diff --git a/router/src/main/java/de/ozgcloud/eingang/router/VorgangService.java b/router/src/main/java/de/ozgcloud/eingang/router/VorgangService.java
index 5a18d7ee752e594de92066f9b2480b34371f2e39..8a1d7855a7d8d6b41b3e0e73f650dc1a9da85345 100644
--- a/router/src/main/java/de/ozgcloud/eingang/router/VorgangService.java
+++ b/router/src/main/java/de/ozgcloud/eingang/router/VorgangService.java
@@ -28,6 +28,7 @@ import java.io.IOException;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.util.List;
+import java.util.Objects;
 import java.util.Optional;
 import java.util.stream.Stream;
 
@@ -102,6 +103,7 @@ public class VorgangService {
 	List<String> getOrganisationsEinheitIds(FormData formData) {
 		return formData.getZustaendigeStelles().stream()
 				.map(ZustaendigeStelle::getOrganisationseinheitenId)
+				.filter(Objects::nonNull)
 				.toList();
 	}
 
diff --git a/router/src/test/java/de/ozgcloud/eingang/router/VorgangServiceTest.java b/router/src/test/java/de/ozgcloud/eingang/router/VorgangServiceTest.java
index bd5ff001ac043671b3760e34a6921ac5c71b844e..d46aaa4dbcc5a406964d5a6bf8028441d43d599d 100644
--- a/router/src/test/java/de/ozgcloud/eingang/router/VorgangServiceTest.java
+++ b/router/src/test/java/de/ozgcloud/eingang/router/VorgangServiceTest.java
@@ -306,6 +306,19 @@ class VorgangServiceTest {
 	class TestGetOrganisationseinheitIds {
 		private final FormData preservedFormData = FormDataTestFactory.create();
 
+		@DisplayName("should filter out empty")
+		@Test
+		void shouldFilterOutEmpty() {
+			var formDataWithNullOrgId = FormDataTestFactory.createBuilder()
+					.clearZustaendigeStelles()
+					.zustaendigeStelles(List.of(ZustaendigeStelleTestFactory.createBuilder().organisationseinheitenId(null).build()))
+					.build();
+
+			var organisationseinheitIds = service.getOrganisationsEinheitIds(formDataWithNullOrgId);
+
+			assertThat(organisationseinheitIds).isEmpty();
+		}
+
 		@DisplayName("should return")
 		@Test
 		void shouldReturn() {
diff --git a/semantik-adapter/src/main/java/de/ozgcloud/eingang/semantik/common/ServiceKontoFactory.java b/semantik-adapter/src/main/java/de/ozgcloud/eingang/semantik/common/ServiceKontoFactory.java
index f41a76e44d5fc4c10f798ec3769425e08ab79d3a..8f9aa3d8b072f4a71c6f8a21c6d65716a19565b1 100644
--- a/semantik-adapter/src/main/java/de/ozgcloud/eingang/semantik/common/ServiceKontoFactory.java
+++ b/semantik-adapter/src/main/java/de/ozgcloud/eingang/semantik/common/ServiceKontoFactory.java
@@ -102,7 +102,12 @@ public class ServiceKontoFactory {
 	}
 
 	int getPostfachAddressType(Map<String, Object> restResponseName) {
-		return getMailboxType(restResponseName);
+		try {
+			return getMailboxType(restResponseName);
+		} catch (RuntimeException e) {
+			LOG.error("Error while getting mailbox type from rest response name", e);
+			return POSTFACH_ADDRESS_DEFAULT;
+		}
 	}
 
 	private Integer getMailboxType(Map<String, Object> restResponseName) {
diff --git a/semantik-adapter/src/test/java/de/ozgcloud/eingang/semantik/common/ServiceKontoFactoryTest.java b/semantik-adapter/src/test/java/de/ozgcloud/eingang/semantik/common/ServiceKontoFactoryTest.java
index 5f9fba08b38624af36a6c29a89c07020233b54e4..c62d3cd37b1d709b2c0e07a5f221733b8a2a03df 100644
--- a/semantik-adapter/src/test/java/de/ozgcloud/eingang/semantik/common/ServiceKontoFactoryTest.java
+++ b/semantik-adapter/src/test/java/de/ozgcloud/eingang/semantik/common/ServiceKontoFactoryTest.java
@@ -23,6 +23,7 @@
  */
 package de.ozgcloud.eingang.semantik.common;
 
+import static de.ozgcloud.eingang.semantik.common.ServiceKontoFactory.*;
 import static org.assertj.core.api.Assertions.*;
 import static org.mockito.ArgumentMatchers.*;
 import static org.mockito.Mockito.*;
@@ -34,6 +35,8 @@ import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.DisplayName;
 import org.junit.jupiter.api.Nested;
 import org.junit.jupiter.api.Test;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.ValueSource;
 import org.mockito.InjectMocks;
 import org.mockito.Spy;
 
@@ -41,10 +44,10 @@ import de.ozgcloud.eingang.common.formdata.FormData;
 import de.ozgcloud.eingang.common.formdata.FormDataUtils;
 import de.ozgcloud.eingang.common.formdata.PostfachAddressTestFactory;
 import de.ozgcloud.eingang.common.formdata.ServiceKonto;
+import de.ozgcloud.eingang.common.formdata.ServiceKonto.PostfachAddress;
 import de.ozgcloud.eingang.common.formdata.ServiceKonto.TrustLevel;
 import de.ozgcloud.eingang.common.formdata.ServiceKontoTestFactory;
 import de.ozgcloud.eingang.common.formdata.StringBasedIdentifier;
-import de.ozgcloud.eingang.common.formdata.ServiceKonto.PostfachAddress;
 
 class ServiceKontoFactoryTest {
 
@@ -104,8 +107,9 @@ class ServiceKontoFactoryTest {
 			@Nested
 			class TestWithRestResponseName {
 
+				@DisplayName("should call buildOsiPostfachV1Address")
 				@Test
-				void shouldCallBuildAddresses() {
+				void shouldCallBuildOsiPostfachV1Address() {
 					getPostfachAddresses();
 
 					verify(factory).buildOsiPostfachV1Address(any(), anyInt());
@@ -123,11 +127,62 @@ class ServiceKontoFactoryTest {
 					assertThat(addresses.get(0).getType()).isEqualTo(PostfachAddressTestFactory.POSTFACH_ADDRESS_TYPE);
 				}
 
+				@DisplayName("should return with postfach address type")
+				@ParameterizedTest
+				@ValueSource(ints = { 1, 2, 3 })
+				void shouldReturnWithPostfachAddressType(int postfachAddressType) {
+					var formDataWithPostfachAddressType = FormDataUtils.from(FORM_DATA)
+							.put(ServiceKontoFactory.REST_RESPONSE_NAME, List.of(Map.of(
+									ServiceKontoFactory.REST_RESPONSE_NAME_MEMBER_SCOPE,
+									List.of(Map.of(ServiceKontoFactory.REST_RESPONSE_NAME_MEMBER_SCOPE_MAILBOX_TYPE,
+											postfachAddressType))))
+							)
+							.build();
+
+					var addresses = buildServiceKonto(formDataWithPostfachAddressType);
+
+					var types = addresses.getPostfachAddresses()
+							.stream()
+							.map(PostfachAddress::getType)
+							.toList();
+					assertThat(types).containsExactly(postfachAddressType);
+				}
+
 				private List<PostfachAddress> getPostfachAddresses() {
 					return buildServiceKonto(FORM_DATA).getPostfachAddresses();
 				}
 			}
 
+			@DisplayName("with bad rest_response_name")
+			@Nested
+			class TestWithBadRestResponseName {
+
+				private final FormData formDataWithBadRestResponseName = FormDataUtils.from(FORM_DATA)
+						.put(ServiceKontoFactory.REST_RESPONSE_NAME, List.of(Map.of())).build();
+
+				@DisplayName("should call buildOsiPostfachV1Address")
+				@Test
+				void shouldCallBuildOsiPostfachV1Address() {
+					getPostfachAddresses();
+
+					verify(factory).buildOsiPostfachV1Address(any(), anyInt());
+				}
+
+				@DisplayName("should return postfach address with default type")
+				@Test
+				void shouldReturnPostfachAddressWithDefaultType() {
+					var addresses = getPostfachAddresses();
+
+					assertThat(addresses)
+							.extracting("type")
+							.containsExactly(POSTFACH_ADDRESS_DEFAULT);
+				}
+
+				private List<PostfachAddress> getPostfachAddresses() {
+					return buildServiceKonto(formDataWithBadRestResponseName).getPostfachAddresses();
+				}
+			}
+
 			@DisplayName("without rest_response_name")
 			@Nested
 			class TestWithoutRestResponseName {