diff --git a/vorgang-manager-interface/src/main/protobuf/vorgang.model.proto b/vorgang-manager-interface/src/main/protobuf/vorgang.model.proto
index 479c9ead1e477c2aa7f07588a4df5b2ae02f08ff..ffe4cc45c2feb899ba7cd64424588035cf4f3770 100644
--- a/vorgang-manager-interface/src/main/protobuf/vorgang.model.proto
+++ b/vorgang-manager-interface/src/main/protobuf/vorgang.model.proto
@@ -214,7 +214,7 @@ message GrpcCreateCollaborationRequestData {
   string vorgangId = 1;
   int32 collaborationLevel = 2;
   reserved 3;
-  string organisationsEinheitId = 4;
+  string organisationEinheitId = 4;
 }
 
 message GrpcCreateCollaborationVorgangResponse {
diff --git a/vorgang-manager-server/src/main/java/de/ozgcloud/vorgang/collaboration/CreateCollaborationVorgangRequestMapper.java b/vorgang-manager-server/src/main/java/de/ozgcloud/vorgang/collaboration/CreateCollaborationVorgangRequestMapper.java
index e7d98214f47767f8e504319062e735e1f1542162..413ae397c7278b3351fba46dafb843e2bc1abd32 100644
--- a/vorgang-manager-server/src/main/java/de/ozgcloud/vorgang/collaboration/CreateCollaborationVorgangRequestMapper.java
+++ b/vorgang-manager-server/src/main/java/de/ozgcloud/vorgang/collaboration/CreateCollaborationVorgangRequestMapper.java
@@ -33,5 +33,6 @@ import de.ozgcloud.vorgang.vorgang.GrpcCreateCollaborationRequestData;
 public interface CreateCollaborationVorgangRequestMapper {
 
 	@Mapping(target = "vorgang", ignore = true)
+	@Mapping(target = "organisationsEinheitId", source = "organisationEinheitId")
 	CreateCollaborationVorgangRequest mapFrom(GrpcCreateCollaborationRequestData grpcCollaborationRequest);
 }
diff --git a/vorgang-manager-server/src/test/java/de/ozgcloud/vorgang/collaboration/CollaborationITCase.java b/vorgang-manager-server/src/test/java/de/ozgcloud/vorgang/collaboration/CollaborationITCase.java
index c09938f11e6ae55f3552995e760a2b43b0d541bd..dcd94d7fef449ab06e185ca9214ca64d45f72a33 100644
--- a/vorgang-manager-server/src/test/java/de/ozgcloud/vorgang/collaboration/CollaborationITCase.java
+++ b/vorgang-manager-server/src/test/java/de/ozgcloud/vorgang/collaboration/CollaborationITCase.java
@@ -49,11 +49,8 @@ import org.mockito.Captor;
 import org.mockito.Mock;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.beans.factory.annotation.Qualifier;
-import org.springframework.boot.autoconfigure.ImportAutoConfiguration;
 import org.springframework.boot.test.context.SpringBootTest;
-import org.springframework.boot.test.context.TestConfiguration;
 import org.springframework.boot.test.mock.mockito.MockBean;
-import org.springframework.context.annotation.Bean;
 import org.springframework.data.mongodb.core.MongoOperations;
 import org.springframework.data.mongodb.core.query.Criteria;
 import org.springframework.data.mongodb.core.query.Query;
@@ -74,6 +71,7 @@ import de.ozgcloud.collaboration.CollaborationService;
 import de.ozgcloud.collaboration.CollaborationServiceGrpc.CollaborationServiceBlockingStub;
 import de.ozgcloud.collaboration.GrpcGetFileContentRequest;
 import de.ozgcloud.collaboration.fachstelle.Fachstelle.FachstelleType;
+import de.ozgcloud.collaboration.fachstelle.FachstelleService;
 import de.ozgcloud.collaboration.request.CollaborationRequestId;
 import de.ozgcloud.collaboration.request.CollaborationRequestServiceGrpc.CollaborationRequestServiceBlockingStub;
 import de.ozgcloud.collaboration.request.GrpcFindRequestsRequest;
@@ -103,17 +101,13 @@ import de.ozgcloud.vorgang.vorgang.VorgangTestFactory;
 import de.ozgcloud.vorgang.vorgang.ZustaendigeStelleTestFactory;
 import io.grpc.Status;
 import io.grpc.StatusRuntimeException;
-import net.devh.boot.grpc.client.autoconfigure.GrpcClientAutoConfiguration;
 import net.devh.boot.grpc.client.inject.GrpcClient;
-import net.devh.boot.grpc.server.autoconfigure.GrpcServerAutoConfiguration;
-import net.devh.boot.grpc.server.autoconfigure.GrpcServerFactoryAutoConfiguration;
 
 @SpringBootTest(properties = {
 		"grpc.server.inProcessName=test",
 		"grpc.client.vorgang-manager.address=in-process:test",
 		"grpc.client.ozgcloud-command-manager.address=in-process:test",
 		"grpc.client.file-manager.address=in-process:test",
-		"grpc.client.zufi-manager.address=in-process:test",
 		"grpc.client.inProcess.address=in-process:test",
 		"grpc.client.pluto.address=in-process:test"
 })
@@ -125,7 +119,6 @@ class CollaborationITCase {
 	private static final String FIELD_COLLABORATION_VORGANG_ID = "collaborationVorgangId";
 	private static final String TITEL = "Collaboration Vorgang";
 	private static final String BESCHREIBUNG = "Beschreibung der Anfrage";
-	private static final String ZUFI_ID = UUID.randomUUID().toString();
 
 	@Autowired
 	private CommandService commandService;
@@ -145,6 +138,8 @@ class CollaborationITCase {
 	private OzgCloudUserProfile ozgCloudUserProfile;
 	@MockBean
 	private OzgCloudClientAttributeMapper clientAttributeMapper;
+	@MockBean
+	private FachstelleService fachstelleService;
 
 	private String vorgangId;
 
@@ -225,24 +220,6 @@ class CollaborationITCase {
 		}
 	}
 
-	private CreateCommandRequest buildCreateCollaborationVorgangCommand(String vorgangId, int collaborationLevel) {
-		return buildCreateCollaborationVorgangCommand(vorgangId, collaborationLevel, ZUFI_ID);
-	}
-
-	private CreateCommandRequest buildCreateCollaborationVorgangCommand(String vorgangId, int collaborationLevel, String zustaendigeStelleId) {
-		return CreateCommandRequest.builder()
-				.callContext(CallContext.builder().client("test").build())
-				.vorgangId(vorgangId)
-				.relationId(vorgangId)
-				.order("CREATE_COLLABORATION_REQUEST")
-				.bodyObject(Map.of(
-						"titel", TITEL,
-						"beschreibung", BESCHREIBUNG,
-						"collaborationLevel", collaborationLevel,
-						"zustaendigeStelle", zustaendigeStelleId))
-				.build();
-	}
-
 	private List<VorgangAttachedItem> loadCollaborationRequest(String vorgangId) {
 		var query = new Query(new Criteria().andOperator(
 				Criteria.where(VorgangAttachedItem.FIELDNAME_VORGANG_ID).is(vorgangId),
@@ -258,11 +235,13 @@ class CollaborationITCase {
 
 	@Nested
 	class TestCreateCollaborationVorgang {
+		public static final String ORGANISATIONS_EINHEIT_ID = UUID.randomUUID().toString();
 
 		@BeforeEach
 		void init() {
 			when(ozgCloudUserProfile.getId()).thenReturn(OzgCloudUserId.from(CommandTestFactory.CREATED_BY));
 			when(collaborationOzgCloudUserProfileService.getById(any())).thenReturn(ozgCloudUserProfile);
+			when(fachstelleService.getOrganisationEinheit(FachstelleTestFactory.TECHNICAL_ID)).thenReturn(FachstelleTestFactory.create());
 		}
 
 		@Test
@@ -286,14 +265,14 @@ class CollaborationITCase {
 			assertThat(collaborationVorgang.getHeader()).extracting(VorgangHead::getCollaborationLevel)
 					.isEqualTo(CreateCollaborationVorgangRequestTestFactory.COLLABORATION_LEVEL);
 			assertThat(collaborationVorgang.getHeader()).extracting(VorgangHead::getOrganisationsEinheitId)
-					.isEqualTo(OrganisationsEinheitGrpcServiceMock.ORGANISATIONS_EINHEIT_ID);
+					.isEqualTo(FachstelleTestFactory.SUBJECT_ID);
 			assertThat(collaborationVorgang.getClientAttributes()).isEmpty();
 		}
 
 		private Command createCommand() {
 			return commandService.createCommand(
 					buildCreateCollaborationVorgangCommand(vorgangId,
-							CreateCollaborationVorgangRequestTestFactory.COLLABORATION_LEVEL, OrganisationsEinheitGrpcServiceMock.ID));
+							CreateCollaborationVorgangRequestTestFactory.COLLABORATION_LEVEL, FachstelleTestFactory.TECHNICAL_ID));
 		}
 
 		private Vorgang loadCollaborationVorgang(String sourceVorgangId) {
@@ -317,6 +296,7 @@ class CollaborationITCase {
 			void init() {
 				when(ozgCloudUserProfile.getId()).thenReturn(OzgCloudUserId.from(CommandTestFactory.CREATED_BY));
 				when(collaborationOzgCloudUserProfileService.getById(any())).thenReturn(ozgCloudUserProfile);
+				when(fachstelleService.getExterneFachstelle(FachstelleTestFactory.TECHNICAL_ID)).thenReturn(FachstelleTestFactory.create());
 			}
 
 			@Test
@@ -338,7 +318,7 @@ class CollaborationITCase {
 
 				verify(postfachRemoteService).sendMessage(postfachNachrichtCaptor.capture());
 				assertThat(postfachNachrichtCaptor.getValue().getPostfachAddress()).extracting(PostfachAddress::getIdentifier)
-						.hasToString(FachstelleGrpcServiceMock.MUK_ID);
+						.hasToString(FachstelleTestFactory.SUBJECT_ID);
 			}
 
 			@Test
@@ -367,10 +347,24 @@ class CollaborationITCase {
 
 		private Command createCommand() {
 			return commandService
-					.createCommand(buildCreateCollaborationVorgangCommand(vorgangId, COLLABORATION_LEVEL, FachstelleGrpcServiceMock.ZUFI_ID));
+					.createCommand(buildCreateCollaborationVorgangCommand(vorgangId, COLLABORATION_LEVEL, FachstelleTestFactory.TECHNICAL_ID));
 		}
 	}
 
+	private CreateCommandRequest buildCreateCollaborationVorgangCommand(String vorgangId, int collaborationLevel, String zustaendigeStelleId) {
+		return CreateCommandRequest.builder()
+				.callContext(CallContext.builder().client("test").build())
+				.vorgangId(vorgangId)
+				.relationId(vorgangId)
+				.order("CREATE_COLLABORATION_REQUEST")
+				.bodyObject(Map.of(
+						"titel", TITEL,
+						"beschreibung", BESCHREIBUNG,
+						"collaborationLevel", collaborationLevel,
+						"zustaendigeStelle", zustaendigeStelleId))
+				.build();
+	}
+
 	@DisplayName("Collaboration requests")
 	@Nested
 	class TestCollaborationRequests {
@@ -386,9 +380,9 @@ class CollaborationITCase {
 		public static final String COLLABORATION_VORGANG_ID = UUID.randomUUID().toString();
 		public static final int COLLABORATION_LEVEL = 1;
 
-		private static final String TECHNICAL_ID = OrganisationsEinheitGrpcServiceMock.ID;
-		private static final String SUBJECT_ID = OrganisationsEinheitGrpcServiceMock.ORGANISATIONS_EINHEIT_ID;
-		private static final FachstelleType TYPE = FachstelleType.ORGANISATIONS_EINHEIT;
+		private static final String TECHNICAL_ID = FachstelleTestFactory.TECHNICAL_ID;
+		private static final String SUBJECT_ID = FachstelleTestFactory.SUBJECT_ID;
+		private static final FachstelleType TYPE = FachstelleType.ORGANISATION_EINHEIT;
 
 		private final Vorgang vorgang = VorgangTestFactory.create();
 
@@ -499,21 +493,4 @@ class CollaborationITCase {
 		}
 	}
 
-	@TestConfiguration
-	@ImportAutoConfiguration({
-			GrpcServerAutoConfiguration.class,
-			GrpcServerFactoryAutoConfiguration.class,
-			GrpcClientAutoConfiguration.class })
-	static class ZufiServerTestConfiguration {
-
-		@Bean
-		FachstelleGrpcServiceMock fachstelleGrpcServiceMock() {
-			return new FachstelleGrpcServiceMock();
-		}
-
-		@Bean
-		OrganisationsEinheitGrpcServiceMock organisationsEinheitGrpcServiceMock() {
-			return new OrganisationsEinheitGrpcServiceMock();
-		}
-	}
 }
\ No newline at end of file
diff --git a/vorgang-manager-server/src/test/java/de/ozgcloud/vorgang/collaboration/FachstelleGrpcServiceMock.java b/vorgang-manager-server/src/test/java/de/ozgcloud/vorgang/collaboration/FachstelleGrpcServiceMock.java
deleted file mode 100644
index 48ef451cb7f2c513fe9089f39e5e0d261fa5d260..0000000000000000000000000000000000000000
--- a/vorgang-manager-server/src/test/java/de/ozgcloud/vorgang/collaboration/FachstelleGrpcServiceMock.java
+++ /dev/null
@@ -1,51 +0,0 @@
-package de.ozgcloud.vorgang.collaboration;
-
-import java.util.UUID;
-
-import com.thedeanda.lorem.LoremIpsum;
-
-import de.ozgcloud.zufi.grpc.fachstelle.FachstelleServiceGrpc.FachstelleServiceImplBase;
-import de.ozgcloud.zufi.grpc.fachstelle.GrpcFachstelle;
-import de.ozgcloud.zufi.grpc.fachstelle.GrpcFachstelleGetRequest;
-import de.ozgcloud.zufi.grpc.fachstelle.GrpcFachstelleGetResponse;
-import io.grpc.stub.StreamObserver;
-import net.devh.boot.grpc.server.service.GrpcService;
-
-@GrpcService
-class FachstelleGrpcServiceMock extends FachstelleServiceImplBase {
-
-	static final String ZUFI_ID = UUID.randomUUID().toString();
-	static final String MUK_ID = UUID.randomUUID().toString();
-	public static final String FIRMEN_NAME = LoremIpsum.getInstance().getWords(2);
-	public static final String RECHTSFORM = LoremIpsum.getInstance().getWords(1);
-	public static final String RECHTSFORM_TEXT = LoremIpsum.getInstance().getWords(1);
-	public static final String REGISTER_NUMMER = UUID.randomUUID().toString();
-	public static final String REGISTER_ART = LoremIpsum.getInstance().getWords(1);
-	public static final String EMAIL_ADRESSE = LoremIpsum.getInstance().getEmail();
-	public static final String ANSCHRIFT = LoremIpsum.getInstance().getWords(5);
-
-	@Override
-	public void getById(GrpcFachstelleGetRequest request, StreamObserver<GrpcFachstelleGetResponse> responseObserver) {
-		if (request.getId().equals(ZUFI_ID)) {
-			responseObserver.onNext(buildFachstelleGetResponse());
-			responseObserver.onCompleted();
-		} else {
-			throw new AssertionError("Expected zufiId %s. But actual zufiId was %s.".formatted(ZUFI_ID, request.getId()));
-		}
-	}
-
-	GrpcFachstelleGetResponse buildFachstelleGetResponse() {
-		return GrpcFachstelleGetResponse.newBuilder()
-				.setFachstelle(GrpcFachstelle.newBuilder()
-						.setId(ZUFI_ID)
-						.setMukId(MUK_ID)
-						.setFirmenName(FIRMEN_NAME)
-						.setRechtsform(RECHTSFORM)
-						.setRechtsformText(RECHTSFORM_TEXT)
-						.setRegisterNummer(REGISTER_NUMMER)
-						.setRegisterArt(REGISTER_ART)
-						.setEmailAdresse(EMAIL_ADRESSE)
-						.setAnschrift(ANSCHRIFT))
-				.build();
-	}
-}
diff --git a/vorgang-manager-server/src/test/java/de/ozgcloud/vorgang/collaboration/FachstelleTestFactory.java b/vorgang-manager-server/src/test/java/de/ozgcloud/vorgang/collaboration/FachstelleTestFactory.java
new file mode 100644
index 0000000000000000000000000000000000000000..fb7d82bf3137a889aebf6d7e3e7f4b6aecd6cb17
--- /dev/null
+++ b/vorgang-manager-server/src/test/java/de/ozgcloud/vorgang/collaboration/FachstelleTestFactory.java
@@ -0,0 +1,26 @@
+package de.ozgcloud.vorgang.collaboration;
+
+import java.util.UUID;
+
+import de.ozgcloud.collaboration.fachstelle.Fachstelle;
+import de.ozgcloud.collaboration.fachstelle.Fachstelle.FachstelleBuilder;
+import de.ozgcloud.collaboration.fachstelle.Fachstelle.FachstelleType;
+
+public class FachstelleTestFactory {
+
+	public static final String SUBJECT_ID = UUID.randomUUID().toString();
+	public static final String TECHNICAL_ID = UUID.randomUUID().toString();
+	public static final FachstelleType TYPE = FachstelleType.ORGANISATION_EINHEIT;
+
+	public static Fachstelle create() {
+		return createBuilder().build();
+	}
+
+	public static FachstelleBuilder createBuilder() {
+		return Fachstelle.builder()
+				.subjectId(SUBJECT_ID)
+				.technicalId(TECHNICAL_ID)
+				.type(TYPE);
+	}
+
+}
diff --git a/vorgang-manager-server/src/test/java/de/ozgcloud/vorgang/collaboration/GrpcCreateCollaborationRequestDataTestFactory.java b/vorgang-manager-server/src/test/java/de/ozgcloud/vorgang/collaboration/GrpcCreateCollaborationRequestDataTestFactory.java
index adbccf0472dd286fd429d352a7afe01d98d70749..74da3279207eee66dabaee50c77e185d7073da78 100644
--- a/vorgang-manager-server/src/test/java/de/ozgcloud/vorgang/collaboration/GrpcCreateCollaborationRequestDataTestFactory.java
+++ b/vorgang-manager-server/src/test/java/de/ozgcloud/vorgang/collaboration/GrpcCreateCollaborationRequestDataTestFactory.java
@@ -35,7 +35,7 @@ public class GrpcCreateCollaborationRequestDataTestFactory {
 	public static GrpcCreateCollaborationRequestData.Builder createBuilder() {
 		return GrpcCreateCollaborationRequestData.newBuilder()
 				.setVorgangId(VorgangTestFactory.ID)
-				.setOrganisationsEinheitId(CreateCollaborationVorgangRequestTestFactory.ORGANISATIONSEINHEIT_ID)
+				.setOrganisationEinheitId(CreateCollaborationVorgangRequestTestFactory.ORGANISATIONSEINHEIT_ID)
 				.setCollaborationLevel(CreateCollaborationVorgangRequestTestFactory.COLLABORATION_LEVEL);
 	}
 }
diff --git a/vorgang-manager-server/src/test/java/de/ozgcloud/vorgang/collaboration/OrganisationsEinheitGrpcServiceMock.java b/vorgang-manager-server/src/test/java/de/ozgcloud/vorgang/collaboration/OrganisationsEinheitGrpcServiceMock.java
deleted file mode 100644
index 113f42dea871147a33ca1ae4902095903e4cba59..0000000000000000000000000000000000000000
--- a/vorgang-manager-server/src/test/java/de/ozgcloud/vorgang/collaboration/OrganisationsEinheitGrpcServiceMock.java
+++ /dev/null
@@ -1,59 +0,0 @@
-package de.ozgcloud.vorgang.collaboration;
-
-import java.util.Random;
-import java.util.UUID;
-
-import com.thedeanda.lorem.LoremIpsum;
-
-import de.ozgcloud.zufi.grpc.organisationseinheit.GrpcAnschrift;
-import de.ozgcloud.zufi.grpc.organisationseinheit.GrpcOrganisationsEinheit;
-import de.ozgcloud.zufi.grpc.organisationseinheit.GrpcOrganisationsEinheitGetRequest;
-import de.ozgcloud.zufi.grpc.organisationseinheit.GrpcOrganisationsEinheitGetResponse;
-import de.ozgcloud.zufi.grpc.organisationseinheit.GrpcXzufiId;
-import de.ozgcloud.zufi.grpc.organisationseinheit.OrganisationsEinheitServiceGrpc.OrganisationsEinheitServiceImplBase;
-import io.grpc.stub.StreamObserver;
-import net.devh.boot.grpc.server.service.GrpcService;
-
-@GrpcService
-public class OrganisationsEinheitGrpcServiceMock extends OrganisationsEinheitServiceImplBase {
-	public static final String ID = UUID.randomUUID().toString();
-	public static final String ORGANISATIONS_EINHEIT_ID = UUID.randomUUID().toString();
-	public static final String SCHEME_AGENCY_ID = UUID.randomUUID().toString();
-	public static final GrpcXzufiId XZUFI_ID = GrpcXzufiId.newBuilder().setId(ORGANISATIONS_EINHEIT_ID).setSchemeAgencyId(SCHEME_AGENCY_ID).build();
-	public static final String NAME = LoremIpsum.getInstance().getName();
-	public static final String SYNONYME = LoremIpsum.getInstance().getWords(5);
-	public static final String PLZ = LoremIpsum.getInstance().getZipCode();
-	public static final String ORT = LoremIpsum.getInstance().getCity();
-	public static final String STRASSE = LoremIpsum.getInstance().getWords(2);
-	public static final String HAUSNUMMER = String.valueOf(new Random().nextInt());
-	public static final GrpcAnschrift ANSCHRIFT = GrpcAnschrift.newBuilder()
-			.setStrasse(STRASSE)
-			.setHausnummer(HAUSNUMMER)
-			.setPlz(PLZ)
-			.setOrt(ORT)
-			.build();
-	public static final String VORGANG_MANAGER_ADDRESS = LoremIpsum.getInstance().getUrl();
-
-	@Override
-	public void getById(GrpcOrganisationsEinheitGetRequest request, StreamObserver<GrpcOrganisationsEinheitGetResponse> responseObserver) {
-
-		if (request.getId().equals(ID)) {
-			responseObserver.onNext(buildOrganisationsEinheitGetResponse());
-			responseObserver.onCompleted();
-		} else {
-			throw new AssertionError("Expected id %s. But actual id was %s.".formatted(ID, request.getId()));
-		}
-	}
-
-	GrpcOrganisationsEinheitGetResponse buildOrganisationsEinheitGetResponse() {
-		return GrpcOrganisationsEinheitGetResponse.newBuilder().setOrganisationsEinheit(
-				GrpcOrganisationsEinheit.newBuilder()
-						.setId(ID)
-						.setName(NAME)
-						.setAnschrift(ANSCHRIFT)
-						.setVorgangManagerAddress(VORGANG_MANAGER_ADDRESS)
-						.setXzufiId(XZUFI_ID)
-						.build())
-				.build();
-	}
-}