diff --git a/doc/adr/2025-02-27-exchanging-the-partner-person.de.md b/doc/adr/2025-02-27-exchanging-the-partner-person.de.md
new file mode 100644
index 00000000..3367cbf2
--- /dev/null
+++ b/doc/adr/2025-02-27-exchanging-the-partner-person.de.md
@@ -0,0 +1,124 @@
+# Änderung eines Geschäftspartners oder Rechnungsempfängers (Debitor)
+
+**Status:**
+- [x] vorgeschlagen von (Michael Hönnig)
+- [ ] akzeptiert von (...)
+- [ ] abgelehnt von (...)
+- [ ] ersetzt durch (ersetzende ADR)
+
+## Kontext und Problemstellung
+
+Im vorgegebenen Datenmodell von Geschäftspartnern und Rechnungsempfängern (Debitoren), das auch fachliche Rollen wie Repräsentant, technische Ansprechpartner oder Mailinglisten-Subscriptions umfasst, stellt sich die Frage, wie eine Änderung der Geschäftspartner-Person effizient und konsistent umgesetzt werden kann.
+Diese fachlichen Rollen hängen jeweils an der Partner-Person.
+
+Ein konkretes Beispiel hierfür ist die Änderung von einer natürlichen Person, die verstorben ist, zu deren Erbengemeinschaft.
+**Hierbei zeigte sich, dass die API-Bedienung durch die Vielzahl neu zu erstellender Objekte und deren Verknüpfungen komplex und fehleranfällig ist. Zudem lassen sich nicht alle Änderung in einer einzigen Transaktion durchführen, was zu Inkonsistenzen führen kann.“** 
+
+Angepasst werden müssen:
+
+1. alle Relations mit der alten Partner-Person:
+- die PARTNER-Relation
+- die DEBITOR-Relations (ggf. mehrere)
+- die OPERATIONS-Relations (ggf. mehrere)
+- die SUBSCRIBER-Relations (ggf. mehrere)
+- die REPRESENTATIVE-Relations (ggf. mehrere)
+- etc.
+2. Die PARTNER-Relation hat die Besonderheit, dass sie vom Partner referenziert wird und daher auch dort ausgetauscht werden muss.
+3. Die DEBITOR-Relation hat die Besonderheit, dass sie vom Debitor referenziert wird und daher auch dort ausgetauscht werden muss.
+
+Daher sollen möglichst viele dieser *Neuverdrahtungen* im Backend gemacht werden.
+Und dafür braucht es dann eine zentrale Stelle, an der die Kaskade ausgelöst wird. 
+
+Derzeit gibt es drei mögliche Varianten, diese Änderung dynamisch umzusetzen, die jeweils unterschiedliche Auswirkungen auf Aufwände, API und Zugriffsrechte haben.
+
+### Technischer Hintergrund
+
+Zum Zeitpunkt der Erstellung dieses ADR existieren folgende relevante Entitäten:
+- **Person**: Natürliche oder juristische Person (Name, Firma, Anrede etc.)
+- **Contact**: Kontaktdaten einer fachlichen Rolle
+- **Relation**: Mit einem Typ (z.B. PARTNER, DEBITOR, REPRESENTATIVE) und Kontaktdaten versehene Beziehung von einer Person (Holder) zu einer anderen (Anchor)
+- **Partner**: Sind quasi Zusatzdaten einer PARTNER-Relation (derzeit nur die Partnernummer), welche eine Partner-Person mit der Hostsharing-Person verknüpft
+- **Debitor**: Sind quasi Zusatzdaten einer DEBITOR-Relation, welche eine Debitor-Person mit einer Partner-Person verknüpft
+
+Zugriffsrechte werden über ein hierarchisches, dynamisches RBAC-System gesteuert, bei dem der **OWNER** einer Entitäten-Instanz alle Rechte hat, **ADMIN** definierte Spalten aktualisieren darf, **AGENT** Verknüpfungen anlegen kann, und **TENANT**, **GUEST** sowie **REFERRER** nur Lesezugriff haben.
+Partner und Debitor nutzen dabei die RBAC-Rollen der zugehörigen Relations.
+
+## In Betracht gezogene Varianten
+
+* **1. Relations ersetzen:** Austausch der PARTNER-/DEBITOR-/OPERATIONS-/...-Relations gegen eine neue Relation für die neue Partner-Person (z.B. Erbengemeinschaft) als neuen Holder als PATCH auf /api/hs/office/partners/UUID
+* **2. Relations direkt aktualisieren:** Änderung der Holder-Referenz in der bestehenden PARTNER-Relation auf die neue Partner-Person (z.B. Erbengemeinschaft) als PATCH auf /api/hs/office/relations/UUID
+* **3. Relations via Partner aktualisieren:** Änderung der Partner-Person in die PARTNER-Relation als PATCH auf /api/hs/office/partners/UUID
+
+### Variante 1: Relations ersetzen
+
+Der Austausch der Partner- (und Debitor-) Person erfolgt über das Erstellen einer neuen PARTNER- bzw. DEBITOR-Relation, im Partner bzw. Debitor wird dann die Referenz auf die alte PARTNER- bzw. DEBITOR-Relation gegen die neue ausgetauscht.
+
+#### Vorteile
+
+- **Beibehaltung der API:** Dieses Verhalten ist bereits implementiert und benötigt keinen großen Umbau an der API, sondern nur eine Erweiterung um das Austauschen weiterer Relations.
+- **UPDATE-Permission für AGENT:** Es wäre möglich, der AGENT-Rolle einer Relation UPDATE-Rechte an der Relation zu geben, weil nur die unkritische Contact-Referenz änderbar wäre.
+- **Kongruenz von Fachlichkeit+API**: Fachlich handelt es sich um den Austausch der Partner-Person, dazu passend wäre der Endpunkt, allerdings wird in dieser Variante nicht direkt die Partner-Person ausgetauscht, sondern eine neue PARTNER-Relation mit der neuen Partner-Person eingesetzt.
+
+#### Nachteile
+
+- **Verlust expliziter GRANTs:** Gibt es explizite GRANTs an der PARTNER-Relation, gehen diese verloren, da die Relation ausgetauscht wird. Die Übernahme dieser expliziten Grants erfordert also einen zusätzlichen Implementationsaufwand.
+- **Divergenz zwischen Fachlichkeit und API:** Fachlich handelt es sich um den Austausch der Partner-Person, würde aber eine neue PARTNER-Relation dieser Person in den Partner eingesetzt werden. Das erfordert ein höheres Verständnis des Datenmodells.
+- **Keine Anwendbarkeit auf abhängige Relations:** Beim Aktualisieren der abhängigen Relations (z.B. Representative, Operational- und Billing-Kontakt sowie der Mailinglisten-Subscriptions) stehen wir wieder vor dem Ausgangsproblem und müssten jeweils neue Relations erzeugen und die alten Relations löschen, was dann wieder zum Verlust expliziter GRANTs führt.
+- **Performance bei vielen abhängigen Relations:** die abhängigen Relations können nur über Loops, nicht aber durch direkt SQL UPDATEs ausgetauscht werden, was zu einer schlechteren Performance führt
+
+### Variante 2: Relations direkt aktualisieren
+
+Die bestehende PARTNER-Relation bliebe erhalten, und der Holder wird von der verstorbenen Person auf die Erbengemeinschaft geändert.
+
+#### Vorteile
+
+- **Anwendbarkeit auf Partner- und Debitor-Person:** Der Code wäre an einer generischen Stelle, welche dann Partner- und Debitor-Person austauschbar machen würde
+- **Einheitlichkeit/Generizität der API:** Die REST-API für Änderungen gehört dann einheitlich zum Relation-Endpunkt, was der bestehenden Handhabung von Contact-Änderungen entspricht.
+
+#### Nachteile
+
+- **UPDATE Permission für Relation-AGENT wäre kritisch:** Der Relation-AGENT darf nicht das Recht bekommen, den Holder auszutauschen. Da es keine Spalten-spezifischen Update-Rechte gibt, könnte dieser auch den Contact nicht mehr austauschen. Derzeit ist das allerdings auch noch nicht so implementiert.
+- **Umbau der API:** Der Austausch einer Partner-Person würde vom Partner-Endpunkt (/api/hs/office/partner) zur Relation (/api/hs/office/partner) wandern, was ein größerer Umbau, auch bei den Tests wäre.
+- **Divergenz von Fachlichkeit und API**: Fachlich handelt es sich um den Austausch der Partner-Person, aber man würde die Person nicht am Partner selbst austauschen, sondern an der PARTNER-Relation.
+
+### Variante 3: Relations via Partner aktualisieren
+
+Der Austausch der Partner- (bzw. Debitor-) Person würde weiterhin beim Partner bzw. Debitor erfolgen, jedoch würde die Personen-Referenz direkt in der bestehenden Partner- (bzw. Debitor-) Relation umgesetzt werden, statt eine neue Relation mit der neuen Partner- (bzw. Debitor) Person einzusetzen. Die direkt wie auch abhängige Relations könnten also einfach per SQL UPDATE aktualisiert werden.
+
+#### Vorteile
+
+- **Beibehaltung der API:** Der Endpunkt /api/hs/office/partners/UUID bliebe erhalten, wenn auch lokal ein Umbau auf Person-Update statt Relation-Update erfolgen müsste, Anpassungen in Verwendungen dieser API, z.B. in Tests, wären allerdings wenig aufwändig und das Risiko für weitere Aufwände recht gering.
+- **UPDATE-Permission für AGENT:** Es wäre möglich, der AGENT-Rolle einer Relation UPDATE-Rechte an der Relation zu geben, aber eine Aktualisierung über die REST-Controller nur an kontrollierten Stellen zuzulassen.
+- **Kongruenz von Fachlichkeit+API**: Fachlich handelt es sich um den Austausch der Partner-Person, was auch in dieser Variante technisch abgebildet würde, wenn auch eine Ebene tiefer im JSON, nämlich in der Partner-Relation.
+
+#### Nachteile
+
+Nennenswerte Nachteile wurden nicht identifiziert, allenfalls ist es etwas schräge, dass die RBAC-Rechte an den Relations ein UPDATE zulassen, was aber an der API nur für bestimmte Relations (ggf. kontrolliert) erreichbar wäre.
+
+
+## Entscheidung und Ergebnis
+
+**Entscheidung:** 3. Relations via Partner aktualisieren 
+
+**Begründung:**
+- die Fachlichkeit wird an der API gut abgebildet (PATCH der Partner-Person auf /api/hs/office/partners/UUID)
+- der Aufwand ist relativ gering (vieles ist mit SQL UPDATEs machbar)
+- die UPDATE Permission dürfte an Relation-AGENT granted werden, ohne damit Schindluder getrieben werden kann (weil das an der API verhindert werden kann)
+
+| Kriterium \ Relations ...                     | 1. ersetzen | 2. direkt aktualisieren | 3. via Partner aktualisieren |
+|-----------------------------------------------|------------:|------------------------:|-----------------------------:|
+| **Technische und Aufwands-Kriterien**         |             |                         |                              |
+| Beibehaltung der API vs. Umbau (inkl. Risiko) |          +2 |                      -2 |                           +1 |
+| Anwendbarkeit auf Partner- und Debitor-Person |             |                      +1 |                              |
+| Anwendbarkeit auf abhängige Relations         |          -3 |                         |                              |
+| Performance bei vielen abhängigen Relations   |          -1 |                         |                              |
+| Aufwand für explizite Grants                  |          -1 |                         |                              |
+| **Zwischenergebnis**                          |      **-3** |                  **-1** |                       **+1** |
+|                                               |             |                         |                              |
+| **Fachliche Kriterien**                       |             |                         |                              |
+| Kongruenz von Fachlichkeit+API                |          +1 |                      -1 |                           +1 |
+| Einheitlichkeit/Generizität der API           |             |                      +1 |                              |
+| UPDATE Permission für Relation-AGENT möglich  |          +1 |                         |                           +1 |
+| **Zwischenergebnis**                          |      **+2** |                   **0** |                       **+2** |
+|                                               |             |                         |                              |
+| **Endergebnis**                               |      **-1** |                  **-1** |                       **+3** |
diff --git a/doc/adr/2025-02-27-exchanging-the-partner-person.en.md b/doc/adr/2025-02-27-exchanging-the-partner-person.en.md
new file mode 100644
index 00000000..79269b29
--- /dev/null
+++ b/doc/adr/2025-02-27-exchanging-the-partner-person.en.md
@@ -0,0 +1,124 @@
+# Changing a Business Partner or Invoice Recipient (Debitor)
+
+**Status:**
+- [x] Proposed by (Michael Hönnig)
+- [ ] Accepted by (...)
+- [ ] Rejected by (...)
+- [ ] Replaced by (replacing ADR)
+
+## Context and Problem Statement
+
+In the given data model of business partners and invoice recipients (debitors), which also includes business roles such as representative, technical contacts, or mailing list subscriptions, the question arises of how to efficiently and consistently implement a change of the business partner person. These business roles are each linked to the partner person.
+
+A concrete example is changing from a natural person who has passed away to their heir community.
+**It has been shown that handling the API is complex and error-prone due to the large number of newly created objects and their links. Additionally, not all changes can be carried out in a single transaction, which can lead to inconsistencies.**
+
+The following elements must be updated:
+
+1. All relations with the old partner person:
+    - The PARTNER relation
+    - The DEBITOR relations (possibly multiple)
+    - The OPERATIONS relations (possibly multiple)
+    - The SUBSCRIBER relations (possibly multiple)
+    - The REPRESENTATIVE relations (possibly multiple)
+    - etc.
+2. The PARTNER relation has the peculiarity that it is referenced by the partner and therefore must also be replaced there.
+3. The DEBITOR relation has the peculiarity that it is referenced by the debitor and therefore must also be replaced there.
+
+As a result, as many of these *rewirings* as possible should be done in the backend.
+A central point is needed to trigger this cascade.
+
+Currently, there are three possible approaches to implementing this change dynamically, each with different impacts on effort, API, and access rights.
+
+### Technical Background
+
+At the time of this ADR's creation, the following relevant entities exist:
+- **Person**: A natural or legal entity (name, company, salutation, etc.)
+- **Contact**: Contact data of a business role
+- **Relation**: A relationship from one person (Holder) to another (Anchor), with a type (e.g., PARTNER, DEBITOR, REPRESENTATIVE) and contact data
+- **Partner**: Essentially additional data of a PARTNER relation (currently only the partner number), linking a partner person to the Hostsharing person
+- **Debitor**: Essentially additional data of a DEBITOR relation, linking a debitor person to a partner person
+
+Access rights are managed through a hierarchical, dynamic RBAC system, where the **OWNER** of an entity instance has all rights, **ADMIN** can update defined fields, **AGENT** can create links, and **TENANT**, **GUEST**, and **REFERRER** have read-only access.
+Partners and debitors use the RBAC roles of the associated relations.
+
+## Considered Alternatives
+
+* **1. Replace Relations:** Replace PARTNER/DEBITOR/OPERATIONS/... relations with a new relation for the new partner person (e.g., heir community) as the new Holder via PATCH on /api/hs/office/partners/UUID
+* **2. Directly Update Relations:** Change the Holder reference in the existing PARTNER relation to the new partner person (e.g., heir community) via PATCH on /api/hs/office/relations/UUID
+* **3. Update Relations via Partner:** Change the partner person in the PARTNER relation via PATCH on /api/hs/office/partners/UUID
+
+### Option 1: Replace Relations
+
+The exchange of the partner (and debitor) person is done by creating a new PARTNER or DEBITOR relation, and then updating the reference in the partner or debitor to point to the new relation instead of the old one.
+
+#### Advantages
+
+- **Preserving the API:** This behavior is already implemented and requires no major API remodelling, only an extension to swap additional relations.
+- **UPDATE permission for AGENT:** The AGENT role of a relation could be granted UPDATE rights because only the non-critical contact reference would be modifiable.
+- **Congruence of business logic and API:** Conceptually, this aligns with replacing the partner person, though technically, a new PARTNER relation is created instead of directly replacing the person.
+
+#### Disadvantages
+
+- **Loss of explicit GRANTs:** Explicit GRANTs on the PARTNER relation would be lost due to the relation being replaced. Preserving these would require additional implementation effort.
+- **Mismatch between business logic and API:** The exchange of the partner person would not directly occur at the partner but rather through a new PARTNER relation.
+- **Not applicable to dependent relations:** Updating dependent relations (e.g., representatives, operational contacts, billing contacts, mailing list subscriptions) would require creating new relations and deleting old ones, again leading to the loss of explicit GRANTs.
+- **Performance issues with many dependent relations:** Dependent relations can only be exchanged via loops rather than direct SQL UPDATEs, leading to poorer performance.
+
+### Option 2: Directly Update Relations
+
+The existing PARTNER relation remains unchanged, and the Holder is switched from the deceased person to the heir community.
+
+#### Advantages
+
+- **Applicability to both partner and debitor persons:** This approach would work for both partner and debitor persons at a generic level.
+- **API uniformity and generality:** REST API changes would belong uniformly to the relation endpoint, consistent with how contact changes are currently handled.
+
+#### Disadvantages
+
+- **UPDATE permission for relation-AGENT would be problematic:** The relation-AGENT must not have permission to swap the Holder. Since there are no column-specific update rights, they would also lose the ability to change the Contact.
+- **API remodelling:** The exchange of a partner person would move from the partner endpoint (/api/hs/office/partner) to the relation endpoint, requiring significant restructuring, including tests.
+- **Mismatch between business logic and API:** Although conceptually it involves replacing a partner person, technically, the change would occur at the PARTNER relation.
+
+### Option 3: Update Relations via Partner
+
+The partner (or debitor) person would still be updated at the partner or debitor level, but instead of creating a new relation, the reference to the person would be updated in the existing PARTNER (or DEBITOR) relation. Dependent relations could be updated efficiently via SQL UPDATE.
+
+#### Advantages
+
+- **Preserving the API:** The endpoint /api/hs/office/partners/UUID remains unchanged, requiring only internal adjustments.
+- **UPDATE permission for AGENT:** AGENT roles could be granted UPDATE rights, while API controls could limit modifications.
+- **Congruence of business logic and API:** The technical implementation matches the conceptual model of replacing a partner person.
+
+#### Disadvantages
+
+No significant drawbacks were identified, other than allowing UPDATE permissions on relations while controlling updates at the API level.
+
+## Decision and Outcome
+
+**Decision:** 3. Update Relations via Partner
+
+**Rationale:**
+- The API accurately reflects the business logic (PATCH partner person on /api/hs/office/partners/UUID)
+- The effort required is relatively low (many updates can be done via SQL UPDATEs)
+- UPDATE permission can be granted to relation-AGENT without security risks (since the API controls access)
+
+  | Criteria \ Relations ...                       | 1. Replace | 2. Directly Update | 3. Update via Partner |
+  |------------------------------------------------|-----------:|-------------------:|----------------------:|
+  | **Technical and Effort Criteria**              |            |                    |                       |
+  | Preserve API vs. Remodelling (incl. risk)      |         +2 |                 -2 |                    +1 |
+  | Applicability to Partner and Debitor Person    |            |                 +1 |                       |
+  | Applicability to dependent relations           |         -3 |                    |                       |
+  | Performance with many dependent relations      |         -1 |                    |                       |
+  | Effort for explicit grants                     |         -1 |                    |                       |
+  | **Intermediate Score**                         |     **-3** |             **-1** |                **+1** |
+  |                                                |            |                    |                       |
+  | **Business Criteria**                          |            |                    |                       |
+  | Congruence of Business Logic and API           |         +1 |                 -1 |                    +1 |
+  | Uniformity/Generality of the API               |            |                 +1 |                       |
+  | UPDATE Permission for Relation-AGENT possible  |         +1 |                    |                    +1 |
+  | **Intermediate Score**                         |     **+2** |              **0** |                **+2** |
+  |                                                |            |                    |                       |
+  | **Final Score**                                |     **-1** |             **-1** |                **+3** |
+
+
diff --git a/src/main/java/net/hostsharing/hsadminng/hs/office/contact/HsOfficeContactController.java b/src/main/java/net/hostsharing/hsadminng/hs/office/contact/HsOfficeContactController.java
index 0a041763..bf8a9c09 100644
--- a/src/main/java/net/hostsharing/hsadminng/hs/office/contact/HsOfficeContactController.java
+++ b/src/main/java/net/hostsharing/hsadminng/hs/office/contact/HsOfficeContactController.java
@@ -13,15 +13,13 @@ import org.springframework.transaction.annotation.Transactional;
 import org.springframework.web.bind.annotation.RestController;
 import org.springframework.web.servlet.mvc.method.annotation.MvcUriComponentsBuilder;
 
+import jakarta.annotation.PostConstruct;
 import java.util.List;
 import java.util.UUID;
-import java.util.function.BiConsumer;
 
 import static net.hostsharing.hsadminng.errors.Validate.validate;
-import static net.hostsharing.hsadminng.mapper.KeyValueMap.from;
 
 @RestController
-
 public class HsOfficeContactController implements HsOfficeContactsApi {
 
     @Autowired
@@ -30,9 +28,20 @@ public class HsOfficeContactController implements HsOfficeContactsApi {
     @Autowired
     private StrictMapper mapper;
 
+    @Autowired
+    private HsOfficeContactFromResourceConverter<HsOfficeContactRbacEntity> contactFromResourceConverter;
+
     @Autowired
     private HsOfficeContactRbacRepository contactRepo;
 
+    @PostConstruct
+    public void init() {
+        // HOWTO: add a ModelMapper converter for a generic entity class to a ModelMapper to be used in a certain context
+        //  This @PostConstruct could be implemented in the converter, but only without generics.
+        //  But this converter is for HsOfficeContactRbacEntity and HsOfficeContactRealEntity.
+        mapper.addConverter(contactFromResourceConverter, HsOfficeContactInsertResource.class, HsOfficeContactRbacEntity.class);
+    }
+
     @Override
     @Transactional(readOnly = true)
     @Timed("app.office.contacts.api.getListOfContacts")
@@ -62,7 +71,7 @@ public class HsOfficeContactController implements HsOfficeContactsApi {
 
         context.define(currentSubject, assumedRoles);
 
-        final var entityToSave = mapper.map(body, HsOfficeContactRbacEntity.class, RESOURCE_TO_ENTITY_POSTMAPPER);
+        final var entityToSave = mapper.map(body, HsOfficeContactRbacEntity.class);
 
         final var saved = contactRepo.save(entityToSave);
 
@@ -128,11 +137,4 @@ public class HsOfficeContactController implements HsOfficeContactsApi {
         final var mapped = mapper.map(saved, HsOfficeContactResource.class);
         return ResponseEntity.ok(mapped);
     }
-
-    @SuppressWarnings("unchecked")
-    final BiConsumer<HsOfficeContactInsertResource, HsOfficeContactRbacEntity> RESOURCE_TO_ENTITY_POSTMAPPER = (resource, entity) -> {
-        entity.putPostalAddress(from(resource.getPostalAddress()));
-        entity.putEmailAddresses(from(resource.getEmailAddresses()));
-        entity.putPhoneNumbers(from(resource.getPhoneNumbers()));
-    };
 }
diff --git a/src/main/java/net/hostsharing/hsadminng/hs/office/contact/HsOfficeContactFromResourceConverter.java b/src/main/java/net/hostsharing/hsadminng/hs/office/contact/HsOfficeContactFromResourceConverter.java
new file mode 100644
index 00000000..8ebcbc88
--- /dev/null
+++ b/src/main/java/net/hostsharing/hsadminng/hs/office/contact/HsOfficeContactFromResourceConverter.java
@@ -0,0 +1,27 @@
+package net.hostsharing.hsadminng.hs.office.contact;
+
+import lombok.SneakyThrows;
+import net.hostsharing.hsadminng.hs.office.generated.api.v1.model.HsOfficeContactInsertResource;
+import org.modelmapper.Converter;
+import org.modelmapper.spi.MappingContext;
+import org.springframework.stereotype.Component;
+
+import static net.hostsharing.hsadminng.mapper.KeyValueMap.from;
+
+// HOWTO: implement a ModelMapper converter which converts from a (JSON) resource instance to a generic entity instance (RBAC vs. REAL)
+@Component
+public class HsOfficeContactFromResourceConverter<E extends HsOfficeContact>
+        implements Converter<HsOfficeContactInsertResource, E> {
+
+    @Override
+    @SneakyThrows
+    public E convert(final MappingContext<HsOfficeContactInsertResource, E> context) {
+        final var resource = context.getSource();
+        final var entity = context.getDestinationType().getDeclaredConstructor().newInstance();
+        entity.setCaption(resource.getCaption());
+        entity.putPostalAddress(from(resource.getPostalAddress()));
+        entity.putEmailAddresses(from(resource.getEmailAddresses()));
+        entity.putPhoneNumbers(from(resource.getPhoneNumbers()));
+        return entity;
+    }
+}
diff --git a/src/main/java/net/hostsharing/hsadminng/hs/office/partner/HsOfficePartnerController.java b/src/main/java/net/hostsharing/hsadminng/hs/office/partner/HsOfficePartnerController.java
index aa8b572e..6074c909 100644
--- a/src/main/java/net/hostsharing/hsadminng/hs/office/partner/HsOfficePartnerController.java
+++ b/src/main/java/net/hostsharing/hsadminng/hs/office/partner/HsOfficePartnerController.java
@@ -3,8 +3,10 @@ package net.hostsharing.hsadminng.hs.office.partner;
 import io.micrometer.core.annotation.Timed;
 import net.hostsharing.hsadminng.context.Context;
 import net.hostsharing.hsadminng.errors.ReferenceNotFoundException;
+import net.hostsharing.hsadminng.hs.office.contact.HsOfficeContactFromResourceConverter;
 import net.hostsharing.hsadminng.hs.office.contact.HsOfficeContactRealEntity;
 import net.hostsharing.hsadminng.hs.office.generated.api.v1.api.HsOfficePartnersApi;
+import net.hostsharing.hsadminng.hs.office.generated.api.v1.model.HsOfficeContactInsertResource;
 import net.hostsharing.hsadminng.hs.office.generated.api.v1.model.HsOfficePartnerInsertResource;
 import net.hostsharing.hsadminng.hs.office.generated.api.v1.model.HsOfficePartnerPatchResource;
 import net.hostsharing.hsadminng.hs.office.generated.api.v1.model.HsOfficePartnerResource;
@@ -22,6 +24,7 @@ import org.springframework.transaction.annotation.Transactional;
 import org.springframework.web.bind.annotation.RestController;
 import org.springframework.web.servlet.mvc.method.annotation.MvcUriComponentsBuilder;
 
+import jakarta.annotation.PostConstruct;
 import jakarta.persistence.EntityManager;
 import jakarta.persistence.PersistenceContext;
 import java.util.List;
@@ -42,14 +45,22 @@ public class HsOfficePartnerController implements HsOfficePartnersApi {
     private StrictMapper mapper;
 
     @Autowired
-    private HsOfficePartnerRbacRepository partnerRepo;
+    private HsOfficeContactFromResourceConverter<HsOfficeContactRealEntity> contactFromResourceConverter;
 
     @Autowired
-    private HsOfficeRelationRealRepository relationRepo;
+    private HsOfficePartnerRbacRepository rbacPartnerRepo;
+
+    @Autowired
+    private HsOfficeRelationRealRepository realRelationRepo;
 
     @PersistenceContext
     private EntityManager em;
 
+    @PostConstruct
+    public void init() {
+        mapper.addConverter(contactFromResourceConverter, HsOfficeContactInsertResource.class, HsOfficeContactRealEntity.class);
+    }
+
     @Override
     @Transactional(readOnly = true)
     @Timed("app.office.partners.api.getListOfPartners")
@@ -59,7 +70,7 @@ public class HsOfficePartnerController implements HsOfficePartnersApi {
             final String name) {
         context.define(currentSubject, assumedRoles);
 
-        final var entities = partnerRepo.findPartnerByOptionalNameLike(name);
+        final var entities = rbacPartnerRepo.findPartnerByOptionalNameLike(name);
 
         final var resources = mapper.mapList(entities, HsOfficePartnerResource.class, ENTITY_TO_RESOURCE_POSTMAPPER);
         return ResponseEntity.ok(resources);
@@ -77,7 +88,7 @@ public class HsOfficePartnerController implements HsOfficePartnersApi {
 
         final var entityToSave = createPartnerEntity(body);
 
-        final var saved = partnerRepo.save(entityToSave);
+        final var saved = rbacPartnerRepo.save(entityToSave);
 
         final var uri =
                 MvcUriComponentsBuilder.fromController(getClass())
@@ -98,7 +109,7 @@ public class HsOfficePartnerController implements HsOfficePartnersApi {
 
         context.define(currentSubject, assumedRoles);
 
-        final var result = partnerRepo.findByUuid(partnerUuid);
+        final var result = rbacPartnerRepo.findByUuid(partnerUuid);
         if (result.isEmpty()) {
             return ResponseEntity.notFound().build();
         }
@@ -116,7 +127,7 @@ public class HsOfficePartnerController implements HsOfficePartnersApi {
 
         context.define(currentSubject, assumedRoles);
 
-        final var result = partnerRepo.findPartnerByPartnerNumber(partnerNumber);
+        final var result = rbacPartnerRepo.findPartnerByPartnerNumber(partnerNumber);
         if (result.isEmpty()) {
             return ResponseEntity.notFound().build();
         }
@@ -133,12 +144,12 @@ public class HsOfficePartnerController implements HsOfficePartnersApi {
             final UUID partnerUuid) {
         context.define(currentSubject, assumedRoles);
 
-        final var partnerToDelete = partnerRepo.findByUuid(partnerUuid);
+        final var partnerToDelete = rbacPartnerRepo.findByUuid(partnerUuid);
         if (partnerToDelete.isEmpty()) {
             return ResponseEntity.notFound().build();
         }
 
-        if (partnerRepo.deleteByUuid(partnerUuid) != 1) {
+        if (rbacPartnerRepo.deleteByUuid(partnerUuid) != 1) {
             return ResponseEntity.status(HttpStatus.FORBIDDEN).build();
         }
 
@@ -156,22 +167,55 @@ public class HsOfficePartnerController implements HsOfficePartnersApi {
 
         context.define(currentSubject, assumedRoles);
 
-        final var current = partnerRepo.findByUuid(partnerUuid).orElseThrow();
-        final var previousPartnerRel = current.getPartnerRel();
+        final var current = rbacPartnerRepo.findByUuid(partnerUuid).orElseThrow();
+        final var previousPartnerPerson = current.getPartnerRel().getHolder();
 
-        new HsOfficePartnerEntityPatcher(em, current).apply(body);
+        new HsOfficePartnerEntityPatcher(mapper, em, current).apply(body);
 
-        final var saved = partnerRepo.save(current);
-        optionallyCreateExPartnerRelation(saved, previousPartnerRel);
+        final var saved = rbacPartnerRepo.save(current);
+        optionallyCreateExPartnerRelation(saved, previousPartnerPerson);
+        optionallyUpdateRelatedRelations(saved, previousPartnerPerson);
 
         final var mapped = mapper.map(saved, HsOfficePartnerResource.class, ENTITY_TO_RESOURCE_POSTMAPPER);
         return ResponseEntity.ok(mapped);
     }
 
-    private void optionallyCreateExPartnerRelation(final HsOfficePartnerRbacEntity saved, final HsOfficeRelationRealEntity previousPartnerRel) {
-        if (!saved.getPartnerRel().getUuid().equals(previousPartnerRel.getUuid())) {
-            // TODO.impl: we also need to use the new partner-person as the anchor
-            relationRepo.save(previousPartnerRel.toBuilder().uuid(null).type(EX_PARTNER).build());
+    private void optionallyCreateExPartnerRelation(final HsOfficePartnerRbacEntity saved, final HsOfficePersonRealEntity previousPartnerPerson) {
+
+        final var partnerPersonHasChanged = !saved.getPartnerRel().getHolder().getUuid().equals(previousPartnerPerson.getUuid());
+        if (partnerPersonHasChanged) {
+            realRelationRepo.save(saved.getPartnerRel().toBuilder()
+                    .uuid(null)
+                    .type(EX_PARTNER)
+                    .anchor(saved.getPartnerRel().getHolder())
+                    .holder(previousPartnerPerson)
+                    .build());
+        }
+    }
+
+    private void optionallyUpdateRelatedRelations(final HsOfficePartnerRbacEntity saved, final HsOfficePersonRealEntity previousPartnerPerson) {
+        final var partnerPersonHasChanged = !saved.getPartnerRel().getHolder().getUuid().equals(previousPartnerPerson.getUuid());
+        if (partnerPersonHasChanged) {
+            // self-debitors of the old partner-person become self-debitors of the new partner person
+            em.createNativeQuery("""
+                UPDATE hs_office.relation
+                    SET holderUuid = :newPartnerPersonUuid
+                    WHERE type = 'DEBITOR' AND
+                          holderUuid = :oldPartnerPersonUuid AND anchorUuid = :oldPartnerPersonUuid
+            """)
+                    .setParameter("oldPartnerPersonUuid", previousPartnerPerson.getUuid())
+                    .setParameter("newPartnerPersonUuid", saved.getPartnerRel().getHolder().getUuid())
+                    .executeUpdate();
+
+            // re-anchor all relations from the old partner person to the new partner persion
+            em.createNativeQuery("""
+                UPDATE hs_office.relation
+                    SET anchorUuid = :newPartnerPersonUuid
+                    WHERE anchorUuid = :oldPartnerPersonUuid
+            """)
+                    .setParameter("oldPartnerPersonUuid", previousPartnerPerson.getUuid())
+                    .setParameter("newPartnerPersonUuid", saved.getPartnerRel().getHolder().getUuid())
+                    .executeUpdate();
         }
     }
 
diff --git a/src/main/java/net/hostsharing/hsadminng/hs/office/partner/HsOfficePartnerEntityPatcher.java b/src/main/java/net/hostsharing/hsadminng/hs/office/partner/HsOfficePartnerEntityPatcher.java
index ecf8adc9..5c176f93 100644
--- a/src/main/java/net/hostsharing/hsadminng/hs/office/partner/HsOfficePartnerEntityPatcher.java
+++ b/src/main/java/net/hostsharing/hsadminng/hs/office/partner/HsOfficePartnerEntityPatcher.java
@@ -1,35 +1,36 @@
 package net.hostsharing.hsadminng.hs.office.partner;
 
 import net.hostsharing.hsadminng.hs.office.generated.api.v1.model.HsOfficePartnerPatchResource;
-import net.hostsharing.hsadminng.hs.office.relation.HsOfficeRelationRealEntity;
+import net.hostsharing.hsadminng.hs.office.relation.HsOfficeRelationPatcher;
 import net.hostsharing.hsadminng.mapper.EntityPatcher;
-import net.hostsharing.hsadminng.mapper.OptionalFromJson;
+import net.hostsharing.hsadminng.mapper.StrictMapper;
 
 import jakarta.persistence.EntityManager;
 
 class HsOfficePartnerEntityPatcher implements EntityPatcher<HsOfficePartnerPatchResource> {
+
+    private final StrictMapper mapper;
     private final EntityManager em;
     private final HsOfficePartnerRbacEntity entity;
+
     HsOfficePartnerEntityPatcher(
+            final StrictMapper mapper,
             final EntityManager em,
             final HsOfficePartnerRbacEntity entity) {
+        this.mapper = mapper;
         this.em = em;
         this.entity = entity;
     }
 
     @Override
     public void apply(final HsOfficePartnerPatchResource resource) {
-        OptionalFromJson.of(resource.getPartnerRelUuid()).ifPresent(newValue -> {
-            verifyNotNull(newValue, "partnerRel");
-            entity.setPartnerRel(em.getReference(HsOfficeRelationRealEntity.class, newValue));
-        });
 
-        new HsOfficePartnerDetailsEntityPatcher(em, entity.getDetails()).apply(resource.getDetails());
-    }
+        if (resource.getPartnerRel() != null) {
+            new HsOfficeRelationPatcher(mapper, em, entity.getPartnerRel()).apply(resource.getPartnerRel());
+        }
 
-    private void verifyNotNull(final Object newValue, final String propertyName) {
-        if (newValue == null) {
-            throw new IllegalArgumentException("property '" + propertyName + "' must not be null");
+        if (resource.getDetails() != null) {
+            new HsOfficePartnerDetailsEntityPatcher(em, entity.getDetails()).apply(resource.getDetails());
         }
     }
 }
diff --git a/src/main/java/net/hostsharing/hsadminng/hs/office/relation/HsOfficeRelationController.java b/src/main/java/net/hostsharing/hsadminng/hs/office/relation/HsOfficeRelationController.java
index 4a92bd7f..53e2712b 100644
--- a/src/main/java/net/hostsharing/hsadminng/hs/office/relation/HsOfficeRelationController.java
+++ b/src/main/java/net/hostsharing/hsadminng/hs/office/relation/HsOfficeRelationController.java
@@ -163,13 +163,13 @@ public class HsOfficeRelationController implements HsOfficeRelationsApi {
             final String currentSubject,
             final String assumedRoles,
             final UUID relationUuid,
-            final HsOfficeRelationPatchResource body) {
+            final HsOfficeRelationContactPatchResource body) {
 
         context.define(currentSubject, assumedRoles);
 
         final var current = rbacRelationRepo.findByUuid(relationUuid).orElseThrow();
 
-        new HsOfficeRelationEntityPatcher(em, current).apply(body);
+        new HsOfficeRelationEntityContactPatcher(em, current).apply(body);
 
         final var saved = rbacRelationRepo.save(current);
         final var mapped = mapper.map(saved, HsOfficeRelationResource.class);
diff --git a/src/main/java/net/hostsharing/hsadminng/hs/office/relation/HsOfficeRelationEntityPatcher.java b/src/main/java/net/hostsharing/hsadminng/hs/office/relation/HsOfficeRelationEntityContactPatcher.java
similarity index 74%
rename from src/main/java/net/hostsharing/hsadminng/hs/office/relation/HsOfficeRelationEntityPatcher.java
rename to src/main/java/net/hostsharing/hsadminng/hs/office/relation/HsOfficeRelationEntityContactPatcher.java
index d9e6244a..c01ab209 100644
--- a/src/main/java/net/hostsharing/hsadminng/hs/office/relation/HsOfficeRelationEntityPatcher.java
+++ b/src/main/java/net/hostsharing/hsadminng/hs/office/relation/HsOfficeRelationEntityContactPatcher.java
@@ -1,25 +1,25 @@
 package net.hostsharing.hsadminng.hs.office.relation;
 
 import net.hostsharing.hsadminng.hs.office.contact.HsOfficeContactRealEntity;
-import net.hostsharing.hsadminng.hs.office.generated.api.v1.model.HsOfficeRelationPatchResource;
+import net.hostsharing.hsadminng.hs.office.generated.api.v1.model.HsOfficeRelationContactPatchResource;
 import net.hostsharing.hsadminng.mapper.EntityPatcher;
 import net.hostsharing.hsadminng.mapper.OptionalFromJson;
 
 import jakarta.persistence.EntityManager;
 import java.util.UUID;
 
-class HsOfficeRelationEntityPatcher implements EntityPatcher<HsOfficeRelationPatchResource> {
+public class HsOfficeRelationEntityContactPatcher implements EntityPatcher<HsOfficeRelationContactPatchResource> {
 
     private final EntityManager em;
     private final HsOfficeRelation entity;
 
-    HsOfficeRelationEntityPatcher(final EntityManager em, final HsOfficeRelation entity) {
+    public HsOfficeRelationEntityContactPatcher(final EntityManager em, final HsOfficeRelation entity) {
         this.em = em;
         this.entity = entity;
     }
 
     @Override
-    public void apply(final HsOfficeRelationPatchResource resource) {
+    public void apply(final HsOfficeRelationContactPatchResource resource) {
         OptionalFromJson.of(resource.getContactUuid()).ifPresent(newValue -> {
             verifyNotNull(newValue, "contact");
             entity.setContact(em.getReference(HsOfficeContactRealEntity.class, newValue));
diff --git a/src/main/java/net/hostsharing/hsadminng/hs/office/relation/HsOfficeRelationPatcher.java b/src/main/java/net/hostsharing/hsadminng/hs/office/relation/HsOfficeRelationPatcher.java
new file mode 100644
index 00000000..1111059b
--- /dev/null
+++ b/src/main/java/net/hostsharing/hsadminng/hs/office/relation/HsOfficeRelationPatcher.java
@@ -0,0 +1,50 @@
+package net.hostsharing.hsadminng.hs.office.relation;
+
+import net.hostsharing.hsadminng.hs.office.contact.HsOfficeContactRealEntity;
+import net.hostsharing.hsadminng.hs.office.generated.api.v1.model.HsOfficeRelationPatchResource;
+import net.hostsharing.hsadminng.hs.office.person.HsOfficePersonRealEntity;
+import net.hostsharing.hsadminng.mapper.EntityPatcher;
+import net.hostsharing.hsadminng.mapper.StrictMapper;
+
+import jakarta.persistence.EntityManager;
+import jakarta.validation.ValidationException;
+
+public class HsOfficeRelationPatcher implements EntityPatcher<HsOfficeRelationPatchResource> {
+
+    private final StrictMapper mapper;
+    private final EntityManager em;
+    private final HsOfficeRelation entity;
+
+    public HsOfficeRelationPatcher(final StrictMapper mapper, final EntityManager em, final HsOfficeRelation entity) {
+        this.mapper = mapper;
+        this.em = em;
+        this.entity = entity;
+    }
+
+    @Override
+    public void apply(final HsOfficeRelationPatchResource resource) {
+        if (resource.getHolder() != null && resource.getHolderUuid() != null) {
+            throw new ValidationException("either \"holder\" or \"holder.uuid\" can be given, not both");
+        } else {
+            if (resource.getHolder() != null) {
+                final var newHolder = mapper.map(resource.getHolder(), HsOfficePersonRealEntity.class);
+                em.persist(newHolder);
+                entity.setHolder(newHolder);
+            } else if (resource.getHolderUuid() != null) {
+                entity.setHolder(em.getReference(HsOfficePersonRealEntity.class, resource.getHolderUuid().get()));
+            }
+        }
+
+        if (resource.getContact() != null && resource.getContactUuid() != null) {
+            throw new ValidationException("either \"contact\" or \"contact.uuid\" can be given, not both");
+        } else {
+            if (resource.getContact() != null) {
+                final var newContact = mapper.map(resource.getContact(), HsOfficeContactRealEntity.class);
+                em.persist(newContact);
+                entity.setContact(newContact);
+            } else if (resource.getContactUuid() != null) {
+                entity.setContact(em.getReference(HsOfficeContactRealEntity.class, resource.getContactUuid().get()));
+            }
+        }
+    }
+}
diff --git a/src/main/java/net/hostsharing/hsadminng/hs/office/relation/HsOfficeRelationRbacEntity.java b/src/main/java/net/hostsharing/hsadminng/hs/office/relation/HsOfficeRelationRbacEntity.java
index c0f8476f..d1f43923 100644
--- a/src/main/java/net/hostsharing/hsadminng/hs/office/relation/HsOfficeRelationRbacEntity.java
+++ b/src/main/java/net/hostsharing/hsadminng/hs/office/relation/HsOfficeRelationRbacEntity.java
@@ -51,7 +51,7 @@ public class HsOfficeRelationRbacEntity extends HsOfficeRelation {
                         """))
                 .withRestrictedViewOrderBy(SQL.expression(
                         "(select idName from hs_office.person_iv p where p.uuid = target.holderUuid)"))
-                .withUpdatableColumns("contactUuid")
+                .withUpdatableColumns("anchorUuid", "holderUuid", "contactUuid") // BEWARE: additional checks at API-level
                 .importEntityAlias("anchorPerson", HsOfficePersonRbacEntity.class, usingDefaultCase(),
                         dependsOnColumn("anchorUuid"),
                         directlyFetchedByDependsOnColumn(),
diff --git a/src/main/resources/api-definition/hs-office/hs-office-partner-schemas.yaml b/src/main/resources/api-definition/hs-office/hs-office-partner-schemas.yaml
index 727c5b61..88b6fd06 100644
--- a/src/main/resources/api-definition/hs-office/hs-office-partner-schemas.yaml
+++ b/src/main/resources/api-definition/hs-office/hs-office-partner-schemas.yaml
@@ -48,12 +48,11 @@ components:
         HsOfficePartnerPatch:
             type: object
             properties:
-                partnerRel.uuid:
-                    type: string
-                    format: uuid
-                    nullable: true
+                partnerRel:
+                    $ref: 'hs-office-relation-schemas.yaml#/components/schemas/HsOfficeRelationPatch'
                 details:
                     $ref: '#/components/schemas/HsOfficePartnerDetailsPatch'
+            additionalProperties: false
 
         HsOfficePartnerDetailsPatch:
             type: object
diff --git a/src/main/resources/api-definition/hs-office/hs-office-relation-schemas.yaml b/src/main/resources/api-definition/hs-office/hs-office-relation-schemas.yaml
index 9b8d2e46..96865955 100644
--- a/src/main/resources/api-definition/hs-office/hs-office-relation-schemas.yaml
+++ b/src/main/resources/api-definition/hs-office/hs-office-relation-schemas.yaml
@@ -34,7 +34,7 @@ components:
                 contact:
                     $ref: 'hs-office-contact-schemas.yaml#/components/schemas/HsOfficeContact'
 
-        HsOfficeRelationPatch:
+        HsOfficeRelationContactPatch:
             type: object
             properties:
                 contact.uuid:
@@ -42,6 +42,27 @@ components:
                     format: uuid
                     nullable: true
 
+        HsOfficeRelationPatch:
+            type: object
+            properties:
+                anchor.uuid:
+                    type: string
+                    format: uuid
+                    nullable: true
+                holder.uuid:
+                    type: string
+                    format: uuid
+                    nullable: true
+                holder:
+                    $ref: 'hs-office-person-schemas.yaml#/components/schemas/HsOfficePersonInsert'
+                contact.uuid:
+                    type: string
+                    format: uuid
+                    nullable: true
+                contact:
+                    $ref: 'hs-office-contact-schemas.yaml#/components/schemas/HsOfficeContactInsert'
+            additionalProperties: false
+
         # arbitrary relation with explicit type
         HsOfficeRelationInsert:
             type: object
diff --git a/src/main/resources/api-definition/hs-office/hs-office-relations-with-uuid.yaml b/src/main/resources/api-definition/hs-office/hs-office-relations-with-uuid.yaml
index b492f322..b49902cf 100644
--- a/src/main/resources/api-definition/hs-office/hs-office-relations-with-uuid.yaml
+++ b/src/main/resources/api-definition/hs-office/hs-office-relations-with-uuid.yaml
@@ -44,7 +44,7 @@ patch:
         content:
             'application/json':
                 schema:
-                    $ref: 'hs-office-relation-schemas.yaml#/components/schemas/HsOfficeRelationPatch'
+                    $ref: 'hs-office-relation-schemas.yaml#/components/schemas/HsOfficeRelationContactPatch'
     responses:
         "200":
             description: OK
diff --git a/src/main/resources/db/changelog/5-hs-office/503-relation/5033-hs-office-relation-rbac.sql b/src/main/resources/db/changelog/5-hs-office/503-relation/5033-hs-office-relation-rbac.sql
index 260391bf..8e1507d4 100644
--- a/src/main/resources/db/changelog/5-hs-office/503-relation/5033-hs-office-relation-rbac.sql
+++ b/src/main/resources/db/changelog/5-hs-office/503-relation/5033-hs-office-relation-rbac.sql
@@ -124,7 +124,9 @@ create or replace procedure hs_office.relation_update_rbac_system(
     language plpgsql as $$
 begin
 
-    if NEW.contactUuid is distinct from OLD.contactUuid then
+    if NEW.holderUuid is distinct from OLD.holderUuid
+    or NEW.anchorUuid is distinct from OLD.anchorUuid
+    or NEW.contactUuid is distinct from OLD.contactUuid then
         delete from rbac.grant g where g.grantedbytriggerof = OLD.uuid;
         call hs_office.relation_build_rbac_system(NEW);
     end if;
@@ -248,6 +250,8 @@ call rbac.generateRbacRestrictedView('hs_office.relation',
         (select idName from hs_office.person_iv p where p.uuid = target.holderUuid)
     $orderBy$,
     $updates$
+        anchorUuid = new.anchorUuid,
+        holderUuid = new.holderUuid,
         contactUuid = new.contactUuid
     $updates$);
 --//
diff --git a/src/test/java/net/hostsharing/hsadminng/arch/ArchitectureTest.java b/src/test/java/net/hostsharing/hsadminng/arch/ArchitectureTest.java
index 2bf87f09..664b803c 100644
--- a/src/test/java/net/hostsharing/hsadminng/arch/ArchitectureTest.java
+++ b/src/test/java/net/hostsharing/hsadminng/arch/ArchitectureTest.java
@@ -20,6 +20,7 @@ import org.springframework.boot.test.context.SpringBootTest;
 import org.springframework.data.repository.Repository;
 import org.springframework.web.bind.annotation.RestController;
 
+import jakarta.annotation.PostConstruct;
 import jakarta.persistence.Table;
 
 import java.lang.annotation.Annotation;
@@ -420,7 +421,7 @@ public class ArchitectureTest {
                     if (isGeneratedSpringRepositoryMethod(item, method)) {
                         continue;
                     }
-                    if (item.isAnnotatedWith(RestController.class) && !method.getModifiers().contains(PUBLIC)) {
+                    if (!method.getModifiers().contains(PUBLIC) || method.isAnnotatedWith(PostConstruct.class)) {
                         continue;
                     }
                     final var message = String.format(
diff --git a/src/test/java/net/hostsharing/hsadminng/hs/office/partner/HsOfficePartnerControllerAcceptanceTest.java b/src/test/java/net/hostsharing/hsadminng/hs/office/partner/HsOfficePartnerControllerAcceptanceTest.java
index 7afd9714..36490dff 100644
--- a/src/test/java/net/hostsharing/hsadminng/hs/office/partner/HsOfficePartnerControllerAcceptanceTest.java
+++ b/src/test/java/net/hostsharing/hsadminng/hs/office/partner/HsOfficePartnerControllerAcceptanceTest.java
@@ -316,7 +316,7 @@ class HsOfficePartnerControllerAcceptanceTest extends ContextBasedTestWithCleanu
 
             context.define("superuser-alex@hostsharing.net");
             final var givenPartner = givenSomeTemporaryPartnerBessler(20011);
-            final var givenPartnerRel = givenSomeTemporaryPartnerRel("Winkler", "third contact");
+            final var newPartnerPerson = personRealRepo.findPersonByOptionalNameLike("Winkler").getFirst();
 
             RestAssured // @formatter:off
                 .given()
@@ -325,7 +325,9 @@ class HsOfficePartnerControllerAcceptanceTest extends ContextBasedTestWithCleanu
                     .body("""
                            {
                                "partnerNumber": "P-20011",
-                               "partnerRel.uuid": "%s",
+                               "partnerRel": {
+                                   "holder.uuid": "%s"
+                               },
                                "details": {
                                    "registrationOffice": "Temp Registergericht Aurich",
                                    "registrationNumber": "222222",
@@ -334,7 +336,7 @@ class HsOfficePartnerControllerAcceptanceTest extends ContextBasedTestWithCleanu
                                    "dateOfDeath": "2022-01-12"
                                }
                              }
-                           """.formatted(givenPartnerRel.getUuid()))
+                           """.formatted(newPartnerPerson.getUuid()))
                     .port(port)
                 .when()
                     .patch("http://localhost/api/hs/office/partners/" + givenPartner.getUuid())
@@ -348,7 +350,7 @@ class HsOfficePartnerControllerAcceptanceTest extends ContextBasedTestWithCleanu
                             "anchor": { "tradeName": "Hostsharing eG" },
                             "holder": { "familyName": "Winkler" },
                             "type": "PARTNER",
-                            "contact": { "caption": "third contact" }
+                            "contact": { "caption": "fourth contact" }
                         },
                         "details": {
                             "registrationOffice": "Temp Registergericht Aurich",
@@ -368,7 +370,7 @@ class HsOfficePartnerControllerAcceptanceTest extends ContextBasedTestWithCleanu
                     .matches(partner -> {
                         assertThat(partner.getPartnerNumber()).isEqualTo(givenPartner.getPartnerNumber());
                         assertThat(partner.getPartnerRel().getHolder().getFamilyName()).isEqualTo("Winkler");
-                        assertThat(partner.getPartnerRel().getContact().getCaption()).isEqualTo("third contact");
+                        assertThat(partner.getPartnerRel().getContact().getCaption()).isEqualTo("fourth contact");
                         assertThat(partner.getDetails().getRegistrationOffice()).isEqualTo("Temp Registergericht Aurich");
                         assertThat(partner.getDetails().getRegistrationNumber()).isEqualTo("222222");
                         assertThat(partner.getDetails().getBirthName()).isEqualTo("Maja Schmidt");
@@ -379,11 +381,11 @@ class HsOfficePartnerControllerAcceptanceTest extends ContextBasedTestWithCleanu
         }
 
         @Test
-        void patchingThePartnerRelCreatesExPartnerRel() {
+        void patchingThePartnerPersonCreatesExPartnerRel() {
 
             context.define("superuser-alex@hostsharing.net");
             final var givenPartner = givenSomeTemporaryPartnerBessler(20011);
-            final var givenPartnerRel = givenSomeTemporaryPartnerRel("Winkler", "third contact");
+            final var newPartnerPerson = personRealRepo.findPersonByOptionalNameLike("Winkler").getFirst();
 
             RestAssured // @formatter:off
                     .given()
@@ -391,9 +393,11 @@ class HsOfficePartnerControllerAcceptanceTest extends ContextBasedTestWithCleanu
                         .contentType(ContentType.JSON)
                         .body("""
                                 {
-                                   "partnerRel.uuid": "%s"
+                                   "partnerRel": {
+                                       "holder.uuid": "%s"
+                                   }
                                 }
-                                """.formatted(givenPartnerRel.getUuid()))
+                                """.formatted(newPartnerPerson.getUuid()))
                         .port(port)
                     .when()
                         .patch("http://localhost/api/hs/office/partners/" + givenPartner.getUuid())
@@ -405,16 +409,16 @@ class HsOfficePartnerControllerAcceptanceTest extends ContextBasedTestWithCleanu
             context.define("superuser-alex@hostsharing.net");
             assertThat(partnerRepo.findByUuid(givenPartner.getUuid())).isPresent().get()
                     .matches(partner -> {
-                        assertThat(partner.getPartnerRel().getHolder().getFamilyName()).isEqualTo("Winkler");
-                        assertThat(partner.getPartnerRel().getContact().getCaption()).isEqualTo("third contact");
+                        assertThat(partner.getPartnerRel().getHolder().getFamilyName()).isEqualTo("Winkler"); // updated
+                        assertThat(partner.getPartnerRel().getContact().getCaption()).isEqualTo("fourth contact"); // unchanged
                         return true;
                     });
 
             // and an ex-partner-relation got created
-            final var anchorpartnerPersonUUid = givenPartner.getPartnerRel().getAnchor().getUuid();
-            assertThat(relationRepo.findRelationRelatedToPersonUuidRelationTypeMarkPersonAndContactData(anchorpartnerPersonUUid, EX_PARTNER, null, null, null))
+            final var newPartnerPersonUuid = givenPartner.getPartnerRel().getHolder().getUuid();
+            assertThat(relationRepo.findRelationRelatedToPersonUuidRelationTypeMarkPersonAndContactData(newPartnerPersonUuid, EX_PARTNER, null, null, null))
                     .map(HsOfficeRelation::toShortString)
-                    .contains("rel(anchor='LP Hostsharing eG', type='EX_PARTNER', holder='UF Erben Bessler')");
+                    .contains("rel(anchor='NP Winkler, Paul', type='EX_PARTNER', holder='UF Erben Bessler')");
         }
 
         @Test
diff --git a/src/test/java/net/hostsharing/hsadminng/hs/office/partner/HsOfficePartnerControllerRestTest.java b/src/test/java/net/hostsharing/hsadminng/hs/office/partner/HsOfficePartnerControllerRestTest.java
index 1ed5389b..074b3580 100644
--- a/src/test/java/net/hostsharing/hsadminng/hs/office/partner/HsOfficePartnerControllerRestTest.java
+++ b/src/test/java/net/hostsharing/hsadminng/hs/office/partner/HsOfficePartnerControllerRestTest.java
@@ -1,6 +1,7 @@
 package net.hostsharing.hsadminng.hs.office.partner;
 
 import net.hostsharing.hsadminng.context.Context;
+import net.hostsharing.hsadminng.hs.office.contact.HsOfficeContactFromResourceConverter;
 import net.hostsharing.hsadminng.hs.office.contact.HsOfficeContactRbacEntity;
 import net.hostsharing.hsadminng.hs.office.person.HsOfficePersonRealEntity;
 import net.hostsharing.hsadminng.hs.office.relation.HsOfficeRelationRealEntity;
@@ -38,7 +39,7 @@ import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.
 import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
 
 @WebMvcTest(HsOfficePartnerController.class)
-@Import({StrictMapper.class, DisableSecurityConfig.class})
+@Import({ StrictMapper.class, HsOfficeContactFromResourceConverter.class, DisableSecurityConfig.class})
 @ActiveProfiles("test")
 class HsOfficePartnerControllerRestTest {
 
@@ -108,8 +109,6 @@ class HsOfficePartnerControllerRestTest {
                                              "holder.uuid": "%s",
                                              "contact.uuid": "%s"
                                         },
-                                        "person.uuid": "%s",
-                                        "contact.uuid": "%s",
                                         "details": {
                                             "registrationOffice": "Temp Registergericht Aurich",
                                             "registrationNumber": "111111"
@@ -118,8 +117,6 @@ class HsOfficePartnerControllerRestTest {
                                     """.formatted(
                                     GIVEN_MANDANTE_UUID,
                                     GIVEN_INVALID_UUID,
-                                    GIVEN_CONTACT_UUID,
-                                    GIVEN_INVALID_UUID,
                                     GIVEN_CONTACT_UUID))
                             .accept(MediaType.APPLICATION_JSON))
 
@@ -145,8 +142,6 @@ class HsOfficePartnerControllerRestTest {
                                              "holder.uuid": "%s",
                                              "contact.uuid": "%s"
                                         },
-                                        "person.uuid": "%s",
-                                        "contact.uuid": "%s",
                                         "details": {
                                             "registrationOffice": "Temp Registergericht Aurich",
                                             "registrationNumber": "111111"
@@ -155,8 +150,6 @@ class HsOfficePartnerControllerRestTest {
                                     """.formatted(
                                     GIVEN_MANDANTE_UUID,
                                     GIVEN_PERSON_UUID,
-                                    GIVEN_INVALID_UUID,
-                                    GIVEN_PERSON_UUID,
                                     GIVEN_INVALID_UUID))
                             .accept(MediaType.APPLICATION_JSON))
 
diff --git a/src/test/java/net/hostsharing/hsadminng/hs/office/partner/HsOfficePartnerEntityPatcherUnitTest.java b/src/test/java/net/hostsharing/hsadminng/hs/office/partner/HsOfficePartnerEntityPatcherUnitTest.java
index b38c41ae..e7f09b03 100644
--- a/src/test/java/net/hostsharing/hsadminng/hs/office/partner/HsOfficePartnerEntityPatcherUnitTest.java
+++ b/src/test/java/net/hostsharing/hsadminng/hs/office/partner/HsOfficePartnerEntityPatcherUnitTest.java
@@ -1,20 +1,25 @@
 package net.hostsharing.hsadminng.hs.office.partner;
 
 import net.hostsharing.hsadminng.hs.office.contact.HsOfficeContactRealEntity;
+import net.hostsharing.hsadminng.hs.office.generated.api.v1.model.HsOfficePartnerDetailsPatchResource;
 import net.hostsharing.hsadminng.hs.office.generated.api.v1.model.HsOfficePartnerPatchResource;
+import net.hostsharing.hsadminng.hs.office.generated.api.v1.model.HsOfficeRelationPatchResource;
 import net.hostsharing.hsadminng.hs.office.person.HsOfficePersonRealEntity;
 import net.hostsharing.hsadminng.hs.office.relation.HsOfficeRelationRealEntity;
-import net.hostsharing.hsadminng.rbac.test.PatchUnitTestBase;
+import net.hostsharing.hsadminng.mapper.StrictMapper;
+import net.hostsharing.hsadminng.persistence.EntityManagerWrapper;
 import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.TestInstance;
 import org.junit.jupiter.api.extension.ExtendWith;
 import org.mockito.Mock;
 import org.mockito.junit.jupiter.MockitoExtension;
+import org.openapitools.jackson.nullable.JsonNullable;
 
-import jakarta.persistence.EntityManager;
+import java.time.LocalDate;
 import java.util.UUID;
-import java.util.stream.Stream;
 
+import static org.assertj.core.api.Assertions.assertThat;
 import static org.junit.jupiter.api.TestInstance.Lifecycle.PER_CLASS;
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.ArgumentMatchers.eq;
@@ -22,19 +27,17 @@ import static org.mockito.Mockito.lenient;
 
 @TestInstance(PER_CLASS)
 @ExtendWith(MockitoExtension.class)
-class HsOfficePartnerEntityPatcherUnitTest extends PatchUnitTestBase<
-        HsOfficePartnerPatchResource,
-        HsOfficePartnerRbacEntity
-        > {
+// This test class does not subclass PatchUnitTestBase because it has no directly patchable properties.
+// But the factory-structure is kept, so PatchUnitTestBase could easily be plugged back in if needed.
+class HsOfficePartnerEntityPatcherUnitTest {
 
     private static final UUID INITIAL_PARTNER_UUID = UUID.randomUUID();
     private static final UUID INITIAL_CONTACT_UUID = UUID.randomUUID();
-    private static final UUID INITIAL_PERSON_UUID = UUID.randomUUID();
+    private static final UUID INITIAL_PARTNER_PERSON_UUID = UUID.randomUUID();
     private static final UUID INITIAL_DETAILS_UUID = UUID.randomUUID();
-    private static final UUID PATCHED_PARTNER_ROLE_UUID = UUID.randomUUID();
 
-    private final HsOfficePersonRealEntity givenInitialPerson = HsOfficePersonRealEntity.builder()
-            .uuid(INITIAL_PERSON_UUID)
+    private final HsOfficePersonRealEntity givenInitialPartnerPerson = HsOfficePersonRealEntity.builder()
+            .uuid(INITIAL_PARTNER_PERSON_UUID)
             .build();
     private final HsOfficeContactRealEntity givenInitialContact = HsOfficeContactRealEntity.builder()
             .uuid(INITIAL_CONTACT_UUID)
@@ -43,22 +46,74 @@ class HsOfficePartnerEntityPatcherUnitTest extends PatchUnitTestBase<
     private final HsOfficePartnerDetailsEntity givenInitialDetails = HsOfficePartnerDetailsEntity.builder()
             .uuid(INITIAL_DETAILS_UUID)
             .build();
+
     @Mock
-    private EntityManager em;
+    private EntityManagerWrapper emw;
+
+    private StrictMapper mapper = new StrictMapper(emw);
 
     @BeforeEach
     void initMocks() {
-        lenient().when(em.getReference(eq(HsOfficeRelationRealEntity.class), any())).thenAnswer(invocation ->
-                HsOfficeRelationRealEntity.builder().uuid(invocation.getArgument(1)).build());
+        lenient().when(emw.getReference(eq(HsOfficePersonRealEntity.class), any())).thenAnswer(invocation ->
+                HsOfficePersonRealEntity.builder().uuid(invocation.getArgument(1)).build());
+        lenient().when(emw.getReference(eq(HsOfficeContactRealEntity.class), any())).thenAnswer(invocation ->
+                HsOfficeContactRealEntity.builder().uuid(invocation.getArgument(1)).build());
+    }
+
+    @Test
+    void patchPartnerPerson() {
+        // given
+        final var patchResource = newPatchResource();
+        final var newHolderUuid = UUID.randomUUID();
+        patchResource.setPartnerRel(new HsOfficeRelationPatchResource());
+        patchResource.getPartnerRel().setHolderUuid(JsonNullable.of(newHolderUuid));
+        final var entity = newInitialEntity();
+
+        // when
+        createPatcher(entity).apply(patchResource);
+
+        // then
+        assertThat(entity.getPartnerRel().getHolder().getUuid()).isEqualTo(newHolderUuid);
+    }
+
+    @Test
+    void patchPartnerContact() {
+        // given
+        final var patchResource = newPatchResource();
+        final var newContactUuid = UUID.randomUUID();
+        patchResource.setPartnerRel(new HsOfficeRelationPatchResource());
+        patchResource.getPartnerRel().setContactUuid(JsonNullable.of(newContactUuid));
+        final var entity = newInitialEntity();
+
+        // when
+        createPatcher(entity).apply(patchResource);
+
+        // then
+        assertThat(entity.getPartnerRel().getContact().getUuid()).isEqualTo(newContactUuid);
+    }
+
+    @Test
+    void patchPartnerDetails() {
+        // given
+        final var patchResource = newPatchResource();
+        final var newDateOfBirth = LocalDate.now();
+        patchResource.setDetails(new HsOfficePartnerDetailsPatchResource());
+        patchResource.getDetails().setDateOfDeath(JsonNullable.of(newDateOfBirth));
+        final var entity = newInitialEntity();
+
+        // when
+        createPatcher(entity).apply(patchResource);
+
+        // then
+        assertThat(entity.getDetails().getDateOfDeath()).isEqualTo(newDateOfBirth);
     }
 
-    @Override
     protected HsOfficePartnerRbacEntity newInitialEntity() {
         final var entity = HsOfficePartnerRbacEntity.builder()
                 .uuid(INITIAL_PARTNER_UUID)
                 .partnerNumber(12345)
                 .partnerRel(HsOfficeRelationRealEntity.builder()
-                        .holder(givenInitialPerson)
+                        .holder(givenInitialPartnerPerson)
                         .contact(givenInitialContact)
                         .build())
                 .details(givenInitialDetails)
@@ -66,32 +121,11 @@ class HsOfficePartnerEntityPatcherUnitTest extends PatchUnitTestBase<
         return entity;
     }
 
-    @Override
     protected HsOfficePartnerPatchResource newPatchResource() {
         return new HsOfficePartnerPatchResource();
     }
 
-    @Override
     protected HsOfficePartnerEntityPatcher createPatcher(final HsOfficePartnerRbacEntity partner) {
-        return new HsOfficePartnerEntityPatcher(em, partner);
-    }
-
-    @Override
-    protected Stream<Property> propertyTestDescriptors() {
-        return Stream.of(
-                new JsonNullableProperty<>(
-                        "partnerRel",
-                        HsOfficePartnerPatchResource::setPartnerRelUuid,
-                        PATCHED_PARTNER_ROLE_UUID,
-                        HsOfficePartnerRbacEntity::setPartnerRel,
-                        newPartnerRel(PATCHED_PARTNER_ROLE_UUID))
-                        .notNullable()
-        );
-    }
-
-    private static HsOfficeRelationRealEntity newPartnerRel(final UUID uuid) {
-        return HsOfficeRelationRealEntity.builder()
-                    .uuid(uuid)
-                    .build();
+        return new HsOfficePartnerEntityPatcher(mapper, emw, partner);
     }
 }
diff --git a/src/test/java/net/hostsharing/hsadminng/hs/office/relation/HsOfficeRelationPatcherUnitTest.java b/src/test/java/net/hostsharing/hsadminng/hs/office/relation/HsOfficeRelationPatcherUnitTest.java
index 343fcd90..8647fc19 100644
--- a/src/test/java/net/hostsharing/hsadminng/hs/office/relation/HsOfficeRelationPatcherUnitTest.java
+++ b/src/test/java/net/hostsharing/hsadminng/hs/office/relation/HsOfficeRelationPatcherUnitTest.java
@@ -1,23 +1,38 @@
 package net.hostsharing.hsadminng.hs.office.relation;
 
+import net.hostsharing.hsadminng.hs.office.contact.HsOfficeContactFromResourceConverter;
 import net.hostsharing.hsadminng.hs.office.contact.HsOfficeContactRealEntity;
+import net.hostsharing.hsadminng.hs.office.generated.api.v1.model.HsOfficeContactInsertResource;
+import net.hostsharing.hsadminng.hs.office.generated.api.v1.model.HsOfficePersonInsertResource;
+import net.hostsharing.hsadminng.hs.office.generated.api.v1.model.HsOfficePersonTypeResource;
 import net.hostsharing.hsadminng.hs.office.generated.api.v1.model.HsOfficeRelationPatchResource;
 import net.hostsharing.hsadminng.hs.office.person.HsOfficePersonRealEntity;
+import net.hostsharing.hsadminng.mapper.StrictMapper;
+import net.hostsharing.hsadminng.persistence.EntityManagerWrapper;
 import net.hostsharing.hsadminng.rbac.test.PatchUnitTestBase;
 import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.TestInstance;
 import org.junit.jupiter.api.extension.ExtendWith;
 import org.mockito.Mock;
 import org.mockito.junit.jupiter.MockitoExtension;
+import org.openapitools.jackson.nullable.JsonNullable;
 
-import jakarta.persistence.EntityManager;
+import jakarta.validation.ValidationException;
+import java.util.Map;
 import java.util.UUID;
 import java.util.stream.Stream;
 
+import static net.hostsharing.hsadminng.hs.office.person.HsOfficePersonType.LEGAL_PERSON;
+import static net.hostsharing.hsadminng.hs.office.person.HsOfficePersonType.NATURAL_PERSON;
+import static net.hostsharing.hsadminng.hs.office.relation.HsOfficeRelationType.PARTNER;
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.catchThrowable;
+import static org.assertj.core.api.Assumptions.assumeThat;
 import static org.junit.jupiter.api.TestInstance.Lifecycle.PER_CLASS;
-import static org.mockito.ArgumentMatchers.any;
-import static org.mockito.ArgumentMatchers.eq;
 import static org.mockito.Mockito.lenient;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
 
 @TestInstance(PER_CLASS)
 @ExtendWith(MockitoExtension.class)
@@ -26,36 +41,84 @@ class HsOfficeRelationPatcherUnitTest extends PatchUnitTestBase<
         HsOfficeRelation
         > {
 
-    static final UUID INITIAL_RELATION_UUID = UUID.randomUUID();
-    static final UUID PATCHED_CONTACT_UUID = UUID.randomUUID();
+    private static final UUID INITIAL_RELATION_UUID = UUID.randomUUID();
+    private static final UUID INITIAL_ANCHOR_UUID = UUID.randomUUID();
+    private static final UUID INITIAL_HOLDER_UUID = UUID.randomUUID();
+    private static final UUID INITIAL_CONTACT_UUID = UUID.randomUUID();
+
+    private static final UUID PATCHED_HOLDER_UUID = UUID.randomUUID();
+    private static HsOfficePersonInsertResource HOLDER_PATCH_RESOURCE = new HsOfficePersonInsertResource();
+    {
+        {
+            HOLDER_PATCH_RESOURCE.setPersonType(HsOfficePersonTypeResource.NATURAL_PERSON);
+            HOLDER_PATCH_RESOURCE.setFamilyName("Patched-Holder-Family-Name");
+            HOLDER_PATCH_RESOURCE.setGivenName("Patched-Holder-Given-Name");
+        }
+    };
+    private static HsOfficePersonRealEntity PATCHED_HOLDER = HsOfficePersonRealEntity.builder()
+            .uuid(PATCHED_HOLDER_UUID)
+            .personType(NATURAL_PERSON)
+            .familyName("Patched-Holder-Family-Name")
+            .givenName("Patched-Holder-Given-Name")
+            .build();
+
+    private static final UUID PATCHED_CONTACT_UUID = UUID.randomUUID();
+    private static HsOfficeContactInsertResource CONTACT_PATCH_RESOURCE = new HsOfficeContactInsertResource();
+    {
+        {
+            CONTACT_PATCH_RESOURCE.setCaption("Patched-Contact-Caption");
+            CONTACT_PATCH_RESOURCE.setEmailAddresses(Map.ofEntries(
+                    Map.entry("main", "patched@example.org")
+            ));
+        }
+    };
+    private static HsOfficeContactRealEntity PATCHED_CONTACT = HsOfficeContactRealEntity.builder()
+            .uuid(PATCHED_CONTACT_UUID)
+            .caption("Patched-Contact-Caption")
+            .emailAddresses(Map.ofEntries(
+                    Map.entry("main", "patched@example.org")
+            ))
+            .build();
 
     @Mock
-    EntityManager em;
+    private EntityManagerWrapper emw;
+
+    private StrictMapper mapper;
+
 
     @BeforeEach
-    void initMocks() {
-        lenient().when(em.getReference(eq(HsOfficeContactRealEntity.class), any())).thenAnswer(invocation ->
-                HsOfficeContactRealEntity.builder().uuid(invocation.getArgument(1)).build());
-    }
+    void init() {
+        mapper = new StrictMapper(emw); // emw is injected after the constructor got called
+        mapper.addConverter(
+                    new HsOfficeContactFromResourceConverter<>(),
+                    HsOfficeContactInsertResource.class, HsOfficeContactRealEntity.class);
 
-    final HsOfficePersonRealEntity givenInitialAnchorPerson = HsOfficePersonRealEntity.builder()
-            .uuid(UUID.randomUUID())
-            .build();
-    final HsOfficePersonRealEntity givenInitialHolderPerson = HsOfficePersonRealEntity.builder()
-            .uuid(UUID.randomUUID())
-            .build();
-    final HsOfficeContactRealEntity givenInitialContact = HsOfficeContactRealEntity.builder()
-            .uuid(UUID.randomUUID())
-            .build();
+        lenient().when(emw.getReference(HsOfficePersonRealEntity.class, PATCHED_HOLDER_UUID)).thenAnswer(
+                p -> PATCHED_HOLDER);
+        lenient().when(emw.getReference(HsOfficeContactRealEntity.class, PATCHED_CONTACT_UUID)).thenAnswer(
+                p -> PATCHED_CONTACT);
+    }
 
     @Override
     protected HsOfficeRelation newInitialEntity() {
-        final var entity = new HsOfficeRelationRbacEntity();
+        final var entity = new HsOfficeRelationRealEntity();
         entity.setUuid(INITIAL_RELATION_UUID);
-        entity.setType(HsOfficeRelationType.REPRESENTATIVE);
-        entity.setAnchor(givenInitialAnchorPerson);
-        entity.setHolder(givenInitialHolderPerson);
-        entity.setContact(givenInitialContact);
+        entity.setType(PARTNER);
+        entity.setAnchor(HsOfficePersonRealEntity.builder()
+                .uuid(INITIAL_ANCHOR_UUID)
+                .personType(LEGAL_PERSON)
+                .tradeName("Initial-Anchor-Tradename")
+                .build());
+        entity.setHolder(HsOfficePersonRealEntity.builder()
+                .uuid(INITIAL_HOLDER_UUID)
+                .personType(NATURAL_PERSON)
+                .familyName("Initial-Holder-Family-Name")
+                .givenName("Initial-Holder-Given-Name")
+                .build());
+        entity.setContact(HsOfficeContactRealEntity.builder()
+                .uuid(INITIAL_CONTACT_UUID)
+                .caption("Initial-Contact-Caption")
+                .build());
         return entity;
     }
 
@@ -65,24 +128,114 @@ class HsOfficeRelationPatcherUnitTest extends PatchUnitTestBase<
     }
 
     @Override
-    protected HsOfficeRelationEntityPatcher createPatcher(final HsOfficeRelation relation) {
-        return new HsOfficeRelationEntityPatcher(em, relation);
+    protected HsOfficeRelationPatcher createPatcher(final HsOfficeRelation relation) {
+        return new HsOfficeRelationPatcher(mapper, emw, relation);
     }
 
     @Override
     protected Stream<Property> propertyTestDescriptors() {
         return Stream.of(
                 new JsonNullableProperty<>(
-                        "contact",
+                        "holderUuid",
+                        HsOfficeRelationPatchResource::setHolderUuid,
+                        PATCHED_HOLDER_UUID,
+                        HsOfficeRelation::setHolder,
+                        PATCHED_HOLDER),
+                new SimpleProperty<>(
+                        "holder",
+                        HsOfficeRelationPatchResource::setHolder,
+                        HOLDER_PATCH_RESOURCE,
+                        HsOfficeRelation::setHolder,
+                        withoutUuid(PATCHED_HOLDER))
+                        .notNullable(),
+
+                new JsonNullableProperty<>(
+                        "contactUuid",
                         HsOfficeRelationPatchResource::setContactUuid,
                         PATCHED_CONTACT_UUID,
                         HsOfficeRelation::setContact,
-                        newContact(PATCHED_CONTACT_UUID))
+                        PATCHED_CONTACT),
+                new SimpleProperty<>(
+                        "contact",
+                        HsOfficeRelationPatchResource::setContact,
+                        CONTACT_PATCH_RESOURCE,
+                        HsOfficeRelation::setContact,
+                        withoutUuid(PATCHED_CONTACT))
                         .notNullable()
         );
     }
 
-    static HsOfficeContactRealEntity newContact(final UUID uuid) {
-        return HsOfficeContactRealEntity.builder().uuid(uuid).build();
+    @Override
+    protected void willPatchAllProperties() {
+        // this generic test does not work because either holder or holder.uuid can be set
+        assumeThat(true).isFalse();
+    }
+
+    @Test
+    void willThrowExceptionIfHolderAndHolderUuidAreGiven() {
+        // given
+        final var givenEntity = newInitialEntity();
+        final var patchResource = newPatchResource();
+        patchResource.setHolderUuid(JsonNullable.of(PATCHED_HOLDER_UUID));
+        patchResource.setHolder(HOLDER_PATCH_RESOURCE);
+
+        // when
+        final var exception = catchThrowable(() -> createPatcher(givenEntity).apply(patchResource));
+
+        // then
+        assertThat(exception).isInstanceOf(ValidationException.class)
+                .hasMessage("either \"holder\" or \"holder.uuid\" can be given, not both");
+    }
+
+    @Test
+    void willThrowExceptionIfContactAndContactUuidAreGiven() {
+        // given
+        final var givenEntity = newInitialEntity();
+        final var patchResource = newPatchResource();
+        patchResource.setContactUuid(JsonNullable.of(PATCHED_CONTACT_UUID));
+        patchResource.setContact(CONTACT_PATCH_RESOURCE);
+
+        // when
+        final var exception =  catchThrowable(() -> createPatcher(givenEntity).apply(patchResource));
+
+        // then
+        assertThat(exception).isInstanceOf(ValidationException.class)
+                .hasMessage("either \"contact\" or \"contact.uuid\" can be given, not both");
+    }
+
+    @Test
+    void willPersistNewHolder() {
+        // given
+        final var givenEntity = newInitialEntity();
+        final var patchResource = newPatchResource();
+        patchResource.setHolder(HOLDER_PATCH_RESOURCE);
+
+        // when
+        createPatcher(givenEntity).apply(patchResource);
+
+        // then
+        verify(emw, times(1)).persist(givenEntity.getHolder());
+    }
+
+    @Test
+    void willPersistNewContact() {
+        // given
+        final var givenEntity = newInitialEntity();
+        final var patchResource = newPatchResource();
+        patchResource.setContact(CONTACT_PATCH_RESOURCE);
+
+        // when
+        createPatcher(givenEntity).apply(patchResource);
+
+        // then
+        verify(emw, times(1)).persist(givenEntity.getContact());
+    }
+
+    private HsOfficePersonRealEntity withoutUuid(final HsOfficePersonRealEntity givenWithUuid) {
+        return givenWithUuid.toBuilder().uuid(null).build();
+    }
+
+    private HsOfficeContactRealEntity withoutUuid(final HsOfficeContactRealEntity givenWithUuid) {
+        return givenWithUuid.toBuilder().uuid(null).build();
     }
 }
diff --git a/src/test/java/net/hostsharing/hsadminng/hs/office/relation/HsOfficeRelationRepositoryIntegrationTest.java b/src/test/java/net/hostsharing/hsadminng/hs/office/relation/HsOfficeRelationRepositoryIntegrationTest.java
index 5e8c750b..d316274d 100644
--- a/src/test/java/net/hostsharing/hsadminng/hs/office/relation/HsOfficeRelationRepositoryIntegrationTest.java
+++ b/src/test/java/net/hostsharing/hsadminng/hs/office/relation/HsOfficeRelationRepositoryIntegrationTest.java
@@ -28,6 +28,7 @@ import static net.hostsharing.hsadminng.hs.office.person.HsOfficePersonType.NATU
 import static net.hostsharing.hsadminng.hs.office.person.HsOfficePersonType.UNINCORPORATED_FIRM;
 import static net.hostsharing.hsadminng.rbac.grant.RawRbacGrantEntity.distinctGrantDisplaysOf;
 import static net.hostsharing.hsadminng.rbac.role.RawRbacRoleEntity.distinctRoleNamesOf;
+import static net.hostsharing.hsadminng.rbac.role.RbacRoleType.ADMIN;
 import static net.hostsharing.hsadminng.rbac.test.JpaAttempt.attempt;
 import static org.assertj.core.api.Assertions.assertThat;
 
@@ -282,7 +283,40 @@ class HsOfficeRelationRepositoryIntegrationTest extends ContextBasedTestWithClea
             assertThatRelationIsNotVisibleForUserWithRole(
                     result.returnedValue(),
                     "hs_office.contact#fifthcontact:ADMIN");
+        }
 
+        @Test
+        public void hostsharingAdmin_withoutAssumedRole_canUpdateHolderOfArbitraryRelation() {
+            // given
+            context("superuser-alex@hostsharing.net");
+            final var givenRelation = givenSomeTemporaryRelationBessler(
+                    "Bert", "fifth contact");
+            final var oldHolderPerson = givenRelation.getHolder();
+            final var newHolderPerson = personRepo.findPersonByOptionalNameLike("Paul").getFirst();
+            assertThatRelationActuallyInDatabase(givenRelation);
+            assertThatRelationIsVisibleForUserWithRole(
+                    givenRelation,
+                    givenRelation.getHolder().roleId(ADMIN));
+
+            // when
+            final var result = jpaAttempt.transacted(() -> {
+                context("superuser-alex@hostsharing.net");
+                givenRelation.setHolder(newHolderPerson);
+                return toCleanup(relationRbacRepo.save(givenRelation).load());
+            });
+
+            // then
+            result.assertSuccessful();
+            assertThat(result.returnedValue().getHolder().getGivenName()).isEqualTo("Paul");
+            assertThatRelationIsVisibleForUserWithRole(
+                    result.returnedValue(),
+                    "rbac.global#global:ADMIN");
+            assertThatRelationIsVisibleForUserWithRole(
+                    result.returnedValue(),
+                    newHolderPerson.roleId(ADMIN));
+            assertThatRelationIsNotVisibleForUserWithRole(
+                    result.returnedValue(),
+                    oldHolderPerson.roleId(ADMIN));
         }
 
         @Test
diff --git a/src/test/java/net/hostsharing/hsadminng/hs/office/scenarios/HsOfficeScenarioTests.java b/src/test/java/net/hostsharing/hsadminng/hs/office/scenarios/HsOfficeScenarioTests.java
index 646896e9..e643ea8a 100644
--- a/src/test/java/net/hostsharing/hsadminng/hs/office/scenarios/HsOfficeScenarioTests.java
+++ b/src/test/java/net/hostsharing/hsadminng/hs/office/scenarios/HsOfficeScenarioTests.java
@@ -7,6 +7,7 @@ import net.hostsharing.hsadminng.hs.office.scenarios.contact.RemovePhoneNumberFr
 import net.hostsharing.hsadminng.hs.office.scenarios.contact.ReplaceContactData;
 import net.hostsharing.hsadminng.hs.office.scenarios.debitor.CreateExternalDebitorForPartner;
 import net.hostsharing.hsadminng.hs.office.scenarios.debitor.CreateSelfDebitorForPartner;
+import net.hostsharing.hsadminng.hs.office.scenarios.debitor.CreateSelfDebitorForPartnerWithIdenticalContactData;
 import net.hostsharing.hsadminng.hs.office.scenarios.debitor.CreateSepaMandateForDebitor;
 import net.hostsharing.hsadminng.hs.office.scenarios.debitor.DeleteDebitor;
 import net.hostsharing.hsadminng.hs.office.scenarios.debitor.DontDeleteDefaultDebitor;
@@ -265,11 +266,27 @@ class HsOfficeScenarioTests extends ScenarioTest {
     @TestMethodOrder(MethodOrderer.OrderAnnotation.class)
     class DebitorScenarios {
 
+        @Test
+        @Order(2000)
+        @Requires("Partner: P-31011 - Michelle Matthieu")
+        @Produces("Debitor: D-3101100 - Michelle Matthieu")
+        void shouldCreateSelfDebitorForPartnerWithIdenticalContactData() {
+            new CreateSelfDebitorForPartnerWithIdenticalContactData(scenarioTest)
+                    .given("partnerNumber", "P-31011")
+                    .given("debitorNumberSuffix", "00") // TODO.impl: could be assigned automatically, but is not yet
+                    .given("billable", true)
+                    .given("vatBusiness", false)
+                    .given("vatReverseCharge", false)
+                    .given("defaultPrefix", "mim")
+                    .doRun()
+                    .keep();
+        }
+
         @Test
         @Order(2010)
         @Requires("Partner: P-31010 - Test AG")
         @Produces("Debitor: D-3101000 - Test AG - main debitor")
-        void shouldCreateSelfDebitorForPartner() {
+        void shouldCreateSelfDebitorForPartnerWithDistinctContactData() {
             new CreateSelfDebitorForPartner(scenarioTest)
                     .given("partnerPersonTradeName", "Test AG")
                     .given("billingContactCaption", "Test AG - billing department")
@@ -654,7 +671,7 @@ class HsOfficeScenarioTests extends ScenarioTest {
 
         @Test
         @Order(6010)
-        @Requires("Partner: P-31011 - Michelle Matthieu")
+        @Requires("Debitor: D-3101100 - Michelle Matthieu") // which should also get updated
         void shouldReplaceDeceasedPartnerByCommunityOfHeirs() {
             new ReplaceDeceasedPartnerWithCommunityOfHeirs(scenarioTest)
                     .given("partnerNumber", "P-31011")
diff --git a/src/test/java/net/hostsharing/hsadminng/hs/office/scenarios/debitor/CreateSelfDebitorForPartnerWithIdenticalContactData.java b/src/test/java/net/hostsharing/hsadminng/hs/office/scenarios/debitor/CreateSelfDebitorForPartnerWithIdenticalContactData.java
new file mode 100644
index 00000000..1cb08ce4
--- /dev/null
+++ b/src/test/java/net/hostsharing/hsadminng/hs/office/scenarios/debitor/CreateSelfDebitorForPartnerWithIdenticalContactData.java
@@ -0,0 +1,45 @@
+package net.hostsharing.hsadminng.hs.office.scenarios.debitor;
+
+import net.hostsharing.hsadminng.hs.scenarios.ScenarioTest;
+import net.hostsharing.hsadminng.hs.scenarios.UseCase;
+import org.springframework.http.HttpStatus;
+
+import static io.restassured.http.ContentType.JSON;
+import static org.springframework.http.HttpStatus.CREATED;
+
+public class CreateSelfDebitorForPartnerWithIdenticalContactData
+        extends UseCase<CreateSelfDebitorForPartnerWithIdenticalContactData> {
+
+    public CreateSelfDebitorForPartnerWithIdenticalContactData(final ScenarioTest testSuite) {
+        super(testSuite);
+    }
+
+    @Override
+    protected HttpResponse run() {
+        withTitle("Determine Partner-Person UUID", () ->
+                httpGet("/api/hs/office/partners/" + uriEncoded("%{partnerNumber}"))
+                        .reportWithResponse().expecting(HttpStatus.OK).expecting(JSON)
+                        .extractUuidAlias("partnerRel.holder.uuid", "partnerPersonUuid")
+                        .extractUuidAlias("partnerRel.contact.uuid", "partnerContactUuid")
+        );
+
+        return httpPost("/api/hs/office/debitors", usingJsonBody("""
+                {
+                    "debitorRel": {
+                        "anchor.uuid": ${partnerPersonUuid},
+                        "holder.uuid": ${partnerPersonUuid},
+                        "contact.uuid": ${partnerContactUuid}
+                     },
+                    "debitorNumberSuffix": ${debitorNumberSuffix},
+                    "billable": ${billable},
+                    "vatId": ${vatId???},
+                    "vatCountryCode": ${vatCountryCode???},
+                    "vatBusiness": ${vatBusiness},
+                    "vatReverseCharge": ${vatReverseCharge},
+                    "defaultPrefix": ${defaultPrefix}
+                }
+                """))
+                .expecting(CREATED).expecting(JSON);
+    }
+
+}
diff --git a/src/test/java/net/hostsharing/hsadminng/hs/office/scenarios/partner/ReplaceDeceasedPartnerWithCommunityOfHeirs.java b/src/test/java/net/hostsharing/hsadminng/hs/office/scenarios/partner/ReplaceDeceasedPartnerWithCommunityOfHeirs.java
index c706e8e6..1db638df 100644
--- a/src/test/java/net/hostsharing/hsadminng/hs/office/scenarios/partner/ReplaceDeceasedPartnerWithCommunityOfHeirs.java
+++ b/src/test/java/net/hostsharing/hsadminng/hs/office/scenarios/partner/ReplaceDeceasedPartnerWithCommunityOfHeirs.java
@@ -12,101 +12,81 @@ public class ReplaceDeceasedPartnerWithCommunityOfHeirs extends UseCase<ReplaceD
 
     public ReplaceDeceasedPartnerWithCommunityOfHeirs(final ScenarioTest testSuite) {
         super(testSuite);
-
     }
 
     @Override
     protected HttpResponse run() {
 
-        obtain("Person: Hostsharing eG", () ->
-            httpGet("/api/hs/office/persons?name=Hostsharing+eG")
-                    .expecting(OK).expecting(JSON),
-                    response -> response.expectArrayElements(1).getFromBody("[0].uuid"),
-                "Even in production data we expect this query to return just a single result." // TODO.impl: add constraint?
-        );
-
-        obtain("Partner: %{partnerNumber}", () ->
-                httpGet("/api/hs/office/partners/%{partnerNumber}")
-                .reportWithResponse().expecting(OK).expecting(JSON),
+        obtain("Partner: %{partnerNumber}",
+                () -> httpGet("/api/hs/office/partners/%{partnerNumber}")
+                                .reportWithResponse().expecting(OK).expecting(JSON),
                 response -> response.getFromBody("uuid"),
-                "Even in production data we expect this query to return just a single result." // TODO.impl: add constraint?
+                "Even in production data we expect this query to return just a single result."
+                // TODO.impl: add constraint?
         )
                 .extractValue("partnerRel.holder.familyName", "familyNameOfDeceasedPerson")
                 .extractValue("partnerRel.holder.givenName", "givenNameOfDeceasedPerson")
-                .extractUuidAlias("partnerRel.holder.uuid", "Person: %{givenNameOfDeceasedPerson} %{familyNameOfDeceasedPerson}");
+                .extractUuidAlias(
+                        "partnerRel.holder.uuid",
+                        "Person: %{givenNameOfDeceasedPerson} %{familyNameOfDeceasedPerson}");
 
-        obtain("Partner-Relation: Erbengemeinschaft %{givenNameOfDeceasedPerson} %{familyNameOfDeceasedPerson}", () ->
-            httpPost("/api/hs/office/relations", usingJsonBody("""
-                {
-                   "type": "PARTNER",
-                   "anchor.uuid": ${Person: Hostsharing eG},
-                   "holder": {
-                        "personType": "UNINCORPORATED_FIRM",
-                        "tradeName": "Erbengemeinschaft %{givenNameOfDeceasedPerson} %{familyNameOfDeceasedPerson}",
-                    },
-                   "contact": {
-                        "caption": "Erbengemeinschaft %{givenNameOfDeceasedPerson} %{familyNameOfDeceasedPerson}",
-                        "postalAddress": {
-                            "name": "Erbengemeinschaft %{givenNameOfDeceasedPerson} %{familyNameOfDeceasedPerson}",
-                            "co": "%{representativeGivenName} %{representativeFamilyName}",
-                            %{communityOfHeirsPostalAddress}
-                        },
-                        "phoneNumbers": {
-                            "office": ${communityOfHeirsOfficePhoneNumber}
-                        },
-                        "emailAddresses": {
-                            "main": ${communityOfHeirsEmailAddress}
-                        }
-                    }
-                }
-                """))
-                .reportWithResponse().expecting(CREATED).expecting(JSON)
-        )
-                .extractUuidAlias("contact.uuid", "Contact: Erbengemeinschaft %{givenNameOfDeceasedPerson} %{familyNameOfDeceasedPerson}")
-                .extractUuidAlias("holder.uuid", "Person: Erbengemeinschaft %{givenNameOfDeceasedPerson} %{familyNameOfDeceasedPerson}");
-
-        obtain("Representative-Relation: %{representativeGivenName} %{representativeFamilyName} for Erbengemeinschaft %{givenNameOfDeceasedPerson} %{familyNameOfDeceasedPerson}", () ->
-                httpPost("/api/hs/office/relations", usingJsonBody("""
-                {
-                   "type": "REPRESENTATIVE",
-                   "anchor.uuid": ${Person: Erbengemeinschaft %{givenNameOfDeceasedPerson} %{familyNameOfDeceasedPerson}},
-                   "holder": {
-                        "personType": "NATURAL_PERSON",
-                        "givenName": ${representativeGivenName},
-                        "familyName": ${representativeFamilyName}
-                    },
-                   "contact.uuid": ${Contact: Erbengemeinschaft %{givenNameOfDeceasedPerson} %{familyNameOfDeceasedPerson}}
-                }
-                """))
-                .reportWithResponse().expecting(CREATED).expecting(JSON)
-        ).extractUuidAlias("holder.uuid", "Person: %{representativeGivenName} %{representativeFamilyName}");
-
-        obtain("Partner: Erbengemeinschaft %{givenNameOfDeceasedPerson} %{familyNameOfDeceasedPerson}", () ->
-            httpPatch("/api/hs/office/partners/%{Partner: %{partnerNumber}}", usingJsonBody("""
-                        {
-                            "partnerRel.uuid": ${Partner-Relation: Erbengemeinschaft %{givenNameOfDeceasedPerson} %{familyNameOfDeceasedPerson}}
-                        }
-                        """))
-                    .expecting(HttpStatus.OK)
+        withTitle("New Partner-Person+Contact: Erbengemeinschaft %{givenNameOfDeceasedPerson} %{familyNameOfDeceasedPerson}",
+                () -> httpPatch("/api/hs/office/partners/%{Partner: %{partnerNumber}}",
+                        usingJsonBody("""
+                                {
+                                    "wrong1": false,
+                                    "partnerRel": {
+                                        "wrong2": false,
+                                        "holder": {
+                                            "personType": "UNINCORPORATED_FIRM",
+                                            "tradeName": "Erbengemeinschaft %{givenNameOfDeceasedPerson} %{familyNameOfDeceasedPerson}",
+                                        },
+                                        "contact": {
+                                            "wrong3": false,
+                                            "caption": "Erbengemeinschaft %{givenNameOfDeceasedPerson} %{familyNameOfDeceasedPerson}",
+                                            "postalAddress": {
+                                                "wrong4": false,
+                                                "name": "Erbengemeinschaft %{givenNameOfDeceasedPerson} %{familyNameOfDeceasedPerson}",
+                                                "co": "%{representativeGivenName} %{representativeFamilyName}",
+                                                %{communityOfHeirsPostalAddress}
+                                            },
+                                            "phoneNumbers": {
+                                                "office": ${communityOfHeirsOfficePhoneNumber}
+                                            },
+                                            "emailAddresses": {
+                                                "main": ${communityOfHeirsEmailAddress}
+                                            }
+                                        }
+                                    }
+                                }
+                                """))
+                        .reportWithResponse().expecting(HttpStatus.OK).expecting(JSON)
+                        .extractUuidAlias(
+                                "partnerRel.holder.uuid",
+                                "Person: Erbengemeinschaft %{givenNameOfDeceasedPerson} %{familyNameOfDeceasedPerson}")
+                        .extractUuidAlias(
+                                "partnerRel.contact.uuid",
+                                "Contact: Erbengemeinschaft %{givenNameOfDeceasedPerson} %{familyNameOfDeceasedPerson}")
         );
 
-        // TODO.test: missing steps Debitor, Membership, Coop-Shares+Assets
-
-        // Debitors
-
-        // die Erbengemeinschaft wird als Anchor-Person (Partner) in die Debitor-Relations eingetragen
-        // der neue Rechnungsempfänger (z.B. auch ggf. Rechtsanwalt) wird als Holder-Person (Debitor-Person) in die Debitor-Relations eingetragen -- oder neu?
-
-        // Membership
-
-        // intro: die Mitgliedschaft geht juristisch gesehen auf die Erbengemeinschaft über
-
-        // die bisherige Mitgliedschaft als DECEASED mit Ende-Datum=Todesdatum markieren
-
-        // eine neue Mitgliedschaft (-00) mit dem Start-Datum=Todesdatum+1 anlegen
-
-        // die Geschäftsanteile per share-tx: TRANSFER→ADOPT an die Erbengemeinschaft übertragen
-        // die Geschäftsguthaben per asset-tx: TRANSFER→ADOPT an die Erbengemeinschaft übertragen
+        obtain(
+                "Representative-Relation: %{representativeGivenName} %{representativeFamilyName} for Erbengemeinschaft %{givenNameOfDeceasedPerson} %{familyNameOfDeceasedPerson}",
+                () -> httpPost("/api/hs/office/relations",
+                        usingJsonBody("""
+                                {
+                                   "type": "REPRESENTATIVE",
+                                   "anchor.uuid": ${Person: Erbengemeinschaft %{givenNameOfDeceasedPerson} %{familyNameOfDeceasedPerson}},
+                                   "holder": {
+                                        "personType": "NATURAL_PERSON",
+                                        "givenName": ${representativeGivenName},
+                                        "familyName": ${representativeFamilyName}
+                                    },
+                                   "contact.uuid": ${Contact: Erbengemeinschaft %{givenNameOfDeceasedPerson} %{familyNameOfDeceasedPerson}}
+                                }
+                                """))
+                        .reportWithResponse().expecting(CREATED).expecting(JSON)
+        )
+                .extractUuidAlias("holder.uuid", "Person: %{representativeGivenName} %{representativeFamilyName}");
 
         // outro: die Erbengemeinschaft hat eine Frist von 6 Monaten, um die Mitgliedschaft einer Person zu übertragen
         // →nächster "Drecksfall"
@@ -120,20 +100,44 @@ public class ReplaceDeceasedPartnerWithCommunityOfHeirs extends UseCase<ReplaceD
                 "Verify the Updated Partner",
                 () -> httpGet("/api/hs/office/partners/%{partnerNumber}")
                         .expecting(OK).expecting(JSON).expectObject(),
-                path("partnerRel.holder.tradeName").contains("Erbengemeinschaft %{givenNameOfDeceasedPerson} %{familyNameOfDeceasedPerson}")
+                path("partnerRel.holder.tradeName").contains(
+                        "Erbengemeinschaft %{givenNameOfDeceasedPerson} %{familyNameOfDeceasedPerson}"),
+                path("partnerRel.contact.postalAddress").lenientlyContainsJson("§{communityOfHeirsPostalAddress}"),
+                path("partnerRel.contact.phoneNumbers.office").contains("%{communityOfHeirsOfficePhoneNumber}"),
+                path("partnerRel.contact.emailAddresses.main").contains("%{communityOfHeirsEmailAddress}")
         );
 
-        // TODO.test: Verify the EX_PARTNER-Relation, once we fixed the anchor problem, see HsOfficePartnerController
-        // (net.hostsharing.hsadminng.hs.office.partner.HsOfficePartnerController.optionallyCreateExPartnerRelation)
+        verify(
+                "Verify the Ex-Partner-Relation",
+                () -> httpGet(
+                        "/api/hs/office/relations?relationType=EX_PARTNER&personUuid=%{Person: %{givenNameOfDeceasedPerson} %{familyNameOfDeceasedPerson}}")
+                        .expecting(OK).expecting(JSON).expectArrayElements(1),
+                path("[0].anchor.tradeName").contains(
+                        "Erbengemeinschaft %{givenNameOfDeceasedPerson} %{familyNameOfDeceasedPerson}")
+        );
 
         verify(
                 "Verify the Representative-Relation",
-                () -> httpGet("/api/hs/office/relations?relationType=REPRESENTATIVE&personUuid=%{Person: %{representativeGivenName} %{representativeFamilyName}}")
+                () -> httpGet(
+                        "/api/hs/office/relations?relationType=REPRESENTATIVE&personUuid=%{Person: Erbengemeinschaft %{givenNameOfDeceasedPerson} %{familyNameOfDeceasedPerson}}")
                         .expecting(OK).expecting(JSON).expectArrayElements(1),
-                path("[0].anchor.tradeName").contains("Erbengemeinschaft %{givenNameOfDeceasedPerson} %{familyNameOfDeceasedPerson}"),
-                path("[0].holder.familyName").contains("%{representativeFamilyName}")
+                path("[0].anchor.tradeName").contains(
+                        "Erbengemeinschaft %{givenNameOfDeceasedPerson} %{familyNameOfDeceasedPerson}"),
+                path("[0].holder.familyName").contains("%{representativeFamilyName}"),
+                path("[0].contact.postalAddress").lenientlyContainsJson("§{communityOfHeirsPostalAddress}"),
+                path("[0].contact.phoneNumbers.office").contains("%{communityOfHeirsOfficePhoneNumber}"),
+                path("[0].contact.emailAddresses.main").contains("%{communityOfHeirsEmailAddress}")
         );
 
-        // TODO.test: Verify Debitor, Membership, Coop-Shares and Coop-Assets once implemented
+        verify(
+                "Verify the Debitor-Relation",
+                () -> httpGet(
+                        "/api/hs/office/debitors?partnerNumber=%{partnerNumber}")
+                        .expecting(OK).expecting(JSON).expectArrayElements(1),
+                path("[0].debitorRel.anchor.tradeName").contains(
+                        "Erbengemeinschaft %{givenNameOfDeceasedPerson} %{familyNameOfDeceasedPerson}"),
+                path("[0].debitorRel.holder.tradeName").contains(
+                        "Erbengemeinschaft %{givenNameOfDeceasedPerson} %{familyNameOfDeceasedPerson}")
+        );
     }
 }
diff --git a/src/test/java/net/hostsharing/hsadminng/hs/scenarios/PathAssertion.java b/src/test/java/net/hostsharing/hsadminng/hs/scenarios/PathAssertion.java
index 4a51932e..04ec0fe9 100644
--- a/src/test/java/net/hostsharing/hsadminng/hs/scenarios/PathAssertion.java
+++ b/src/test/java/net/hostsharing/hsadminng/hs/scenarios/PathAssertion.java
@@ -5,6 +5,7 @@ import net.hostsharing.hsadminng.hs.scenarios.UseCase.HttpResponse;
 import java.util.function.Consumer;
 
 import static net.hostsharing.hsadminng.hs.scenarios.TemplateResolver.Resolver.DROP_COMMENTS;
+import static net.hostsharing.hsadminng.test.JsonMatcher.lenientlyEquals;
 import static org.junit.jupiter.api.Assertions.fail;
 
 public class PathAssertion {
@@ -27,6 +28,18 @@ public class PathAssertion {
         };
     }
 
+    @SuppressWarnings({ "unchecked", "rawtypes" })
+    public Consumer<UseCase.HttpResponse> lenientlyContainsJson(final String resolvableValue) {
+        return response -> {
+            try {
+                lenientlyEquals(ScenarioTest.resolve(resolvableValue, DROP_COMMENTS)).matches(response.getFromBody(path)) ;
+            } catch (final AssertionError e) {
+                // without this, the error message is often lacking important context
+                fail(e.getMessage() + " in `path(\"" + path +  "\").contains(\"" + resolvableValue + "\")`" );
+            }
+        };
+    }
+
     public Consumer<HttpResponse> doesNotExist() {
         return response -> {
             try {
diff --git a/src/test/java/net/hostsharing/hsadminng/hs/scenarios/TemplateResolver.java b/src/test/java/net/hostsharing/hsadminng/hs/scenarios/TemplateResolver.java
index d28adb26..eb82d676 100644
--- a/src/test/java/net/hostsharing/hsadminng/hs/scenarios/TemplateResolver.java
+++ b/src/test/java/net/hostsharing/hsadminng/hs/scenarios/TemplateResolver.java
@@ -32,6 +32,12 @@ public class TemplateResolver {
                 return jsonQuoted(value);
             }
         },
+        JSON_OBJECT('§'){
+            @Override
+            String convert(final Object value, final Resolver resolver) {
+                return jsonObject(value);
+            }
+        },
         URI_ENCODED('&'){
             @Override
             String convert(final Object value, final Resolver resolver) {
@@ -213,4 +219,12 @@ public class TemplateResolver {
             default -> "\"" + value + "\"";
         };
     }
+
+    private static String jsonObject(final Object value) {
+        return switch (value) {
+            case null -> null;
+            case String string -> "{" + string.replace("\n", " ") + "}";
+            default -> throw new IllegalArgumentException("can not format " + value.getClass() + " (" + value + ") as JSON object");
+        };
+    }
 }
diff --git a/src/test/java/net/hostsharing/hsadminng/rbac/test/PatchUnitTestBase.java b/src/test/java/net/hostsharing/hsadminng/rbac/test/PatchUnitTestBase.java
index f2b7e8bb..82d133e4 100644
--- a/src/test/java/net/hostsharing/hsadminng/rbac/test/PatchUnitTestBase.java
+++ b/src/test/java/net/hostsharing/hsadminng/rbac/test/PatchUnitTestBase.java
@@ -19,7 +19,7 @@ import static org.assertj.core.api.Assumptions.assumeThat;
 public abstract class PatchUnitTestBase<R, E> {
 
     @Test
-    void willPatchNoProperty() {
+    protected void willPatchNoProperty() {
         // given
         final var givenEntity = newInitialEntity();
         final var patchResource = newPatchResource();
@@ -73,7 +73,7 @@ public abstract class PatchUnitTestBase<R, E> {
 
     @ParameterizedTest
     @MethodSource("propertyTestCases")
-    void willThrowExceptionIfNotNullableValueIsNull(final Property<R, Object, E, Object> testCase) {
+    protected void willThrowExceptionIfNotNullableValueIsNull(final Property<R, Object, E, Object> testCase) {
         assumeThat(testCase instanceof JsonNullableProperty).isTrue();
         assumeThat(testCase.nullable).isFalse();
 
@@ -94,7 +94,7 @@ public abstract class PatchUnitTestBase<R, E> {
 
     @ParameterizedTest
     @MethodSource("propertyTestCases")
-    void willPatchOnlyGivenPropertyToNull(final Property<R, Object, E, Object> testCase) {
+    protected void willPatchOnlyGivenPropertyToNull(final Property<R, Object, E, Object> testCase) {
         assumeThat(testCase.nullable).isTrue();
 
         // given
@@ -113,7 +113,7 @@ public abstract class PatchUnitTestBase<R, E> {
 
     @ParameterizedTest
     @MethodSource("propertyTestCases")
-    void willNotPatchIfGivenPropertyNotGiven(final Property<R, Object, E, Object> testCase) {
+    protected void willNotPatchIfGivenPropertyNotGiven(final Property<R, Object, E, Object> testCase) {
 
         // given
         final var givenEntity = newInitialEntity();