-
-        service.importSingleDocument(minimalCells("doc002.pdf"), Optional.empty(), "doc002.pdf", "doc002");
-
-        verify(documentService).save(argThat(d ->
-                d.getOriginalFilename().equals("doc002.pdf")
-                        && d.getStatus() == DocumentStatus.PLACEHOLDER));
-    }
-
-    // ─── importSingleDocument — update existing placeholder ──────────────────
-
-    @Test
-    void importSingleDocument_updatesExistingPlaceholder() {
-        Document placeholder = Document.builder()
-                .id(UUID.randomUUID())
-                .originalFilename("existing.pdf")
-                .status(DocumentStatus.PLACEHOLDER)
-                .build();
-        when(documentService.findByOriginalFilename("existing.pdf")).thenReturn(Optional.of(placeholder));
-        when(documentService.save(any())).thenAnswer(inv -> inv.getArgument(0));
-
-        service.importSingleDocument(minimalCells("existing.pdf"), Optional.empty(), "existing.pdf", "existing");
-
-        verify(documentService).save(same(placeholder));
-    }
-
-    // ─── importSingleDocument — with file (S3 upload) ─────────────────────────
-
-    @Test
-    void importSingleDocument_uploadsFileToS3_andSetsStatusUploaded(@TempDir Path tempDir) throws Exception {
-        Path tempFile = tempDir.resolve("doc003.pdf");
-        Files.write(tempFile, "PDF content".getBytes());
-
-        when(documentService.findByOriginalFilename("doc003.pdf")).thenReturn(Optional.empty());
-        when(documentService.save(any())).thenAnswer(inv -> inv.getArgument(0));
-
-        service.importSingleDocument(
-                minimalCells("doc003.pdf"), Optional.of(tempFile.toFile()), "doc003.pdf", "doc003");
-
-        verify(s3Client).putObject(any(PutObjectRequest.class), any(RequestBody.class));
-        verify(documentService).save(argThat(d -> d.getStatus() == DocumentStatus.UPLOADED));
-    }
-
-    @Test
-    void importSingleDocument_returnsS3UploadFailed_whenS3UploadFails(@TempDir Path tempDir) throws Exception {
-        Path tempFile = tempDir.resolve("fail.pdf");
-        Files.write(tempFile, "data".getBytes());
-
-        when(documentService.findByOriginalFilename("fail.pdf")).thenReturn(Optional.empty());
-        doThrow(new RuntimeException("S3 error"))
-                .when(s3Client).putObject(any(PutObjectRequest.class), any(RequestBody.class));
-
-        Optional<MassImportService.SkipReason> result = service.importSingleDocument(
-                minimalCells("fail.pdf"), Optional.of(tempFile.toFile()), "fail.pdf", "fail");
-
-        verify(documentService, never()).save(any());
-        assertThat(result).isPresent().contains(MassImportService.SkipReason.S3_UPLOAD_FAILED);
-    }
-
-    // ─── importSingleDocument — sender handling ───────────────────────────────
-
-    @Test
-    void importSingleDocument_setsNullSender_whenSenderCellIsBlank() {
-        when(documentService.findByOriginalFilename("nosender.pdf")).thenReturn(Optional.empty());
-        when(documentService.save(any())).thenAnswer(inv -> inv.getArgument(0));
-
-        List<String> cells = buildCells("nosender.pdf", "", "", "");
-        service.importSingleDocument(cells, Optional.empty(), "nosender.pdf", "nosender");
-
-        verify(documentService).save(argThat(d -> d.getSender() == null));
-        verify(personService, never()).findOrCreateByAlias(any());
-    }
-
-    @Test
-    void importSingleDocument_createsSender_whenSenderCellIsNonBlank() {
-        Person sender = Person.builder().id(UUID.randomUUID()).firstName("Walter").lastName("Müller").build();
-        when(documentService.findByOriginalFilename("withsender.pdf")).thenReturn(Optional.empty());
-        when(documentService.save(any())).thenAnswer(inv -> inv.getArgument(0));
-        when(personService.findOrCreateByAlias("Walter Müller")).thenReturn(sender);
-
-        List<String> cells = buildCells("withsender.pdf", "Walter Müller", "", "");
-        service.importSingleDocument(cells, Optional.empty(), "withsender.pdf", "withsender");
-
-        verify(personService).findOrCreateByAlias("Walter Müller");
-        verify(documentService).save(argThat(d -> d.getSender() == sender));
-    }
-
-    // ─── importSingleDocument — tag handling ─────────────────────────────────
-
-    @Test
-    void importSingleDocument_createsTag_whenTagCellIsNonBlank() {
-        Tag tag = Tag.builder().id(UUID.randomUUID()).name("Familie").build();
-        when(documentService.findByOriginalFilename("tagged.pdf")).thenReturn(Optional.empty());
-        when(documentService.save(any())).thenAnswer(inv -> inv.getArgument(0));
-        when(tagService.findOrCreate("Familie")).thenReturn(tag);
-
-        List<String> cells = buildCells("tagged.pdf", "", "", "Familie");
-        service.importSingleDocument(cells, Optional.empty(), "tagged.pdf", "tagged");
-
-        verify(tagService).findOrCreate("Familie");
-    }
-
-    @Test
-    void importSingleDocument_doesNotCreateTag_whenTagCellIsBlank() {
-        when(documentService.findByOriginalFilename("notag.pdf")).thenReturn(Optional.empty());
-        when(documentService.save(any())).thenAnswer(inv -> inv.getArgument(0));
-
-        List<String> cells = buildCells("notag.pdf", "", "", "");
-        service.importSingleDocument(cells, Optional.empty(), "notag.pdf", "notag");
-
-        verify(tagService, never()).findOrCreate(any());
-    }
-
-    // ─── importSingleDocument — metadataComplete heuristic ───────────────────
-
-    @Test
-    void importSingleDocument_metadataComplete_whenSenderPresent() {
-        Person sender = Person.builder().id(UUID.randomUUID()).firstName("A").lastName("B").build();
-        when(documentService.findByOriginalFilename("meta.pdf")).thenReturn(Optional.empty());
-        when(documentService.save(any())).thenAnswer(inv -> inv.getArgument(0));
-        when(personService.findOrCreateByAlias("A B")).thenReturn(sender);
-
-        List<String> cells = buildCells("meta.pdf", "A B", "", "");
-        service.importSingleDocument(cells, Optional.empty(), "meta.pdf", "meta");
-
-        verify(documentService).save(argThat(Document::isMetadataComplete));
-    }
-
-    @Test
-    void importSingleDocument_metadataIncomplete_whenNoKeyFieldsPresent() {
-        when(documentService.findByOriginalFilename("nometa.pdf")).thenReturn(Optional.empty());
-        when(documentService.save(any())).thenAnswer(inv -> inv.getArgument(0));
-
-        List<String> cells = buildCells("nometa.pdf", "", "", "");
-        service.importSingleDocument(cells, Optional.empty(), "nometa.pdf", "nometa");
-
-        verify(documentService).save(argThat(d -> !d.isMetadataComplete()));
-    }
-
-    // ─── importSingleDocument — blank fields set to null ─────────────────────
-
-    @Test
-    void importSingleDocument_setsBlankFieldsToNull() {
-        when(documentService.findByOriginalFilename("blank.pdf")).thenReturn(Optional.empty());
-        when(documentService.save(any())).thenAnswer(inv -> inv.getArgument(0));
-
-        List<String> cells = buildCells("blank.pdf", "", "", "");
-        service.importSingleDocument(cells, Optional.empty(), "blank.pdf", "blank");
-
-        verify(documentService).save(argThat(d ->
-                d.getLocation() == null &&
-                d.getSummary() == null &&
-                d.getTranscription() == null &&
-                d.getArchiveBox() == null &&
-                d.getArchiveFolder() == null));
-    }
-
-    // ─── processRows — via ReflectionTestUtils ────────────────────────────────
-
-    @Test
-    void processRows_returnsZero_whenOnlyHeaderRow() {
-        List<List<String>> rows = List.of(List.of("header", "col1"));
-        MassImportService.ProcessResult result = ReflectionTestUtils.invokeMethod(service, "processRows", rows);
-        assertThat(result.processed()).isEqualTo(0);
-    }
-
-    @Test
-    void processRows_skipsRowWithBlankIndex() {
-        List<List<String>> rows = List.of(
-                List.of("header"),
-                minimalCells("")  // blank index
-        );
-        MassImportService.ProcessResult result = ReflectionTestUtils.invokeMethod(service, "processRows", rows);
-        assertThat(result.processed()).isEqualTo(0);
-        verify(documentService, never()).findByOriginalFilename(any());
-    }
-
-    @Test
-    void processRows_addsExtension_whenIndexHasNoDot() {
-        when(documentService.findByOriginalFilename("doc001.pdf")).thenReturn(Optional.empty());
-        when(documentService.save(any())).thenAnswer(inv -> inv.getArgument(0));
-
-        List<List<String>> rows = List.of(
-                List.of("header"),
-                minimalCells("doc001")  // no dot → appends ".pdf"
-        );
-        MassImportService.ProcessResult result = ReflectionTestUtils.invokeMethod(service, "processRows", rows);
-
-        assertThat(result.processed()).isEqualTo(1);
-        verify(documentService).findByOriginalFilename("doc001.pdf");
-    }
-
-    @Test
-    void processRows_usesFilenameAsIs_whenIndexHasDot() {
-        when(documentService.findByOriginalFilename("doc002.pdf")).thenReturn(Optional.empty());
-        when(documentService.save(any())).thenAnswer(inv -> inv.getArgument(0));
-
-        List<List<String>> rows = List.of(
-                List.of("header"),
-                minimalCells("doc002.pdf")  // has dot → used as-is
-        );
-        MassImportService.ProcessResult result = ReflectionTestUtils.invokeMethod(service, "processRows", rows);
-
-        assertThat(result.processed()).isEqualTo(1);
-        verify(documentService).findByOriginalFilename("doc002.pdf");
-    }
-
-    // ─── isValidImportFilename — security regression — do not remove ─────────
-
-    @Test
-    void isValidImportFilename_returnsFalse_whenFilenameIsNull() {
-        boolean result = ReflectionTestUtils.invokeMethod(service, "isValidImportFilename", (String) null);
-        assertThat(result).isFalse();
-    }
-
-    @Test
-    void isValidImportFilename_returnsFalse_whenFilenameIsBlank() {
-        boolean result = ReflectionTestUtils.invokeMethod(service, "isValidImportFilename", "   ");
-        assertThat(result).isFalse();
-    }
-
-    @Test
-    void isValidImportFilename_returnsFalse_whenFilenameContainsForwardSlash() {
-        boolean result = ReflectionTestUtils.invokeMethod(service, "isValidImportFilename", "etc/passwd");
-        assertThat(result).isFalse();
-    }
-
-    @Test
-    void isValidImportFilename_returnsFalse_whenFilenameContainsBackslash() {
-        boolean result = ReflectionTestUtils.invokeMethod(service, "isValidImportFilename", "..\\etc\\passwd");
-        assertThat(result).isFalse();
-    }
-
-    @Test
-    void isValidImportFilename_returnsFalse_whenFilenameContainsDotDot() {
-        boolean result = ReflectionTestUtils.invokeMethod(service, "isValidImportFilename", "doc..evil.pdf");
-        assertThat(result).isFalse();
-    }
-
-    @Test
-    void isValidImportFilename_returnsFalse_whenFilenameIsDotDot() {
-        boolean result = ReflectionTestUtils.invokeMethod(service, "isValidImportFilename", "..");
-        assertThat(result).isFalse();
-    }
-
-    @Test
-    void isValidImportFilename_returnsFalse_whenFilenameIsAbsolutePath() {
-        boolean result = ReflectionTestUtils.invokeMethod(service, "isValidImportFilename", "/etc/passwd");
-        assertThat(result).isFalse();
-    }
-
-    @Test
-    void isValidImportFilename_returnsFalse_whenFilenameContainsNullByte() {
-        boolean result = ReflectionTestUtils.invokeMethod(service, "isValidImportFilename", "file\0.pdf");
-        assertThat(result).isFalse();
-    }
-
-    @Test
-    void isValidImportFilename_returnsTrue_whenFilenameIsPlainBasename() {
-        boolean result = ReflectionTestUtils.invokeMethod(service, "isValidImportFilename", "document.pdf");
-        assertThat(result).isTrue();
-    }
-
-    @Test
-    void isValidImportFilename_returnsFalse_whenFilenameContainsUnicodeDivisionSlash() {
-        boolean result = ReflectionTestUtils.invokeMethod(service, "isValidImportFilename", "foo∕bar.pdf");
-        assertThat(result).isFalse();
-    }
-
-    @Test
-    void isValidImportFilename_returnsFalse_whenFilenameContainsFullwidthSlash() {
-        boolean result = ReflectionTestUtils.invokeMethod(service, "isValidImportFilename", "foo／bar.pdf");
-        assertThat(result).isFalse();
-    }
-
-    @Test
-    void isValidImportFilename_returnsFalse_whenFilenameContainsUnicodeReverseSolidus() {
-        boolean result = ReflectionTestUtils.invokeMethod(service, "isValidImportFilename", "foo⧵bar.pdf");
-        assertThat(result).isFalse();
-    }
-
-    @Test
-    void isValidImportFilename_returnsTrue_whenFilenameHasLeadingDot() {
-        boolean result = ReflectionTestUtils.invokeMethod(service, "isValidImportFilename", ".hidden.pdf");
-        assertThat(result).isTrue();
-    }
-
-    @Test
-    void isValidImportFilename_returnsTrue_whenFilenameHasSpaces() {
-        boolean result = ReflectionTestUtils.invokeMethod(service, "isValidImportFilename", "Brief an Oma.pdf");
-        assertThat(result).isTrue();
-    }
-
-    @Test
-    void processRows_skipsRowAndContinues_whenFilenameIsPathTraversal() {
-        when(documentService.findByOriginalFilename("legitimate.pdf")).thenReturn(Optional.empty());
-        when(documentService.save(any())).thenAnswer(inv -> inv.getArgument(0));
-
-        List<List<String>> rows = List.of(
-                List.of("header"),
-                minimalCells("../evil"),       // row 1: path traversal — should be skipped
-                minimalCells("legitimate.pdf") // row 2: valid — should be processed
-        );
-        MassImportService.ProcessResult result = ReflectionTestUtils.invokeMethod(service, "processRows", rows);
-
-        assertThat(result.processed()).isEqualTo(1);
-        assertThat(result.skippedFiles())
-                .extracting(MassImportService.SkippedFile::reason)
-                .containsExactly(MassImportService.SkipReason.INVALID_FILENAME_PATH_TRAVERSAL);
-    }
-
-    // ─── importSingleDocument — non-blank optional fields ────────────────────
-
-    @Test
-    void importSingleDocument_setsNonNullOptionalFields_whenPresent() {
-        when(documentService.findByOriginalFilename("rich.pdf")).thenReturn(Optional.empty());
-        when(documentService.save(any())).thenAnswer(inv -> inv.getArgument(0));
-
-        // box=1, folder=2, location=9, summary=11, transcription=13
-        List<String> cells = List.of(
-                "rich.pdf",      // 0: index
-                "Box A",         // 1: box
-                "Folder B",      // 2: folder
-                "",              // 3: sender
-                "",              // 4: unused
-                "",              // 5: receivers
-                "",              // 6: unused
-                "",              // 7: date
-                "",              // 8: unused
-                "Hamburg",       // 9: location
-                "",              // 10: tags
-                "A summary",     // 11: summary
-                "",              // 12: unused
-                "A transcript"   // 13: transcription
-        );
-
-        service.importSingleDocument(cells, Optional.empty(), "rich.pdf", "rich");
-
-        verify(documentService).save(argThat(d ->
-                "Box A".equals(d.getArchiveBox()) &&
-                "Folder B".equals(d.getArchiveFolder()) &&
-                "Hamburg".equals(d.getLocation()) &&
-                "A summary".equals(d.getSummary()) &&
-                "A transcript".equals(d.getTranscription())));
-    }
-
-    @Test
-    void importSingleDocument_setsMetadataComplete_whenReceiversArePresent() {
-        Person receiver = Person.builder().id(UUID.randomUUID()).firstName("Walter").lastName("Müller").build();
-        when(documentService.findByOriginalFilename("rcv.pdf")).thenReturn(Optional.empty());
-        when(documentService.save(any())).thenAnswer(inv -> inv.getArgument(0));
-        when(personService.findOrCreateByAlias("Walter Müller")).thenReturn(receiver);
-
-        List<String> cells = List.of(
-                "rcv.pdf", "", "", "", "", "Walter Müller", "", "", "", "", "", "", "", "");
-        service.importSingleDocument(cells, Optional.empty(), "rcv.pdf", "rcv");
-
-        verify(documentService).save(argThat(Document::isMetadataComplete));
-    }
-
-    @Test
-    void importSingleDocument_setsMetadataComplete_whenDateIsPresent() {
-        when(documentService.findByOriginalFilename("dated.pdf")).thenReturn(Optional.empty());
-        when(documentService.save(any())).thenAnswer(inv -> inv.getArgument(0));
-
-        List<String> cells = List.of(
-                "dated.pdf", "", "", "", "", "", "", "2024-03-15", "", "", "", "", "", "");
-        service.importSingleDocument(cells, Optional.empty(), "dated.pdf", "dated");
-
-        verify(documentService).save(argThat(Document::isMetadataComplete));
-    }
-
-    // ─── buildTitle — null location ───────────────────────────────────────────
-
-    @Test
-    void buildTitle_withNullLocation_skipsLocationPart() {
-        String result = ReflectionTestUtils.invokeMethod(service, "buildTitle",
-                "doc005", LocalDate.of(1940, 5, 1), (String) null);
-        assertThat(result).contains("doc005").contains("1940");
-        assertThat(result).doesNotContain("Berlin");
-    }
-
-    // ─── parseDate — via ReflectionTestUtils ─────────────────────────────────
-
-    @Test
-    void parseDate_returnsNull_whenValueIsNull() {
-        LocalDate result = ReflectionTestUtils.invokeMethod(service, "parseDate", (String) null);
-        assertThat(result).isNull();
-    }
-
-    @Test
-    void parseDate_returnsNull_whenValueIsBlank() {
-        LocalDate result = ReflectionTestUtils.invokeMethod(service, "parseDate", "   ");
-        assertThat(result).isNull();
-    }
-
-    @Test
-    void parseDate_returnsDate_whenValidIsoFormat() {
-        LocalDate result = ReflectionTestUtils.invokeMethod(service, "parseDate", "2024-03-15");
-        assertThat(result).isEqualTo(LocalDate.of(2024, 3, 15));
-    }
-
-    @Test
-    void parseDate_returnsNull_whenInvalidDateString() {
-        LocalDate result = ReflectionTestUtils.invokeMethod(service, "parseDate", "15.03.2024");
-        assertThat(result).isNull();
-    }
-
-    // ─── buildTitle — via ReflectionTestUtils ────────────────────────────────
-
-    @Test
-    void buildTitle_withDateAndLocation() {
-        String result = ReflectionTestUtils.invokeMethod(service, "buildTitle",
-                "doc001", LocalDate.of(1940, 5, 1), "Berlin");
-        assertThat(result).contains("doc001").contains("Berlin").contains("1940");
-    }
-
-    @Test
-    void buildTitle_withDateOnly() {
-        String result = ReflectionTestUtils.invokeMethod(service, "buildTitle",
-                "doc002", LocalDate.of(1960, 8, 15), "");
-        assertThat(result).contains("doc002").contains("1960");
-        assertThat(result).doesNotContain("Berlin");
-    }
-
-    @Test
-    void buildTitle_withIndexOnly_whenDateAndLocationAreNull() {
-        String result = ReflectionTestUtils.invokeMethod(service, "buildTitle",
-                "doc003", null, "");
-        assertThat(result).isEqualTo("doc003");
-    }
-
-    @Test
-    void buildTitle_withLocationOnly_whenDateIsNull() {
-        // date=null, location present → date part skipped, location appended
-        String result = ReflectionTestUtils.invokeMethod(service, "buildTitle",
-                "doc004", null, "Berlin");
-        assertThat(result).contains("doc004").contains("Berlin");
-        assertThat(result).doesNotContain("("); // no date part
-    }
-
-    // ─── getCell — via ReflectionTestUtils ───────────────────────────────────
-
-    @Test
-    void getCell_returnsEmptyString_whenColBeyondListSize() {
-        List<String> cells = List.of("a", "b");
-        String result = ReflectionTestUtils.invokeMethod(service, "getCell", cells, 5);
-        assertThat(result).isEmpty();
-    }
-
-    @Test
-    void getCell_returnsEmptyString_whenValueIsNull() {
-        List<String> cells = new ArrayList<>();
-        cells.add(null);
-        cells.add("b");
-        String result = ReflectionTestUtils.invokeMethod(service, "getCell", cells, 0);
-        assertThat(result).isEmpty();
-    }
-
-    @Test
-    void getCell_returnsTrimmedValue() {
-        List<String> cells = List.of("  hello  ", "world");
-        String result = ReflectionTestUtils.invokeMethod(service, "getCell", cells, 0);
-        assertThat(result).isEqualTo("hello");
-    }
-
-    // ─── PDF magic byte validation regression ─────────────────────────────────
-
-    @Test
-    void runImportAsync_uploadsValidPdf_andSkipsFakeOne(@TempDir Path tempDir) throws Exception {
-        setupOneValidOneFakeImport(tempDir);
-
-        service.runImportAsync();
-
-        verify(s3Client, times(1)).putObject(any(PutObjectRequest.class), any(RequestBody.class));
-    }
-
-    @Test
-    void runImportAsync_setsSkippedCount_toOne_whenOneFakeFile(@TempDir Path tempDir) throws Exception {
-        setupOneValidOneFakeImport(tempDir);
-
-        service.runImportAsync();
-
-        assertThat(service.getStatus().skipped()).isEqualTo(1);
-    }
-
-    @Test
-    void runImportAsync_includesRejectedFilename_inSkippedFiles(@TempDir Path tempDir) throws Exception {
-        setupOneValidOneFakeImport(tempDir);
-
-        service.runImportAsync();
-
-        assertThat(service.getStatus().skippedFiles())
-                .extracting(MassImportService.SkippedFile::filename)
-                .contains("fake.pdf");
-    }
-
-    @Test
-    void runImportAsync_skipsFile_whenShorterThanFourBytes(@TempDir Path tempDir) throws Exception {
-        Files.write(tempDir.resolve("tiny.pdf"), new byte[]{0x25, 0x50, 0x44}); // only 3 bytes
-        buildMinimalImportXlsx(tempDir, "tiny.pdf");
-        ReflectionTestUtils.setField(service, "importDir", tempDir.toString());
-        lenient().when(documentService.findByOriginalFilename(any())).thenReturn(Optional.empty());
-
-        service.runImportAsync();
-
-        assertThat(service.getStatus().skipped()).isEqualTo(1);
-    }
-
-    @Test
-    void runImportAsync_skipsFile_whenMagicBytesCheckThrowsIOException(@TempDir Path tempDir) throws Exception {
-        Files.writeString(tempDir.resolve("unreadable.pdf"), "some content");
-        buildMinimalImportXlsx(tempDir, "unreadable.pdf");
-        ReflectionTestUtils.setField(service, "importDir", tempDir.toString());
-        lenient().when(documentService.findByOriginalFilename(any())).thenReturn(Optional.empty());
-
-        MassImportService spyService = spy(service);
-        doThrow(new java.io.IOException("simulated read error")).when(spyService).openFileStream(any(File.class));
-
-        spyService.runImportAsync();
-
-        assertThat(spyService.getStatus().skipped()).isEqualTo(1);
-        assertThat(spyService.getStatus().skippedFiles())
-                .extracting(MassImportService.SkippedFile::reason)
-                .containsExactly(MassImportService.SkipReason.FILE_READ_ERROR);
-    }
-
-    // ─── findFileRecursive — symlink escape security regression — do not remove ─
-
-    @Test
-    void findFileRecursive_throwsDomainException_whenSymlinkEscapesImportDir(
-            @TempDir Path importDirPath, @TempDir Path outsideDir) throws Exception {
-        Path outsideFile = outsideDir.resolve("secret.pdf");
-        Files.writeString(outsideFile, "sensitive content");
-        Files.createSymbolicLink(importDirPath.resolve("secret.pdf"), outsideFile);
-
-        ReflectionTestUtils.setField(service, "importDir", importDirPath.toString());
-
-        assertThatThrownBy(() -> ReflectionTestUtils.invokeMethod(service, "findFileRecursive", "secret.pdf"))
-                .isInstanceOf(DomainException.class);
-    }
-
-    // ─── readOds — XXE security regression ───────────────────────────────────
-
-    // Security regression — do not remove.
-    @Test
-    void readOds_rejects_xxe_doctype_payload(@TempDir Path tempDir) throws Exception {
-        File malicious = buildXxeOds(tempDir, "file:///etc/hostname");
-        assertThatThrownBy(() -> service.readOds(malicious))
-                .isInstanceOf(SAXParseException.class)
-                .hasMessageContaining("DOCTYPE is disallowed");
-    }
-
-    @Test
-    void readOds_parses_valid_ods_correctly(@TempDir Path tempDir) throws Exception {
-        File valid = buildValidOds(tempDir, "Mustermann");
-        List<List<String>> rows = service.readOds(valid);
-        assertThat(rows).isNotEmpty();
-        assertThat(rows.get(0)).contains("Mustermann");
-    }
-
-    // ─── helpers ──────────────────────────────────────────────────────────────
-
-    /**
-     * Builds a minimal 14-element cell row with the given filename at index 0
-     * and blanks for all optional fields.
-     */
-    private List<String> minimalCells(String filename) {
-        return buildCells(filename, "", "", "");
-    }
-
-    /**
-     * Builds a cell row with sender, receiver, and tag controls.
-     * Layout matches the default column indices set in setUp().
-     */
-    private List<String> buildCells(String filename, String sender, String receivers, String tag) {
-        // 14 elements: index=0,box=1,folder=2,sender=3,[4],receivers=5,[6],date=7,[8],location=9,tag=10,summary=11,[12],transcription=13
-        return List.of(
-                filename,  // 0: index
-                "",        // 1: box
-                "",        // 2: folder
-                sender,    // 3: sender
-                "",        // 4: (unused)
-                receivers, // 5: receivers
-                "",        // 6: (unused)
-                "",        // 7: date
-                "",        // 8: (unused)
-                "",        // 9: location
-                tag,       // 10: tags
-                "",        // 11: summary
-                "",        // 12: (unused)
-                ""         // 13: transcription
-        );
-    }
-
-    /** Creates a minimal ODS ZIP containing a content.xml with an XXE payload. */
-    private File buildXxeOds(Path dir, String entityTarget) throws Exception {
-        String xml = "<?xml version=\"1.0\"?>"
-                + "<!DOCTYPE foo [<!ENTITY xxe SYSTEM \"" + entityTarget + "\">]>"
-                + "<office:document-content"
-                + " xmlns:office=\"urn:oasis:names:tc:opendocument:xmlns:office:1.0\""
-                + " xmlns:table=\"urn:oasis:names:tc:opendocument:xmlns:table:1.0\""
-                + " xmlns:text=\"urn:oasis:names:tc:opendocument:xmlns:text:1.0\">"
-                + "<office:body><office:spreadsheet>"
-                + "<table:table><table:table-row><table:table-cell>"
-                + "<text:p>&xxe;</text:p>"
-                + "</table:table-cell></table:table-row></table:table>"
-                + "</office:spreadsheet></office:body>"
-                + "</office:document-content>";
-        return writeOdsZip(dir.resolve("malicious.ods"), xml);
-    }
-
-    /** Creates a minimal valid ODS ZIP containing a content.xml with the given cell value.
-     *  cellValue must not contain XML metacharacters ({@code < > &}). */
-    private File buildValidOds(Path dir, String cellValue) throws Exception {
-        String xml = "<?xml version=\"1.0\"?>"
-                + "<office:document-content"
-                + " xmlns:office=\"urn:oasis:names:tc:opendocument:xmlns:office:1.0\""
-                + " xmlns:table=\"urn:oasis:names:tc:opendocument:xmlns:table:1.0\""
-                + " xmlns:text=\"urn:oasis:names:tc:opendocument:xmlns:text:1.0\">"
-                + "<office:body><office:spreadsheet>"
-                + "<table:table><table:table-row><table:table-cell>"
-                + "<text:p>" + cellValue + "</text:p>"
-                + "</table:table-cell></table:table-row></table:table>"
-                + "</office:spreadsheet></office:body>"
-                + "</office:document-content>";
-        return writeOdsZip(dir.resolve("valid.ods"), xml);
-    }
-
-    private File writeOdsZip(Path destination, String contentXml) throws Exception {
-        try (OutputStream fos = Files.newOutputStream(destination);
-             ZipOutputStream zip = new ZipOutputStream(fos)) {
-            zip.putNextEntry(new ZipEntry("content.xml"));
-            zip.write(contentXml.getBytes(StandardCharsets.UTF_8));
-            zip.closeEntry();
-        }
-        return destination.toFile();
-    }
-
-    private void setupOneValidOneFakeImport(Path tempDir) throws Exception {
-        byte[] pdfHeader = {0x25, 0x50, 0x44, 0x46, 0x2D}; // %PDF-
-        Files.write(tempDir.resolve("real.pdf"), pdfHeader);
-        Files.writeString(tempDir.resolve("fake.pdf"), "not a pdf");
-        buildMinimalImportXlsx(tempDir, "real.pdf", "fake.pdf");
-        ReflectionTestUtils.setField(service, "importDir", tempDir.toString());
-        when(documentService.findByOriginalFilename(any())).thenReturn(Optional.empty());
-        when(documentService.save(any())).thenAnswer(inv -> inv.getArgument(0));
-    }
-
-    private void buildMinimalImportXlsx(Path dir, String... filenames) throws Exception {
-        Path xlsx = dir.resolve("import.xlsx");
-        try (XSSFWorkbook wb = new XSSFWorkbook()) {
-            org.apache.poi.ss.usermodel.Sheet sheet = wb.createSheet("Sheet1");
-            sheet.createRow(0).createCell(0).setCellValue("Index");
-            for (int i = 0; i < filenames.length; i++) {
-                sheet.createRow(i + 1).createCell(0).setCellValue(filenames[i]);
-            }
-            try (OutputStream out = Files.newOutputStream(xlsx)) {
-                wb.write(out);
-            }
-        }
-    }
-}
diff --git a/backend/src/test/java/org/raddatz/familienarchiv/importing/PersonRegisterImporterTest.java b/backend/src/test/java/org/raddatz/familienarchiv/importing/PersonRegisterImporterTest.java
new file mode 100644
index 00000000..af5740c0
--- /dev/null
+++ b/backend/src/test/java/org/raddatz/familienarchiv/importing/PersonRegisterImporterTest.java
@@ -0,0 +1,130 @@
+package org.raddatz.familienarchiv.importing;
+
+import org.apache.poi.ss.usermodel.Row;
+import org.apache.poi.ss.usermodel.Sheet;
+import org.apache.poi.xssf.usermodel.XSSFWorkbook;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.junit.jupiter.api.io.TempDir;
+import org.mockito.ArgumentCaptor;
+import org.mockito.junit.jupiter.MockitoExtension;
+import org.raddatz.familienarchiv.person.Person;
+import org.raddatz.familienarchiv.person.PersonService;
+import org.raddatz.familienarchiv.person.PersonUpsertCommand;
+
+import java.io.OutputStream;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.UUID;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+@ExtendWith(MockitoExtension.class)
+class PersonRegisterImporterTest {
+
+    @Test
+    void load_upsertsPersonBySourceRef_withProvisionalFalse(@TempDir Path tempDir) throws Exception {
+        PersonService personService = mock(PersonService.class);
+        when(personService.upsertBySourceRef(any())).thenAnswer(inv -> personOf(inv.getArgument(0)));
+        Path xlsx = writePersons(tempDir, row(
+                "allemeyer-elsgard", "Allemeyer", "Elsgard", "Wöhler", "Nichte von Herbert", "False"));
+
+        new PersonRegisterImporter(personService).load(xlsx.toFile());
+
+        ArgumentCaptor<PersonUpsertCommand> captor = ArgumentCaptor.forClass(PersonUpsertCommand.class);
+        verify(personService).upsertBySourceRef(captor.capture());
+        PersonUpsertCommand cmd = captor.getValue();
+        assertThat(cmd.sourceRef()).isEqualTo("allemeyer-elsgard");
+        assertThat(cmd.lastName()).isEqualTo("Allemeyer");
+        assertThat(cmd.firstName()).isEqualTo("Elsgard");
+        assertThat(cmd.maidenName()).isEqualTo("Wöhler");
+        assertThat(cmd.notes()).isEqualTo("Nichte von Herbert");
+        assertThat(cmd.provisional()).isFalse();
+    }
+
+    @Test
+    void load_parsesCapitalisedPythonBool_True(@TempDir Path tempDir) throws Exception {
+        PersonService personService = mock(PersonService.class);
+        when(personService.upsertBySourceRef(any())).thenAnswer(inv -> personOf(inv.getArgument(0)));
+        Path xlsx = writePersons(tempDir, row(
+                "noise-geschirr", "Geschirr", "", "", "", "True"));
+
+        new PersonRegisterImporter(personService).load(xlsx.toFile());
+
+        ArgumentCaptor<PersonUpsertCommand> captor = ArgumentCaptor.forClass(PersonUpsertCommand.class);
+        verify(personService).upsertBySourceRef(captor.capture());
+        assertThat(captor.getValue().provisional()).isTrue();
+    }
+
+    @Test
+    void load_skipsRowWithBlankPersonId(@TempDir Path tempDir) throws Exception {
+        PersonService personService = mock(PersonService.class);
+        Path xlsx = writePersons(tempDir, row("", "NoId", "", "", "", "False"));
+
+        new PersonRegisterImporter(personService).load(xlsx.toFile());
+
+        verify(personService, times(0)).upsertBySourceRef(any());
+    }
+
+    @Test
+    void load_returnsCountOfProcessedRows(@TempDir Path tempDir) throws Exception {
+        PersonService personService = mock(PersonService.class);
+        when(personService.upsertBySourceRef(any())).thenAnswer(inv -> personOf(inv.getArgument(0)));
+        Path xlsx = writePersons(tempDir,
+                row("a-one", "One", "A", "", "", "False"),
+                row("a-two", "Two", "B", "", "", "False"));
+
+        int processed = new PersonRegisterImporter(personService).load(xlsx.toFile());
+
+        assertThat(processed).isEqualTo(2);
+    }
+
+    private static Person personOf(PersonUpsertCommand cmd) {
+        return Person.builder().id(UUID.randomUUID()).sourceRef(cmd.sourceRef())
+                .firstName(cmd.firstName()).lastName(cmd.lastName())
+                .provisional(cmd.provisional()).build();
+    }
+
+    private Map<String, String> row(String personId, String lastName, String firstName,
+                                    String maidenName, String notes, String provisional) {
+        Map<String, String> r = new LinkedHashMap<>();
+        r.put("person_id", personId);
+        r.put("last_name", lastName);
+        r.put("first_name", firstName);
+        r.put("maiden_name", maidenName);
+        r.put("notes", notes);
+        r.put("provisional", provisional);
+        return r;
+    }
+
+    @SafeVarargs
+    private Path writePersons(Path dir, Map<String, String>... rows) throws Exception {
+        Path xlsx = dir.resolve("canonical-persons.xlsx");
+        List<String> headers = List.of("person_id", "last_name", "first_name", "maiden_name", "notes", "provisional");
+        try (XSSFWorkbook wb = new XSSFWorkbook()) {
+            Sheet sheet = wb.createSheet("Sheet1");
+            Row header = sheet.createRow(0);
+            for (int i = 0; i < headers.size(); i++) {
+                header.createCell(i).setCellValue(headers.get(i));
+            }
+            for (int r = 0; r < rows.length; r++) {
+                Row row = sheet.createRow(r + 1);
+                for (int c = 0; c < headers.size(); c++) {
+                    row.createCell(c).setCellValue(rows[r].getOrDefault(headers.get(c), ""));
+                }
+            }
+            try (OutputStream out = Files.newOutputStream(xlsx)) {
+                wb.write(out);
+            }
+        }
+        return xlsx;
+    }
+}
diff --git a/backend/src/test/java/org/raddatz/familienarchiv/importing/PersonTreeImporterTest.java b/backend/src/test/java/org/raddatz/familienarchiv/importing/PersonTreeImporterTest.java
new file mode 100644
index 00000000..ce90d260
--- /dev/null
+++ b/backend/src/test/java/org/raddatz/familienarchiv/importing/PersonTreeImporterTest.java
@@ -0,0 +1,163 @@
+package org.raddatz.familienarchiv.importing;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.junit.jupiter.api.io.TempDir;
+import org.mockito.ArgumentCaptor;
+import org.mockito.junit.jupiter.MockitoExtension;
+import org.raddatz.familienarchiv.exception.DomainException;
+import org.raddatz.familienarchiv.exception.ErrorCode;
+import org.raddatz.familienarchiv.person.Person;
+import org.raddatz.familienarchiv.person.PersonService;
+import org.raddatz.familienarchiv.person.PersonUpsertCommand;
+import org.raddatz.familienarchiv.person.relationship.RelationType;
+import org.raddatz.familienarchiv.person.relationship.RelationshipService;
+import org.raddatz.familienarchiv.person.relationship.dto.CreateRelationshipRequest;
+
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.UUID;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.ArgumentMatchers.eq;
+import static org.mockito.Mockito.doThrow;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+@ExtendWith(MockitoExtension.class)
+class PersonTreeImporterTest {
+
+    @Test
+    void load_upsertsTreePersonBySourceRef_withFamilyMemberFlag(@TempDir Path tempDir) throws Exception {
+        PersonService personService = mock(PersonService.class);
+        RelationshipService relationshipService = mock(RelationshipService.class);
+        when(personService.upsertBySourceRef(any())).thenAnswer(inv -> personOf(inv.getArgument(0)));
+        Path json = write(tempDir, """
+                {"persons":[
+                  {"rowId":"row_002","firstName":"Elsgard","lastName":"Allemeyer","maidenName":"Wöhler",
+                   "notes":"Nichte","birthYear":1920,"deathYear":1999,"familyMember":true,"personId":"allemeyer-elsgard"}
+                ],"relationships":[]}
+                """);
+
+        new PersonTreeImporter(personService, relationshipService)
+                .load(json.toFile());
+
+        ArgumentCaptor<PersonUpsertCommand> captor = ArgumentCaptor.forClass(PersonUpsertCommand.class);
+        verify(personService).upsertBySourceRef(captor.capture());
+        PersonUpsertCommand cmd = captor.getValue();
+        assertThat(cmd.sourceRef()).isEqualTo("allemeyer-elsgard");
+        assertThat(cmd.familyMember()).isTrue();
+        assertThat(cmd.provisional()).isFalse();
+    }
+
+    @Test
+    void load_createsRelationship_resolvingRowIdsToUpsertedPersons(@TempDir Path tempDir) throws Exception {
+        PersonService personService = mock(PersonService.class);
+        RelationshipService relationshipService = mock(RelationshipService.class);
+        UUID idA = UUID.randomUUID();
+        UUID idB = UUID.randomUUID();
+        when(personService.upsertBySourceRef(any())).thenAnswer(inv -> {
+            PersonUpsertCommand c = inv.getArgument(0);
+            return Person.builder().id(c.sourceRef().equals("a") ? idA : idB)
+                    .sourceRef(c.sourceRef()).lastName(c.lastName()).build();
+        });
+        Path json = write(tempDir, """
+                {"persons":[
+                  {"rowId":"row_a","lastName":"A","familyMember":true,"personId":"a"},
+                  {"rowId":"row_b","lastName":"B","familyMember":true,"personId":"b"}
+                ],"relationships":[
+                  {"personId":"row_a","relatedPersonId":"row_b","type":"SPOUSE_OF","source":"verheiratet_mit"}
+                ]}
+                """);
+
+        new PersonTreeImporter(personService, relationshipService)
+                .load(json.toFile());
+
+        ArgumentCaptor<CreateRelationshipRequest> captor = ArgumentCaptor.forClass(CreateRelationshipRequest.class);
+        verify(relationshipService).addRelationship(eq(idA), captor.capture());
+        assertThat(captor.getValue().relatedPersonId()).isEqualTo(idB);
+        assertThat(captor.getValue().relationType()).isEqualTo(RelationType.SPOUSE_OF);
+    }
+
+    @Test
+    void load_swallowsDuplicateRelationship_forIdempotentReimport(@TempDir Path tempDir) throws Exception {
+        PersonService personService = mock(PersonService.class);
+        RelationshipService relationshipService = mock(RelationshipService.class);
+        when(personService.upsertBySourceRef(any()))
+                .thenAnswer(inv -> personOf(inv.getArgument(0)));
+        doThrow(DomainException.conflict(ErrorCode.DUPLICATE_RELATIONSHIP, "exists"))
+                .when(relationshipService).addRelationship(any(), any());
+        Path json = write(tempDir, """
+                {"persons":[
+                  {"rowId":"row_a","lastName":"A","familyMember":true,"personId":"a"},
+                  {"rowId":"row_b","lastName":"B","familyMember":true,"personId":"b"}
+                ],"relationships":[
+                  {"personId":"row_a","relatedPersonId":"row_b","type":"SPOUSE_OF","source":"verheiratet_mit"}
+                ]}
+                """);
+
+        PersonTreeImporter importer = new PersonTreeImporter(personService, relationshipService);
+
+        // Must not propagate the conflict — re-import is idempotent.
+        importer.load(json.toFile());
+
+        verify(relationshipService).addRelationship(any(), any());
+    }
+
+    @Test
+    void load_propagatesUnexpectedDomainException_fromAddRelationship(@TempDir Path tempDir) throws Exception {
+        PersonService personService = mock(PersonService.class);
+        RelationshipService relationshipService = mock(RelationshipService.class);
+        when(personService.upsertBySourceRef(any()))
+                .thenAnswer(inv -> personOf(inv.getArgument(0)));
+        // An unexpected ErrorCode (not DUPLICATE/CIRCULAR) must NOT be swallowed.
+        doThrow(DomainException.internal(ErrorCode.INTERNAL_ERROR, "boom"))
+                .when(relationshipService).addRelationship(any(), any());
+        Path json = write(tempDir, """
+                {"persons":[
+                  {"rowId":"row_a","lastName":"A","familyMember":true,"personId":"a"},
+                  {"rowId":"row_b","lastName":"B","familyMember":true,"personId":"b"}
+                ],"relationships":[
+                  {"personId":"row_a","relatedPersonId":"row_b","type":"SPOUSE_OF","source":"verheiratet_mit"}
+                ]}
+                """);
+
+        PersonTreeImporter importer = new PersonTreeImporter(personService, relationshipService);
+
+        assertThatThrownBy(() -> importer.load(json.toFile()))
+                .isInstanceOf(DomainException.class)
+                .extracting("code").isEqualTo(ErrorCode.INTERNAL_ERROR);
+    }
+
+    @Test
+    void load_skipsRelationship_whenRowIdUnresolved(@TempDir Path tempDir) throws Exception {
+        PersonService personService = mock(PersonService.class);
+        RelationshipService relationshipService = mock(RelationshipService.class);
+        when(personService.upsertBySourceRef(any())).thenAnswer(inv -> personOf(inv.getArgument(0)));
+        Path json = write(tempDir, """
+                {"persons":[
+                  {"rowId":"row_a","lastName":"A","familyMember":true,"personId":"a"}
+                ],"relationships":[
+                  {"personId":"row_a","relatedPersonId":"row_ghost","type":"SPOUSE_OF","source":"x"}
+                ]}
+                """);
+
+        new PersonTreeImporter(personService, relationshipService)
+                .load(json.toFile());
+
+        verify(relationshipService, org.mockito.Mockito.never()).addRelationship(any(), any());
+    }
+
+    private static Person personOf(PersonUpsertCommand cmd) {
+        return Person.builder().id(UUID.randomUUID()).sourceRef(cmd.sourceRef()).lastName(cmd.lastName()).build();
+    }
+
+    private Path write(Path dir, String json) throws Exception {
+        Path file = dir.resolve("canonical-persons-tree.json");
+        Files.writeString(file, json);
+        return file;
+    }
+}
diff --git a/backend/src/test/java/org/raddatz/familienarchiv/importing/TagTreeImporterTest.java b/backend/src/test/java/org/raddatz/familienarchiv/importing/TagTreeImporterTest.java
new file mode 100644
index 00000000..e6becae5
--- /dev/null
+++ b/backend/src/test/java/org/raddatz/familienarchiv/importing/TagTreeImporterTest.java
@@ -0,0 +1,103 @@
+package org.raddatz.familienarchiv.importing;
+
+import org.apache.poi.ss.usermodel.Row;
+import org.apache.poi.ss.usermodel.Sheet;
+import org.apache.poi.xssf.usermodel.XSSFWorkbook;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.junit.jupiter.api.io.TempDir;
+import org.mockito.junit.jupiter.MockitoExtension;
+import org.raddatz.familienarchiv.tag.Tag;
+import org.raddatz.familienarchiv.tag.TagService;
+
+import java.io.OutputStream;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.List;
+import java.util.UUID;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.ArgumentMatchers.eq;
+import static org.mockito.ArgumentMatchers.isNull;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+@ExtendWith(MockitoExtension.class)
+class TagTreeImporterTest {
+
+    @Test
+    void load_upsertsRootTagWithNullParent(@TempDir Path tempDir) throws Exception {
+        TagService tagService = mock(TagService.class);
+        when(tagService.upsertBySourceRef(any(), any(), any()))
+                .thenAnswer(inv -> tagOf(inv.getArgument(0), inv.getArgument(1), inv.getArgument(2)));
+        Path xlsx = writeTagTree(tempDir, List.<String[]>of(
+                new String[]{"Themen", "", "Themen"}));
+
+        new TagTreeImporter(tagService).load(xlsx.toFile());
+
+        verify(tagService).upsertBySourceRef("Themen", "Themen", null);
+    }
+
+    @Test
+    void load_resolvesParentByPath_forChildTag(@TempDir Path tempDir) throws Exception {
+        TagService tagService = mock(TagService.class);
+        UUID rootId = UUID.randomUUID();
+        when(tagService.upsertBySourceRef(eq("Themen"), eq("Themen"), isNull()))
+                .thenReturn(tagOf("Themen", "Themen", null, rootId));
+        when(tagService.upsertBySourceRef(eq("Themen/Brautbriefe"), eq("Brautbriefe"), eq(rootId)))
+                .thenReturn(tagOf("Themen/Brautbriefe", "Brautbriefe", rootId));
+        Path xlsx = writeTagTree(tempDir, List.<String[]>of(
+                new String[]{"Themen", "", "Themen"},
+                new String[]{"Themen/Brautbriefe", "Themen", "Brautbriefe"}));
+
+        new TagTreeImporter(tagService).load(xlsx.toFile());
+
+        verify(tagService).upsertBySourceRef("Themen/Brautbriefe", "Brautbriefe", rootId);
+    }
+
+    @Test
+    void load_returnsCountOfProcessedRows(@TempDir Path tempDir) throws Exception {
+        TagService tagService = mock(TagService.class);
+        when(tagService.upsertBySourceRef(any(), any(), any()))
+                .thenAnswer(inv -> tagOf(inv.getArgument(0), inv.getArgument(1), inv.getArgument(2)));
+        Path xlsx = writeTagTree(tempDir, List.<String[]>of(
+                new String[]{"Themen", "", "Themen"},
+                new String[]{"Themen/Brautbriefe", "Themen", "Brautbriefe"}));
+
+        int processed = new TagTreeImporter(tagService).load(xlsx.toFile());
+
+        assertThat(processed).isEqualTo(2);
+    }
+
+    private static Tag tagOf(String sourceRef, String name, UUID parentId) {
+        return tagOf(sourceRef, name, parentId, UUID.randomUUID());
+    }
+
+    private static Tag tagOf(String sourceRef, String name, UUID parentId, UUID id) {
+        return Tag.builder().id(id).sourceRef(sourceRef).name(name).parentId(parentId).build();
+    }
+
+    private Path writeTagTree(Path dir, List<String[]> rows) throws Exception {
+        Path xlsx = dir.resolve("canonical-tag-tree.xlsx");
+        try (XSSFWorkbook wb = new XSSFWorkbook()) {
+            Sheet sheet = wb.createSheet("Sheet1");
+            Row header = sheet.createRow(0);
+            header.createCell(0).setCellValue("tag_path");
+            header.createCell(1).setCellValue("parent_name");
+            header.createCell(2).setCellValue("tag_name");
+            for (int r = 0; r < rows.size(); r++) {
+                Row row = sheet.createRow(r + 1);
+                String[] values = rows.get(r);
+                for (int c = 0; c < values.length; c++) {
+                    row.createCell(c).setCellValue(values[c]);
+                }
+            }
+            try (OutputStream out = Files.newOutputStream(xlsx)) {
+                wb.write(out);
+            }
+        }
+        return xlsx;
+    }
+}
diff --git a/backend/src/test/java/org/raddatz/familienarchiv/person/PersonImportUpsertTest.java b/backend/src/test/java/org/raddatz/familienarchiv/person/PersonImportUpsertTest.java
new file mode 100644
index 00000000..c8b81b2b
--- /dev/null
+++ b/backend/src/test/java/org/raddatz/familienarchiv/person/PersonImportUpsertTest.java
@@ -0,0 +1,151 @@
+package org.raddatz.familienarchiv.person;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.InjectMocks;
+import org.mockito.Mock;
+import org.mockito.junit.jupiter.MockitoExtension;
+
+import java.util.Optional;
+import java.util.UUID;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.ArgumentMatchers.argThat;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+@ExtendWith(MockitoExtension.class)
+class PersonImportUpsertTest {
+
+    @Mock PersonRepository personRepository;
+    @Mock PersonNameAliasRepository aliasRepository;
+    @InjectMocks PersonService personService;
+
+    @Test
+    void upsertBySourceRef_insertsNewPerson_whenSourceRefUnknown() {
+        when(personRepository.findBySourceRef("clara-cram")).thenReturn(Optional.empty());
+        when(personRepository.save(any())).thenAnswer(inv -> inv.getArgument(0));
+
+        PersonUpsertCommand cmd = PersonUpsertCommand.builder()
+                .sourceRef("clara-cram").firstName("Clara").lastName("Cram")
+                .personType(PersonType.PERSON).provisional(false).build();
+
+        Person result = personService.upsertBySourceRef(cmd);
+
+        assertThat(result.getSourceRef()).isEqualTo("clara-cram");
+        assertThat(result.getFirstName()).isEqualTo("Clara");
+        assertThat(result.getLastName()).isEqualTo("Cram");
+        assertThat(result.isProvisional()).isFalse();
+    }
+
+    @Test
+    void upsertBySourceRef_updatesInPlace_whenSourceRefExists() {
+        Person existing = Person.builder()
+                .id(UUID.randomUUID()).sourceRef("clara-cram")
+                .firstName("Clara").lastName("Cram").build();
+        when(personRepository.findBySourceRef("clara-cram")).thenReturn(Optional.of(existing));
+        when(personRepository.save(any())).thenAnswer(inv -> inv.getArgument(0));
+
+        PersonUpsertCommand cmd = PersonUpsertCommand.builder()
+                .sourceRef("clara-cram").firstName("Clara").lastName("Cram")
+                .notes("Updated note").personType(PersonType.PERSON).provisional(false).build();
+
+        personService.upsertBySourceRef(cmd);
+
+        verify(personRepository).save(argThat(p -> p.getId().equals(existing.getId())));
+        verify(personRepository, never()).save(argThat(p -> p.getId() == null));
+    }
+
+    @Test
+    void upsertBySourceRef_preservesHumanEditedNonBlankFields() {
+        // A human renamed the maiden-name register person and added notes in-app.
+        Person humanEdited = Person.builder()
+                .id(UUID.randomUUID()).sourceRef("clara-cram")
+                .firstName("Klara").lastName("Cram-Müller").notes("Verified by Marcel").build();
+        when(personRepository.findBySourceRef("clara-cram")).thenReturn(Optional.of(humanEdited));
+        when(personRepository.save(any())).thenAnswer(inv -> inv.getArgument(0));
+
+        PersonUpsertCommand cmd = PersonUpsertCommand.builder()
+                .sourceRef("clara-cram").firstName("Clara").lastName("Cram")
+                .notes("Auto note").personType(PersonType.PERSON).provisional(false).build();
+
+        Person result = personService.upsertBySourceRef(cmd);
+
+        // Human edits survive the re-import.
+        assertThat(result.getFirstName()).isEqualTo("Klara");
+        assertThat(result.getLastName()).isEqualTo("Cram-Müller");
+        assertThat(result.getNotes()).isEqualTo("Verified by Marcel");
+    }
+
+    @Test
+    void upsertBySourceRef_fillsOnlyBlankFields_onReimport() {
+        Person existing = Person.builder()
+                .id(UUID.randomUUID()).sourceRef("clara-cram")
+                .firstName("Clara").lastName("Cram").notes(null).build();
+        when(personRepository.findBySourceRef("clara-cram")).thenReturn(Optional.of(existing));
+        when(personRepository.save(any())).thenAnswer(inv -> inv.getArgument(0));
+
+        PersonUpsertCommand cmd = PersonUpsertCommand.builder()
+                .sourceRef("clara-cram").firstName("Clara").lastName("Cram")
+                .notes("Nichte von Herbert").personType(PersonType.PERSON).provisional(false).build();
+
+        Person result = personService.upsertBySourceRef(cmd);
+
+        // Blank field gets filled by canonical value.
+        assertThat(result.getNotes()).isEqualTo("Nichte von Herbert");
+    }
+
+    @Test
+    void upsertBySourceRef_fillsBlankYears_butPreservesHumanEditedYears_onReimport() {
+        // Existing has a human-set birthYear and a blank deathYear.
+        Person existing = Person.builder()
+                .id(UUID.randomUUID()).sourceRef("clara-cram")
+                .lastName("Cram").birthYear(1890).deathYear(null).build();
+        when(personRepository.findBySourceRef("clara-cram")).thenReturn(Optional.of(existing));
+        when(personRepository.save(any())).thenAnswer(inv -> inv.getArgument(0));
+
+        PersonUpsertCommand cmd = PersonUpsertCommand.builder()
+                .sourceRef("clara-cram").lastName("Cram")
+                .birthYear(1888).deathYear(1965)
+                .personType(PersonType.PERSON).provisional(false).build();
+
+        Person result = personService.upsertBySourceRef(cmd);
+
+        assertThat(result.getBirthYear()).isEqualTo(1890); // human value kept
+        assertThat(result.getDeathYear()).isEqualTo(1965); // blank filled from canonical
+    }
+
+    @Test
+    void upsertBySourceRef_neverFlipsProvisionalBackToTrue_onceHumanConfirmed() {
+        // A human confirmed this provisional importer-created person (provisional -> false).
+        Person confirmed = Person.builder()
+                .id(UUID.randomUUID()).sourceRef("schwester-hanni")
+                .firstName(null).lastName("Schwester Hanni").provisional(false).build();
+        when(personRepository.findBySourceRef("schwester-hanni")).thenReturn(Optional.of(confirmed));
+        when(personRepository.save(any())).thenAnswer(inv -> inv.getArgument(0));
+
+        PersonUpsertCommand cmd = PersonUpsertCommand.builder()
+                .sourceRef("schwester-hanni").lastName("Schwester Hanni")
+                .personType(PersonType.PERSON).provisional(true).build();
+
+        Person result = personService.upsertBySourceRef(cmd);
+
+        assertThat(result.isProvisional()).isFalse();
+    }
+
+    @Test
+    void upsertBySourceRef_setsProvisionalTrue_forNewProvisionalPerson() {
+        when(personRepository.findBySourceRef("noise-geschirr")).thenReturn(Optional.empty());
+        when(personRepository.save(any())).thenAnswer(inv -> inv.getArgument(0));
+
+        PersonUpsertCommand cmd = PersonUpsertCommand.builder()
+                .sourceRef("noise-geschirr").lastName("Tante Tüten")
+                .personType(PersonType.PERSON).provisional(true).build();
+
+        Person result = personService.upsertBySourceRef(cmd);
+
+        assertThat(result.isProvisional()).isTrue();
+    }
+}
diff --git a/backend/src/test/java/org/raddatz/familienarchiv/tag/TagImportUpsertTest.java b/backend/src/test/java/org/raddatz/familienarchiv/tag/TagImportUpsertTest.java
new file mode 100644
index 00000000..c2e29dc0
--- /dev/null
+++ b/backend/src/test/java/org/raddatz/familienarchiv/tag/TagImportUpsertTest.java
@@ -0,0 +1,62 @@
+package org.raddatz.familienarchiv.tag;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.InjectMocks;
+import org.mockito.Mock;
+import org.mockito.junit.jupiter.MockitoExtension;
+
+import java.util.Optional;
+import java.util.UUID;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.ArgumentMatchers.argThat;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+@ExtendWith(MockitoExtension.class)
+class TagImportUpsertTest {
+
+    @Mock TagRepository tagRepository;
+    @InjectMocks TagService tagService;
+
+    @Test
+    void upsertBySourceRef_insertsNewTag_whenSourceRefUnknown() {
+        when(tagRepository.findBySourceRef("Themen/Brautbriefe")).thenReturn(Optional.empty());
+        when(tagRepository.save(any())).thenAnswer(inv -> inv.getArgument(0));
+
+        UUID parentId = UUID.randomUUID();
+        Tag result = tagService.upsertBySourceRef("Themen/Brautbriefe", "Brautbriefe", parentId);
+
+        assertThat(result.getSourceRef()).isEqualTo("Themen/Brautbriefe");
+        assertThat(result.getName()).isEqualTo("Brautbriefe");
+        assertThat(result.getParentId()).isEqualTo(parentId);
+    }
+
+    @Test
+    void upsertBySourceRef_updatesInPlace_whenSourceRefExists() {
+        Tag existing = Tag.builder().id(UUID.randomUUID()).name("Brautbriefe")
+                .sourceRef("Themen/Brautbriefe").build();
+        when(tagRepository.findBySourceRef("Themen/Brautbriefe")).thenReturn(Optional.of(existing));
+        when(tagRepository.save(any())).thenAnswer(inv -> inv.getArgument(0));
+
+        tagService.upsertBySourceRef("Themen/Brautbriefe", "Brautbriefe", null);
+
+        verify(tagRepository).save(argThat(t -> t.getId().equals(existing.getId())));
+        verify(tagRepository, never()).save(argThat(t -> t.getId() == null));
+    }
+
+    @Test
+    void upsertBySourceRef_preservesHumanRenamedTag_onReimport() {
+        Tag humanRenamed = Tag.builder().id(UUID.randomUUID()).name("Verlobungsbriefe")
+                .sourceRef("Themen/Brautbriefe").build();
+        when(tagRepository.findBySourceRef("Themen/Brautbriefe")).thenReturn(Optional.of(humanRenamed));
+        when(tagRepository.save(any())).thenAnswer(inv -> inv.getArgument(0));
+
+        Tag result = tagService.upsertBySourceRef("Themen/Brautbriefe", "Brautbriefe", null);
+
+        assertThat(result.getName()).isEqualTo("Verlobungsbriefe");
+    }
+}
diff --git a/backend/src/test/java/org/raddatz/familienarchiv/user/AdminControllerTest.java b/backend/src/test/java/org/raddatz/familienarchiv/user/AdminControllerTest.java
index b87b928b..8e51fad7 100644
--- a/backend/src/test/java/org/raddatz/familienarchiv/user/AdminControllerTest.java
+++ b/backend/src/test/java/org/raddatz/familienarchiv/user/AdminControllerTest.java
@@ -7,7 +7,8 @@ import org.raddatz.familienarchiv.security.PermissionAspect;
 import org.raddatz.familienarchiv.user.CustomUserDetailsService;
 import org.raddatz.familienarchiv.document.DocumentService;
 import org.raddatz.familienarchiv.document.DocumentVersionService;
-import org.raddatz.familienarchiv.importing.MassImportService;
+import org.raddatz.familienarchiv.importing.CanonicalImportOrchestrator;
+import org.raddatz.familienarchiv.importing.ImportStatus;
 import org.raddatz.familienarchiv.document.ThumbnailBackfillService;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.autoconfigure.aop.AopAutoConfiguration;
@@ -35,7 +36,7 @@ class AdminControllerTest {
 
     @Autowired MockMvc mockMvc;
 
-    @MockitoBean MassImportService massImportService;
+    @MockitoBean CanonicalImportOrchestrator importOrchestrator;
     @MockitoBean DocumentService documentService;
     @MockitoBean DocumentVersionService documentVersionService;
     @MockitoBean ThumbnailBackfillService thumbnailBackfillService;
@@ -46,9 +47,9 @@ class AdminControllerTest {
     @Test
     @WithMockUser(authorities = "ADMIN")
     void importStatus_returns200_withStatusCode_whenAdmin() throws Exception {
-        MassImportService.ImportStatus status = new MassImportService.ImportStatus(
-                MassImportService.State.IDLE, "IMPORT_IDLE", "Kein Import gestartet.", 0, List.of(), null);
-        when(massImportService.getStatus()).thenReturn(status);
+        ImportStatus status = new ImportStatus(
+                ImportStatus.State.IDLE, "IMPORT_IDLE", "Kein Import gestartet.", 0, List.of(), null);
+        when(importOrchestrator.getStatus()).thenReturn(status);
 
         mockMvc.perform(get("/api/admin/import-status"))
                 .andExpect(status().isOk())
@@ -60,9 +61,9 @@ class AdminControllerTest {
     @Test
     @WithMockUser(authorities = "ADMIN")
     void importStatus_messageField_notPresentInApiResponse() throws Exception {
-        MassImportService.ImportStatus status = new MassImportService.ImportStatus(
-                MassImportService.State.IDLE, "IMPORT_IDLE", "Kein Import gestartet.", 0, List.of(), null);
-        when(massImportService.getStatus()).thenReturn(status);
+        ImportStatus status = new ImportStatus(
+                ImportStatus.State.IDLE, "IMPORT_IDLE", "Kein Import gestartet.", 0, List.of(), null);
+        when(importOrchestrator.getStatus()).thenReturn(status);
 
         mockMvc.perform(get("/api/admin/import-status"))
                 .andExpect(status().isOk())
diff --git a/docs/DEPLOYMENT.md b/docs/DEPLOYMENT.md
index c6560a0a..0e1fe07e 100644
--- a/docs/DEPLOYMENT.md
+++ b/docs/DEPLOYMENT.md
@@ -559,20 +559,40 @@ bash scripts/download-kraken-models.sh
 
 > Downloads the Kurrent/Sütterlin HTR models. Run once after a fresh clone or when models are updated.
 
-### Trigger a mass import (Excel/ODS)
+### Trigger a canonical import
 
-**Dev:** drop the ODS spreadsheet + PDFs into `./import/` at the repo root — the dev compose bind-mounts it to `/import` automatically.
+The importer no longer parses the raw spreadsheet. It consumes the **canonical artifacts**
+produced by the normalizer (`tools/import-normalizer/`) — `canonical-tag-tree.xlsx`,
+`canonical-persons.xlsx`, `canonical-persons-tree.json`, `canonical-documents.xlsx` — which
+are committed under `tools/import-normalizer/out/`. The semantic transformation
+(German-date parsing, name classification) lives entirely in the normalizer; the backend
+maps the clean columns by header name. See [ADR-025](adr/025-canonical-import-and-single-migration-schema-foundation.md).
+
+**Prerequisite — regenerate the artifacts when the source data changes:**
+
+```bash
+cd tools/import-normalizer
+python3 -m venv .venv && .venv/bin/pip install -r requirements.txt   # once, on a fresh clone
+.venv/bin/python normalize.py
+# writes the four canonical artifacts into ./out/
+```
+
+**Dev:** place all four canonical artifacts **plus** the referenced PDFs into `./import/`
+at the repo root (the dev compose bind-mounts it to `/import`, which is `app.import.dir`).
+The orchestrator smoke-checks that all four artifacts are present before starting and fails
+closed (`IMPORT_ARTIFACT_INVALID`) if any is missing.
 
 **Staging/production:**
 
-1. Pre-stage the payload on the host. Convention: `/srv/familienarchiv-staging/import/` or `/srv/familienarchiv-production/import/`.
+1. Pre-stage the four canonical artifacts + PDFs on the host. Convention:
+   `/srv/familienarchiv-staging/import/` or `/srv/familienarchiv-production/import/`.
    ```bash
    rsync -avh --progress ./import/ user@host:/srv/familienarchiv-staging/import/
    ```
 2. Make sure `IMPORT_HOST_DIR=<host-path>` is set in `.env.staging` / `.env.production` (the nightly/release workflows already write this — see §3). Compose refuses to start without it.
 3. Redeploy the stack so the bind mount picks up — or, if the mount is already in place, skip to step 4.
 4. Call `POST /api/admin/trigger-import` (requires `ADMIN` permission), or click the "Import starten" button on `/admin/system`.
-5. The import runs asynchronously — poll `GET /api/admin/import-status`, watch `/admin/system`, or tail the backend logs.
+5. The import runs asynchronously — poll `GET /api/admin/import-status`, watch `/admin/system`, or tail the backend logs. Re-running is safe and idempotent (upsert by `source_ref` / document `index`). Person and tag scalar fields you edited in the app are preserved on re-import; a document's sender/receivers/tags are **canonical-authoritative** — a re-import re-applies them to exactly match the export, so a link removed from the export is removed from the document (the raw sender/receiver cell text is always kept).
 
 ---
 
diff --git a/docs/GLOSSARY.md b/docs/GLOSSARY.md
index 1fefb7af..074f2fe1 100644
--- a/docs/GLOSSARY.md
+++ b/docs/GLOSSARY.md
@@ -64,9 +64,13 @@ _See also [Annotation](#annotation-documentannotation)._
 - `REVIEWED`: a reviewer has approved the transcription.
 - `ARCHIVED`: the document is finalized and read-only.
 
-**Mass import** — an asynchronous batch process (`MassImportService`) that reads an Excel or ODS file and creates `Person`s, `Tag`s, and `PLACEHOLDER` `Document`s in one shot. Only one import can run at a time (`IMPORT_ALREADY_RUNNING` error if attempted concurrently).
+**Canonical import** — an asynchronous batch process (`CanonicalImportOrchestrator`) that consumes the normalizer's committed canonical artifacts and creates `Tag`s, `Person`s (register + tree), family relationships, and `Document`s. Four idempotent loaders run in a fixed dependency order — `TagTreeImporter` → `PersonRegisterImporter` → `PersonTreeImporter` → `DocumentImporter` — each calling the owning domain's service. Re-running it never duplicates rows (upsert by `source_ref` / document `index`) and never overwrites a human-edited field. Only one import can run at a time (`IMPORT_ALREADY_RUNNING` error if attempted concurrently); a missing or malformed artifact fails closed (`IMPORT_ARTIFACT_INVALID`). Replaced the legacy raw-spreadsheet `MassImportService` (see ADR-025).
 
-**SkippedFile** (`MassImportService.SkippedFile`) — a file that was presented for import but not processed, recorded with a `filename` and a `reason` code. Possible reasons: `INVALID_PDF_SIGNATURE` (magic-byte validation failed), `S3_UPLOAD_FAILED` (file upload to MinIO/S3 threw an exception), `FILE_READ_ERROR` (the file could not be opened for reading), or `ALREADY_EXISTS` (a document with the same filename already exists in the archive with a status other than `PLACEHOLDER`).
+**canonical artifact** — one of the four files the normalizer (`tools/import-normalizer/`) emits and commits to `tools/import-normalizer/out/`: `canonical-tag-tree.xlsx`, `canonical-persons.xlsx`, `canonical-persons-tree.json`, `canonical-documents.xlsx`. They are the contract the backend importer reads (mapped by header name); the semantic transformation (German-date parsing, name classification) lives only in the normalizer, never in Java.
+
+**CanonicalSheetReader** — the value-level POI helper that opens a canonical `.xlsx`, maps the header row to column indices by name (replacing the brittle positional column config), splits pipe-delimited list columns, and throws `IMPORT_ARTIFACT_INVALID` on a missing required header rather than NPE-ing on a null index.
+
+**SkippedFile** (`ImportStatus.SkippedFile`) — a file that was presented for import but not processed, recorded with a `filename` and a `reason` code. Possible reasons: `INVALID_FILENAME_PATH_TRAVERSAL` (the file-column basename failed the path-traversal guard), `INVALID_PDF_SIGNATURE` (magic-byte validation failed), `S3_UPLOAD_FAILED` (file upload to MinIO/S3 threw an exception), `FILE_READ_ERROR` (the file could not be opened for reading), or `ALREADY_EXISTS` (a document with the same `index` already exists in the archive with a status other than `PLACEHOLDER`).
 
 **skipped count** — the total number of `SkippedFile` entries accumulated during a single import run (`ImportStatus.skipped()`). Shown in the amber warning section of the Import Status Card in the admin UI; a value of zero suppresses the section entirely.
 
diff --git a/docs/adr/025-canonical-import-and-single-migration-schema-foundation.md b/docs/adr/025-canonical-import-and-single-migration-schema-foundation.md
index 0feb670b..3515413b 100644
--- a/docs/adr/025-canonical-import-and-single-migration-schema-foundation.md
+++ b/docs/adr/025-canonical-import-and-single-migration-schema-foundation.md
@@ -2,7 +2,7 @@
 
 **Date:** 2026-05-27
 **Status:** Accepted
-**Issue:** #671
+**Issue:** #671 (schema, decisions 1–2); #669 (importer architecture, decision 3)
 **Milestone:** Handling the Unknowns — honest uncertainty in dates & people
 
 ---
@@ -56,6 +56,59 @@ The importer reads the Python normalizer's canonical output
 output strings are persisted as-is. The same applies to `source_ref`, which carries the
 normalizer's `person_id` / canonical `tag_path` unchanged as the re-import idempotency key.
 
+### 3. The importer is four idempotent loaders over the canonical artifacts; Java no longer parses the raw spreadsheet (Phase 3, #669)
+
+The legacy `MassImportService` read the *raw* original spreadsheet by positional column
+index (`@Value app.import.col.*`) and re-derived everything in Java (ISO-only date parsing,
+name classification via `findOrCreateByAlias`, an ODS/XXE XML path). It is **deleted**.
+
+The rebuild is a `CanonicalImportOrchestrator` driving four single-responsibility loaders in
+an explicit dependency DAG — `TagTreeImporter` → `PersonRegisterImporter` →
+`PersonTreeImporter` → `DocumentImporter` — that **consume the committed canonical artifacts**
+(`tools/import-normalizer/out/`). A shared `CanonicalSheetReader` maps columns **by header
+name** (not by index) and fails closed (`IMPORT_ARTIFACT_INVALID`) on a missing header. Each
+loader calls the **owning domain's service**, never a repository (layering rule); the tree
+loader uses `RelationshipService`, never the relationship repository.
+
+Settled sub-decisions:
+
+- **Idempotency precedence is domain-specific.** Persons/tags upsert by `source_ref`,
+  documents by `index`. Two distinct rules apply:
+  - **Person/Tag scalar fields = preserve human edits.** On re-import a non-blank field a human
+    changed in-app is never overwritten (blank fields are filled from canonical via the single
+    `preferHuman` idiom), and `provisional` is monotonic-downward — once a human confirms a
+    person (`false`) it never reverts to `true`. Because the orchestrator loads the register and
+    tree *before* documents, a person already `false` can never be flipped provisional by a
+    later document row that references the same `source_ref`, regardless of document-row order.
+  - **Document sender/receivers/tags = canonical-authoritative.** A document's sender, receiver
+    set, and tag set are owned by the canonical row, not the archivist. On re-import of a
+    PLACEHOLDER document `DocumentImporter` clears and re-populates `receivers`/`tags` so a row
+    whose set *shrinks* prunes the removed links rather than accumulating stale ones. The
+    "preserve human edits" rule above does **not** extend to these collections. The raw
+    `sender_text`/`receiver_text` cells are always retained verbatim (a separate invariant).
+    Note non-PLACEHOLDER documents are skipped entirely (`ALREADY_EXISTS`), so once a document
+    has a file the importer never touches it again — this bounds the authoritative-overwrite
+    blast radius to placeholder rows.
+  Verified against real Postgres in `CanonicalImportIntegrationTest`
+  (`reimport_preservesHumanEditedPersonField`, `reimport_prunesRemovedReceiverAndTag…`,
+  `import_neverFlipsRegisterPersonToProvisional…`).
+- **Name policy = Option A.** The normalizer resolved attribution upstream: the document sheet
+  carries the resolved slug in `sender_person_id` / `receiver_person_ids` and the raw cell in
+  `sender_name` / `receiver_names`. The importer routes register-first by `source_ref`
+  (provisional `Person` when a slug is unmatched), and **always retains the raw cell** in
+  `sender_text` / `receiver_text` even when a person is linked — the load-bearing invariant
+  behind the merge story. A row with no slug but raw text (prose / `?` / object-noise) links
+  no person and keeps only the raw text.
+- **`provisional` is now populated.** Importer-minted persons are `provisional = true`;
+  register and tree persons stay `false`. This is the Phase-3 contract the schema (decision 1)
+  left at default-`false`.
+- **Security guards are defense-in-depth, not upstream-trust.** The `file` column is treated as
+  hostile (CWE-22 does not care it came from our tool): its basename is validated
+  (`isValidImportFilename` — slash/backslash, three Unicode slash homoglyphs, `..`, null byte,
+  absolute path) and resolved only inside the import dir with canonical-path containment, so a
+  traversal value can never escape. The `%PDF` magic-byte check gates upload. These guards and
+  their tests were ported from `MassImportService` **before** it was deleted.
+
 ---
 
 ## Consequences
@@ -76,6 +129,20 @@ normalizer's `person_id` / canonical `tag_path` unchanged as the re-import idemp
 - **Forward-only.** The migration is immutable once shipped (Flyway checksum model); any fix
   goes in a later version. There is no down-migration — rollback means restoring from the
   nightly `pg_dump`, the standard procedure.
+- **`runImport()` is non-transactional — per-loader transactions only.** The orchestrator
+  does not wrap the four loaders in a single transaction; each loader (or the per-call
+  `upsertBySourceRef` / `DocumentImporter.load`) carries its own `@Transactional` boundary. A
+  partial failure mid-run (e.g. the document loader throws after tags + persons committed)
+  leaves the earlier loaders' data committed and the `ImportStatus` set to `FAILED`. This is
+  acceptable precisely because the import is idempotent: re-running is safe and converges to
+  the same state, so the operational recovery for a partial failure is simply to fix the
+  offending artifact and re-trigger the import — no manual cleanup of half-written data is
+  required. A future maintainer must not assume all-or-nothing semantics.
+- **Path-escape aborts the whole import (fail-closed), by design.** A path-traversal or
+  symlink-escape in a row's file path is treated as an attack signal: the import aborts rather
+  than recording the row as a `SkippedFile` and continuing. This is a deliberate owner decision
+  (2026-05-27) over a per-file skip — a malicious path must surface loudly, not be silently
+  tolerated.
 - **`PersonSummaryDTO` coupling.** `provisional` was added to the `PersonSummaryDTO` native
   interface projection; because the projection is backed by native SQL, the column had to be
   added to all three native `SELECT`s (`findAllWithDocumentCount`, `searchWithDocumentCount`,
diff --git a/docs/architecture/c4/l3-backend-3b-document-management.puml b/docs/architecture/c4/l3-backend-3b-document-management.puml
index a15eb00b..89d4a68b 100644
--- a/docs/architecture/c4/l3-backend-3b-document-management.puml
+++ b/docs/architecture/c4/l3-backend-3b-document-management.puml
@@ -1,7 +1,7 @@
 @startuml
 !include <C4/C4_Component>
 
-title Component Diagram: API Backend — Document Management & Import
+title Component Diagram: API Backend — Document Management & Canonical Import
 
 Container(frontend, "Web Frontend", "SvelteKit")
 ContainerDb(db, "PostgreSQL", "PostgreSQL 16")
@@ -9,30 +9,48 @@ ContainerDb(minio, "Object Storage", "MinIO (S3-compatible)")
 
 System_Boundary(backend, "API Backend (Spring Boot)") {
     Component(docCtrl, "DocumentController", "Spring MVC — /api/documents", "CRUD for documents: search, get by ID, update metadata, upload/download file, conversation thread, batch metadata updates, and per-month density aggregation for the timeline filter widget.")
-    Component(adminCtrl, "AdminController", "Spring MVC — /api/admin", "Triggers asynchronous Excel/ODS mass import (requires ADMIN permission). Reports import state (IDLE/RUNNING/DONE/FAILED).")
+    Component(adminCtrl, "AdminController", "Spring MVC — /api/admin", "Triggers the asynchronous canonical import (requires ADMIN permission). Reports import state (IDLE/RUNNING/DONE/FAILED).")
     Component(docSvc, "DocumentService", "Spring Service", "Core document business logic: store, update, search. Resolves persons and tags, delegates file I/O to FileService, builds dynamic JPA Specifications, and integrates with audit logging.")
     Component(fileSvc, "FileService", "Spring Service", "Wraps AWS SDK v2 S3Client. Uploads files with UUID-keyed paths, computes SHA-256 hash, downloads with content-type detection, and generates presigned URLs for OCR access.")
-    Component(massImport, "MassImportService", "Spring Service — @Async", "Reads Excel/ODS files from /import mount. Tracks import state (IDLE/RUNNING/DONE/FAILED) and delegates to ExcelService. Returns immediately; processing runs asynchronously.")
-    Component(excelSvc, "ExcelService", "Spring Service", "Parses Excel/ODS workbooks (Apache POI). Column indices configurable via application.properties. Creates/updates document records per row.")
+    Component(importOrch, "CanonicalImportOrchestrator", "Spring Service — @Async", "Runs the four canonical loaders in an explicit dependency DAG (TagTree → PersonRegister → PersonTree → Document). Smoke-checks all four artifacts before starting, owns the IDLE/RUNNING/DONE/FAILED state machine, fails closed on a malformed artifact.")
+    Component(tagTreeLoader, "TagTreeImporter", "Spring Component", "Upserts the tag hierarchy from canonical-tag-tree.xlsx via TagService (by canonical tag_path).")
+    Component(personRegLoader, "PersonRegisterImporter", "Spring Component", "Upserts register persons from canonical-persons.xlsx via PersonService (by normalizer person_id).")
+    Component(personTreeLoader, "PersonTreeImporter", "Spring Component", "Upserts tree persons + relationships from canonical-persons-tree.json via PersonService and RelationshipService.")
+    Component(docLoader, "DocumentImporter", "Spring Component", "Loads canonical-documents.xlsx: routes attribution register-first (raw cell always retained in sender_text/receiver_text), parses clean dates, keeps the S3 upload + thumbnail plumbing, and ports the path-traversal / homoglyph / absolute-path / %PDF magic-byte security guards.")
+    Component(sheetReader, "CanonicalSheetReader", "POI helper", "Maps a canonical .xlsx by header name (no positional indices), splits pipe-delimited list columns, fails closed (IMPORT_ARTIFACT_INVALID) on a missing required header.")
     Component(minioConf, "MinioConfig", "Spring @Configuration", "Creates the S3Client and S3Presigner beans with path-style access for MinIO. Validates MinIO connectivity on startup.")
     Component(docRepo, "DocumentRepository", "Spring Data JPA", "Queries documents with Specification-based dynamic search, bidirectional conversation thread queries, full-text search with ranking and match highlighting, and transcription pipeline queue projections.")
     Component(docSpec, "DocumentSpecifications", "JPA Criteria API", "Factory for composable predicates: hasText (full-text), hasSender, hasReceiver, isBetween (date range), hasTags (subquery AND/OR logic).")
 }
 
-Component(personSvc, "PersonService", "Spring Service", "See diagram 3e. Called by DocumentService to resolve sender / receiver persons by ID.")
-Component(tagSvc, "TagService", "Spring Service", "See diagram 3d. Called by DocumentService to find or create tags by name.")
+Component(personSvc, "PersonService", "Spring Service", "See diagram 3e. Resolves sender / receiver persons by ID; upserts persons by source_ref for the importer.")
+Component(tagSvc, "TagService", "Spring Service", "See diagram 3d. Finds or creates tags by name; upserts tags by source_ref for the importer.")
+Component(relSvc, "RelationshipService", "Spring Service", "See diagram 3e. Creates family relationships from the person tree during import.")
 
 Rel(frontend, docCtrl, "Document requests", "HTTP / JSON")
 Rel(frontend, adminCtrl, "Trigger import", "HTTP / JSON")
 Rel(docCtrl, docSvc, "Delegates to")
-Rel(adminCtrl, massImport, "Triggers")
+Rel(adminCtrl, importOrch, "Triggers")
 Rel(docSvc, fileSvc, "Upload / download files")
 Rel(docSvc, docRepo, "Reads / writes documents")
 Rel(docSvc, docSpec, "Builds search predicates")
 Rel(docSvc, personSvc, "Resolves sender / receivers")
 Rel(docSvc, tagSvc, "Finds or creates tags")
-Rel(massImport, excelSvc, "Parses Excel/ODS file")
-Rel(excelSvc, docSvc, "Creates / updates documents")
+Rel(importOrch, tagTreeLoader, "1. Loads tags")
+Rel(importOrch, personRegLoader, "2. Loads register persons")
+Rel(importOrch, personTreeLoader, "3. Loads tree persons + relationships")
+Rel(importOrch, docLoader, "4. Loads documents")
+Rel(tagTreeLoader, sheetReader, "Reads canonical .xlsx")
+Rel(personRegLoader, sheetReader, "Reads canonical .xlsx")
+Rel(docLoader, sheetReader, "Reads canonical .xlsx")
+Rel(tagTreeLoader, tagSvc, "Upserts tags by source_ref")
+Rel(personRegLoader, personSvc, "Upserts persons by source_ref")
+Rel(personTreeLoader, personSvc, "Upserts persons by source_ref")
+Rel(personTreeLoader, relSvc, "Creates relationships")
+Rel(docLoader, docSvc, "Upserts documents by index")
+Rel(docLoader, personSvc, "Register-first match / provisional person")
+Rel(docLoader, tagSvc, "Attaches tag by source_ref")
+Rel(docLoader, fileSvc, "Uploads resolved file")
 Rel(minioConf, fileSvc, "Provides S3Client and S3Presigner beans")
 Rel(fileSvc, minio, "PUT / GET / presigned URL objects", "S3 API / HTTP")
 Rel(docRepo, db, "SQL queries", "JDBC")
diff --git a/frontend/messages/de.json b/frontend/messages/de.json
index 52087452..a54ab59e 100644
--- a/frontend/messages/de.json
+++ b/frontend/messages/de.json
@@ -14,6 +14,7 @@
 	"error_file_too_large": "Die Datei ist zu groß (max. 50 MB).",
 	"error_user_not_found": "Der Benutzer wurde nicht gefunden.",
 	"error_import_already_running": "Ein Import läuft bereits. Bitte warten Sie, bis dieser abgeschlossen ist.",
+	"error_import_artifact_invalid": "Eine Importdatei fehlt oder ist ungültig. Bitte führen Sie den Normalizer erneut aus.",
 	"error_invalid_credentials": "E-Mail-Adresse oder Passwort ist falsch.",
 	"error_session_expired": "Ihre Sitzung ist abgelaufen. Bitte melden Sie sich erneut an.",
 	"error_session_expired_explainer": "Aus Sicherheitsgründen werden Sitzungen nach 8 Stunden Inaktivität automatisch beendet.",
@@ -356,11 +357,13 @@
 	"admin_system_import_status_done_label": "Dokumente verarbeitet",
 	"admin_system_import_skipped_label": "übersprungen",
 	"import_reason_invalid_pdf_signature": "Keine gültige PDF-Signatur",
+	"import_reason_path_traversal": "Ungültiger Dateiname (Pfad)",
 	"import_reason_file_read_error": "Fehler beim Lesen der Datei",
 	"import_reason_s3_upload_failed": "Upload-Fehler (S3)",
 	"import_reason_already_exists": "Bereits importiert",
 	"admin_system_import_status_failed": "Import fehlgeschlagen",
 	"admin_system_import_failed_no_spreadsheet": "Keine Tabellendatei gefunden.",
+	"admin_system_import_failed_artifact": "Eine Importdatei fehlt oder ist ungültig.",
 	"admin_system_import_failed_internal": "Interner Fehler beim Import.",
 	"admin_system_thumbnails_heading": "Thumbnails erzeugen",
 	"admin_system_thumbnails_description": "Erzeugt Vorschaubilder für Dokumente ohne Thumbnail (z. B. nach dem Massenimport).",
diff --git a/frontend/messages/en.json b/frontend/messages/en.json
index 3e2c3ff8..5c6ca80a 100644
--- a/frontend/messages/en.json
+++ b/frontend/messages/en.json
@@ -14,6 +14,7 @@
 	"error_file_too_large": "The file is too large (max. 50 MB).",
 	"error_user_not_found": "User not found.",
 	"error_import_already_running": "An import is already running. Please wait for it to finish.",
+	"error_import_artifact_invalid": "A canonical import file is missing or invalid. Please re-run the normalizer.",
 	"error_invalid_credentials": "Email address or password is incorrect.",
 	"error_session_expired": "Your session has expired. Please sign in again.",
 	"error_session_expired_explainer": "For security reasons, sessions are automatically ended after 8 hours of inactivity.",
@@ -356,11 +357,13 @@
 	"admin_system_import_status_done_label": "Documents processed",
 	"admin_system_import_skipped_label": "skipped",
 	"import_reason_invalid_pdf_signature": "Invalid PDF signature",
+	"import_reason_path_traversal": "Invalid filename (path)",
 	"import_reason_file_read_error": "File read error",
 	"import_reason_s3_upload_failed": "Upload error (S3)",
 	"import_reason_already_exists": "Already imported",
 	"admin_system_import_status_failed": "Import failed",
 	"admin_system_import_failed_no_spreadsheet": "No spreadsheet file found.",
+	"admin_system_import_failed_artifact": "A canonical import file is missing or invalid.",
 	"admin_system_import_failed_internal": "Import failed due to an internal error.",
 	"admin_system_thumbnails_heading": "Generate thumbnails",
 	"admin_system_thumbnails_description": "Generates preview images for documents without a thumbnail (e.g. after the mass import).",
diff --git a/frontend/messages/es.json b/frontend/messages/es.json
index 972eecb8..cbda7fab 100644
--- a/frontend/messages/es.json
+++ b/frontend/messages/es.json
@@ -14,6 +14,7 @@
 	"error_file_too_large": "El archivo es demasiado grande (máx. 50 MB).",
 	"error_user_not_found": "Usuario no encontrado.",
 	"error_import_already_running": "Ya hay una importación en curso. Por favor, espere a que finalice.",
+	"error_import_artifact_invalid": "Falta un archivo de importación canónico o no es válido. Vuelva a ejecutar el normalizador.",
 	"error_invalid_credentials": "El correo electrónico o la contraseña son incorrectos.",
 	"error_session_expired": "Su sesión ha expirado. Por favor, inicie sesión de nuevo.",
 	"error_session_expired_explainer": "Por razones de seguridad, las sesiones se terminan automáticamente tras 8 horas de inactividad.",
@@ -356,11 +357,13 @@
 	"admin_system_import_status_done_label": "Documentos procesados",
 	"admin_system_import_skipped_label": "omitidos",
 	"import_reason_invalid_pdf_signature": "Firma PDF no válida",
+	"import_reason_path_traversal": "Nombre de archivo no válido (ruta)",
 	"import_reason_file_read_error": "Error al leer el archivo",
 	"import_reason_s3_upload_failed": "Error de carga (S3)",
 	"import_reason_already_exists": "Ya importado",
 	"admin_system_import_status_failed": "Importación fallida",
 	"admin_system_import_failed_no_spreadsheet": "No se encontró ninguna hoja de cálculo.",
+	"admin_system_import_failed_artifact": "Falta un archivo de importación canónico o no es válido.",
 	"admin_system_import_failed_internal": "Error interno durante la importación.",
 	"admin_system_thumbnails_heading": "Generar miniaturas",
 	"admin_system_thumbnails_description": "Genera imágenes de vista previa para documentos sin miniatura (p. ej. tras la importación masiva).",
diff --git a/frontend/src/lib/shared/errors.ts b/frontend/src/lib/shared/errors.ts
index 96700120..dcdb9f25 100644
--- a/frontend/src/lib/shared/errors.ts
+++ b/frontend/src/lib/shared/errors.ts
@@ -17,6 +17,7 @@ export type ErrorCode =
 	| 'EMAIL_ALREADY_IN_USE'
 	| 'WRONG_CURRENT_PASSWORD'
 	| 'IMPORT_ALREADY_RUNNING'
+	| 'IMPORT_ARTIFACT_INVALID'
 	| 'INVALID_RESET_TOKEN'
 	| 'INVITE_NOT_FOUND'
 	| 'INVITE_EXHAUSTED'
@@ -104,6 +105,8 @@ export function getErrorMessage(code: ErrorCode | string | undefined): string {
 			return m.error_wrong_current_password();
 		case 'IMPORT_ALREADY_RUNNING':
 			return m.error_import_already_running();
+		case 'IMPORT_ARTIFACT_INVALID':
+			return m.error_import_artifact_invalid();
 		case 'INVALID_RESET_TOKEN':
 			return m.error_invalid_reset_token();
 		case 'INVITE_NOT_FOUND':
diff --git a/frontend/src/routes/admin/system/ImportStatusCard.svelte b/frontend/src/routes/admin/system/ImportStatusCard.svelte
index bb9bce72..e6556857 100644
--- a/frontend/src/routes/admin/system/ImportStatusCard.svelte
+++ b/frontend/src/routes/admin/system/ImportStatusCard.svelte
@@ -13,10 +13,13 @@ let {
 const failureMessage = $derived(
 	importStatus?.statusCode === 'IMPORT_FAILED_NO_SPREADSHEET'
 		? m.admin_system_import_failed_no_spreadsheet()
-		: m.admin_system_import_failed_internal()
+		: importStatus?.statusCode === 'IMPORT_FAILED_ARTIFACT'
+			? m.admin_system_import_failed_artifact()
+			: m.admin_system_import_failed_internal()
 );
 
 function reasonLabel(code: string): string {
+	if (code === 'INVALID_FILENAME_PATH_TRAVERSAL') return m.import_reason_path_traversal();
 	if (code === 'INVALID_PDF_SIGNATURE') return m.import_reason_invalid_pdf_signature();
 	if (code === 'FILE_READ_ERROR') return m.import_reason_file_read_error();
 	if (code === 'S3_UPLOAD_FAILED') return m.import_reason_s3_upload_failed();