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 5a0cbd73..e40b122c 100644
--- a/backend/src/main/java/org/raddatz/familienarchiv/exception/ErrorCode.java
+++ b/backend/src/main/java/org/raddatz/familienarchiv/exception/ErrorCode.java
@@ -8,6 +8,10 @@ package org.raddatz.familienarchiv.exception;
  */
 public enum ErrorCode {
 
+    // --- Persons ---
+    /** A person with the given ID does not exist. 404 */
+    PERSON_NOT_FOUND,
+
     // --- Documents ---
     /** A document with the given ID does not exist. 404 */
     DOCUMENT_NOT_FOUND,
diff --git a/backend/src/main/java/org/raddatz/familienarchiv/service/PersonService.java b/backend/src/main/java/org/raddatz/familienarchiv/service/PersonService.java
index 52f6231c..9926ea1d 100644
--- a/backend/src/main/java/org/raddatz/familienarchiv/service/PersonService.java
+++ b/backend/src/main/java/org/raddatz/familienarchiv/service/PersonService.java
@@ -5,6 +5,8 @@ import java.util.Optional;
 import java.util.UUID;
 
 import org.raddatz.familienarchiv.dto.PersonUpdateDTO;
+import org.raddatz.familienarchiv.exception.DomainException;
+import org.raddatz.familienarchiv.exception.ErrorCode;
 import org.raddatz.familienarchiv.model.Person;
 import org.raddatz.familienarchiv.repository.PersonRepository;
 import org.springframework.http.HttpStatus;
@@ -29,7 +31,7 @@ public class PersonService {
 
     public Person getById(UUID id) {
         return personRepository.findById(id)
-                .orElseThrow(() -> new ResponseStatusException(HttpStatus.NOT_FOUND, "Person nicht gefunden"));
+                .orElseThrow(() -> DomainException.notFound(ErrorCode.PERSON_NOT_FOUND, "Person not found: " + id));
     }
 
     public List<Person> findCorrespondents(UUID personId, String q) {
@@ -86,7 +88,7 @@ public class PersonService {
     public Person updatePerson(UUID id, PersonUpdateDTO dto) {
         validateYears(dto.getBirthYear(), dto.getDeathYear());
         Person person = personRepository.findById(id)
-                .orElseThrow(() -> new ResponseStatusException(HttpStatus.NOT_FOUND, "Person nicht gefunden"));
+                .orElseThrow(() -> DomainException.notFound(ErrorCode.PERSON_NOT_FOUND, "Person not found: " + id));
         person.setFirstName(dto.getFirstName());
         person.setLastName(dto.getLastName());
         person.setAlias(dto.getAlias() == null || dto.getAlias().isBlank() ? null : dto.getAlias().trim());
@@ -102,9 +104,9 @@ public class PersonService {
             throw new ResponseStatusException(HttpStatus.BAD_REQUEST, "Quelle und Ziel dürfen nicht identisch sein");
         }
         personRepository.findById(sourceId)
-                .orElseThrow(() -> new ResponseStatusException(HttpStatus.NOT_FOUND, "Quell-Person nicht gefunden"));
+                .orElseThrow(() -> DomainException.notFound(ErrorCode.PERSON_NOT_FOUND, "Source person not found: " + sourceId));
         personRepository.findById(targetId)
-                .orElseThrow(() -> new ResponseStatusException(HttpStatus.NOT_FOUND, "Ziel-Person nicht gefunden"));
+                .orElseThrow(() -> DomainException.notFound(ErrorCode.PERSON_NOT_FOUND, "Target person not found: " + targetId));
 
         // Reassign sender references
         personRepository.reassignSender(sourceId, targetId);
diff --git a/backend/src/test/java/org/raddatz/familienarchiv/service/PersonServiceTest.java b/backend/src/test/java/org/raddatz/familienarchiv/service/PersonServiceTest.java
index fb0023fe..c8cc2624 100644
--- a/backend/src/test/java/org/raddatz/familienarchiv/service/PersonServiceTest.java
+++ b/backend/src/test/java/org/raddatz/familienarchiv/service/PersonServiceTest.java
@@ -6,6 +6,7 @@ import org.mockito.InjectMocks;
 import org.mockito.Mock;
 import org.mockito.junit.jupiter.MockitoExtension;
 import org.raddatz.familienarchiv.dto.PersonUpdateDTO;
+import org.raddatz.familienarchiv.exception.DomainException;
 import org.raddatz.familienarchiv.model.Person;
 import org.raddatz.familienarchiv.repository.PersonRepository;
 import org.springframework.web.server.ResponseStatusException;
@@ -33,8 +34,8 @@ class PersonServiceTest {
         when(personRepository.findById(id)).thenReturn(Optional.empty());
 
         assertThatThrownBy(() -> personService.getById(id))
-                .isInstanceOf(ResponseStatusException.class)
-                .extracting(e -> ((ResponseStatusException) e).getStatusCode().value())
+                .isInstanceOf(DomainException.class)
+                .extracting(e -> ((DomainException) e).getStatus().value())
                 .isEqualTo(404);
     }
 
@@ -371,8 +372,8 @@ class PersonServiceTest {
         when(personRepository.findById(sourceId)).thenReturn(Optional.empty());
 
         assertThatThrownBy(() -> personService.mergePersons(sourceId, targetId))
-                .isInstanceOf(ResponseStatusException.class)
-                .extracting(e -> ((ResponseStatusException) e).getStatusCode().value())
+                .isInstanceOf(DomainException.class)
+                .extracting(e -> ((DomainException) e).getStatus().value())
                 .isEqualTo(404);
     }
 
@@ -385,8 +386,8 @@ class PersonServiceTest {
         when(personRepository.findById(targetId)).thenReturn(Optional.empty());
 
         assertThatThrownBy(() -> personService.mergePersons(sourceId, targetId))
-                .isInstanceOf(ResponseStatusException.class)
-                .extracting(e -> ((ResponseStatusException) e).getStatusCode().value())
+                .isInstanceOf(DomainException.class)
+                .extracting(e -> ((DomainException) e).getStatus().value())
                 .isEqualTo(404);
     }