diff --git a/tools/import-normalizer/persons.py b/tools/import-normalizer/persons.py
index 968cd7bb..b92823a8 100644
--- a/tools/import-normalizer/persons.py
+++ b/tools/import-normalizer/persons.py
@@ -1,4 +1,5 @@
 """Person register parsing, name splitting, alias resolution."""
+import difflib
 import re
 import unicodedata
 from collections import Counter
@@ -141,3 +142,56 @@ def split_receivers(raw: str) -> list[str]:
         result.append(last_seg)
         return result
     return parts
+
+
+def _norm(name: str) -> str:
+    return re.sub(r"\s+", " ", _strip_accents(name).lower().replace(".", " ")).strip()
+
+
+class AliasIndex:
+    def __init__(self, people: list[Person]):
+        self._by_alias: dict[str, str] = {}
+        self._display: dict[str, str] = {}
+        self.known_ids: set[str] = {p.person_id for p in people}
+        first_name_ids: dict[str, list] = {}
+        for p in people:
+            self._display[p.person_id] = f"{p.first_name} {p.last_name}".strip()
+            # Ordered, de-duplicated forms (NOT a set) so alias order is deterministic — NFR-IDEM-01.
+            forms = [f"{p.first_name} {p.last_name}".strip()]
+            if p.maiden_name:
+                forms.append(f"{p.first_name} {p.maiden_name}".strip())
+            for extra in p.extra_given_names:
+                forms.append(f"{extra} {p.last_name}".strip())
+            if p.nickname:
+                forms.append(p.nickname)
+            seen = set()
+            for form in forms:
+                if form in seen:
+                    continue
+                seen.add(form)
+                key = _norm(form)
+                if key and key not in self._by_alias:
+                    self._by_alias[key] = p.person_id
+                    p.aliases.append(form)
+            if p.first_name:
+                ids = first_name_ids.setdefault(_norm(p.first_name), [])
+                if p.person_id not in ids:
+                    ids.append(p.person_id)
+        # first-name-only alias, only when unambiguous
+        for fname, ids in first_name_ids.items():
+            if len(ids) == 1 and fname not in self._by_alias:
+                self._by_alias[fname] = ids[0]
+
+    def resolve(self, name: str):
+        return self._by_alias.get(_norm(name))
+
+    def display(self, person_id: str) -> str:
+        return self._display.get(person_id, "")
+
+    def suggest(self, name: str):
+        keys = list(self._by_alias.keys())
+        match = difflib.get_close_matches(_norm(name), keys, n=1, cutoff=config.FUZZY_SUGGEST_THRESHOLD)
+        if not match:
+            return None, 0.0
+        score = difflib.SequenceMatcher(None, _norm(name), match[0]).ratio()
+        return self._by_alias[match[0]], score
diff --git a/tools/import-normalizer/tests/test_persons.py b/tools/import-normalizer/tests/test_persons.py
index 2137509f..a5c9b0cf 100644
--- a/tools/import-normalizer/tests/test_persons.py
+++ b/tools/import-normalizer/tests/test_persons.py
@@ -1,3 +1,4 @@
+import config
 import persons
 
 def test_slugify():
@@ -52,3 +53,21 @@ def test_split_receivers():
 def test_find_known_last_name():
     assert persons.find_known_last_name("Eugenie de Gruyter") == "de Gruyter"
     assert persons.find_known_last_name("Clara") is None
+
+def test_alias_index_resolves_maiden_and_married():
+    people = persons.parse_register([
+        {"last_name": "de Gruyter", "first_name": "Eugenie", "maiden_name": "Müller"},
+        {"last_name": "Cram", "first_name": "Clara"},
+    ])
+    idx = persons.AliasIndex(people)
+    eugenie = people[0].person_id
+    assert idx.resolve("Eugenie de Gruyter") == eugenie   # canonical
+    assert idx.resolve("Eugenie Müller") == eugenie        # maiden alias
+    assert idx.resolve("eugenie  müller") == eugenie        # normalized
+    assert idx.resolve("Nobody Unknown") is None
+
+def test_alias_index_suggestion():
+    people = persons.parse_register([{"last_name": "Wittkopf", "first_name": "Hans"}])
+    idx = persons.AliasIndex(people)
+    sid, score = idx.suggest("Hans Wittkop")  # typo
+    assert sid == people[0].person_id and score >= config.FUZZY_SUGGEST_THRESHOLD