diff --git a/goofy-server/src/main/java/de/itvsh/goofy/RootController.java b/goofy-server/src/main/java/de/itvsh/goofy/RootController.java
index 24b91ceb97b3aedbd2376840f04c2a47ac3b51b7..f931023a603f2803a7b465cfc7a6c93181f676a7 100644
--- a/goofy-server/src/main/java/de/itvsh/goofy/RootController.java
+++ b/goofy-server/src/main/java/de/itvsh/goofy/RootController.java
@@ -16,6 +16,7 @@ import org.springframework.web.bind.annotation.RestController;
 import de.itvsh.goofy.common.ModelBuilder;
 import de.itvsh.goofy.common.downloadtoken.DownloadTokenController;
 import de.itvsh.goofy.common.user.CurrentUserService;
+import de.itvsh.goofy.common.user.UserId;
 import de.itvsh.goofy.common.user.UserProfileController;
 import de.itvsh.goofy.vorgang.VorgangController;
 
@@ -37,25 +38,21 @@ public class RootController {
 
 	@GetMapping
 	public EntityModel<RootResource> getRootResource() {
-		return ModelBuilder.fromEntity(new RootResource())//
-				.addLink(linkTo(RootController.class).withSelfRel()) //
-				.addLink(linkTo(VorgangController.class).withRel(REL_VORGAENGE))//
+		return ModelBuilder.fromEntity(new RootResource())
+				.addLink(linkTo(RootController.class).withSelfRel())
+				.addLink(linkTo(VorgangController.class).withRel(REL_VORGAENGE))
 				.addLink(linkTo(methodOn(UserProfileController.class).findUsers(null)).withRel(REL_SEARCH_USER))
 				.addLink(linkTo(DownloadTokenController.class).withRel(REL_DOWNLOAD_TOKEN))
 				.addLink(buildVorgangListByPageLink(REL_SEARCH, Optional.empty()))
-				.addLink(buildVorgangListByPageLink(REL_MY_VORGAENGE, Optional.of(getCurrentUserId())))
-				.addLink(buildVorgangListByPageLink(REL_SEARCH_MY_VORGAENGE, Optional.of(getCurrentUserId())))
+				.addLink(buildVorgangListByPageLink(REL_MY_VORGAENGE, Optional.of(currentUserService.getUserId())))
+				.addLink(buildVorgangListByPageLink(REL_SEARCH_MY_VORGAENGE, Optional.of(currentUserService.getUserId())))
 				.buildModel();
 	}
 
-	private Link buildVorgangListByPageLink(String linkRel, Optional<String> assignedTo) {
+	private Link buildVorgangListByPageLink(String linkRel, Optional<UserId> assignedTo) {
 		return linkTo(methodOn(VorgangController.class).getVorgangListByPage(0, null, null, assignedTo)).withRel(linkRel);
 	}
 
-	private String getCurrentUserId() {
-		return currentUserService.getUserId().toString();
-	}
-
 	class RootResource {
 
 		public String getVersion() {
diff --git a/goofy-server/src/main/java/de/itvsh/goofy/vorgang/FindVorgaengeHeaderRequestCriteria.java b/goofy-server/src/main/java/de/itvsh/goofy/vorgang/FindVorgaengeHeaderRequestCriteria.java
index b5d646762ad653274e8827e5d2ce7f60e7a85955..41e3591b026c7fc04d45315f96f0cfb7132059e8 100644
--- a/goofy-server/src/main/java/de/itvsh/goofy/vorgang/FindVorgaengeHeaderRequestCriteria.java
+++ b/goofy-server/src/main/java/de/itvsh/goofy/vorgang/FindVorgaengeHeaderRequestCriteria.java
@@ -2,6 +2,7 @@ package de.itvsh.goofy.vorgang;
 
 import java.util.Optional;
 
+import de.itvsh.goofy.common.user.UserId;
 import lombok.Builder;
 import lombok.Getter;
 
@@ -12,5 +13,5 @@ class FindVorgaengeHeaderRequestCriteria {
 	private int offset;
 	private Optional<String> searchBy;
 	private OrderBy orderBy;
-	private Optional<String> assignedTo;
+	private Optional<UserId> assignedTo;
 }
diff --git a/goofy-server/src/main/java/de/itvsh/goofy/vorgang/PageUtil.java b/goofy-server/src/main/java/de/itvsh/goofy/vorgang/PageUtil.java
index 5d9b21b98664a29746ce265f072d4380286a09bb..299b3b4c64baf063c3ff2c0f9fb1385580ee6f6f 100644
--- a/goofy-server/src/main/java/de/itvsh/goofy/vorgang/PageUtil.java
+++ b/goofy-server/src/main/java/de/itvsh/goofy/vorgang/PageUtil.java
@@ -2,6 +2,7 @@ package de.itvsh.goofy.vorgang;
 
 import java.util.Optional;
 
+import de.itvsh.goofy.common.user.UserId;
 import lombok.AccessLevel;
 import lombok.Builder;
 import lombok.Getter;
@@ -49,7 +50,7 @@ class PageUtil {
 		private long total;
 		private Optional<Integer> limit;
 		private Optional<String> searchBy;
-		private Optional<String> assignedTo;
+		private Optional<UserId> assignedTo;
 
 		int getPageSize() {
 			return limit.orElse(VORGANG_PAGE_SIZE);
diff --git a/goofy-server/src/main/java/de/itvsh/goofy/vorgang/VorgangController.java b/goofy-server/src/main/java/de/itvsh/goofy/vorgang/VorgangController.java
index f8ab5aede27adc50660bac61143baede44c9913c..fda847b438fc8c92d14ded14337842b437542925 100644
--- a/goofy-server/src/main/java/de/itvsh/goofy/vorgang/VorgangController.java
+++ b/goofy-server/src/main/java/de/itvsh/goofy/vorgang/VorgangController.java
@@ -12,6 +12,7 @@ import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.bind.annotation.RequestParam;
 import org.springframework.web.bind.annotation.RestController;
 
+import de.itvsh.goofy.common.user.UserId;
 import de.itvsh.goofy.vorgang.PageUtil.VorgangListPage;
 
 @RestController
@@ -31,7 +32,7 @@ public class VorgangController {
 
 	@GetMapping
 	public CollectionModel<EntityModel<Vorgang>> getVorgangListByPage(@RequestParam(defaultValue = "0") int page,
-			@RequestParam Optional<String> searchBy, @RequestParam Optional<Integer> limit, @RequestParam Optional<String> assignedTo) {
+			@RequestParam Optional<String> searchBy, @RequestParam Optional<Integer> limit, @RequestParam Optional<UserId> assignedTo) {
 		var vorgaengeHeaderResponse = vorgangService.findVorgaengeHeader(buildFindVorgaengeRequestCriteria(page, searchBy, limit, assignedTo));
 
 		var vorgangListPage = VorgangListPage.builder()
@@ -47,7 +48,7 @@ public class VorgangController {
 	}
 
 	FindVorgaengeHeaderRequestCriteria buildFindVorgaengeRequestCriteria(int page, Optional<String> searchBy, Optional<Integer> limit,
-			Optional<String> assignedTo) {
+			Optional<UserId> assignedTo) {
 		return FindVorgaengeHeaderRequestCriteria.builder()
 				.limit(getLimitValue(limit))
 				.offset(calculateOffset(page, limit))
diff --git a/goofy-server/src/main/java/de/itvsh/goofy/vorgang/VorgangRemoteService.java b/goofy-server/src/main/java/de/itvsh/goofy/vorgang/VorgangRemoteService.java
index 1c8cfcd747cdfa16cedf9819e5ba6f39edb4f759..0c9cd04634886bb2d295c440e779182345bb2160 100644
--- a/goofy-server/src/main/java/de/itvsh/goofy/vorgang/VorgangRemoteService.java
+++ b/goofy-server/src/main/java/de/itvsh/goofy/vorgang/VorgangRemoteService.java
@@ -9,6 +9,7 @@ import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.stereotype.Service;
 
 import de.itvsh.goofy.common.user.CurrentUserService;
+import de.itvsh.goofy.common.user.UserId;
 import de.itvsh.goofy.common.user.UserRole;
 import de.itvsh.goofy.vorgang.Vorgang.VorgangStatus;
 import de.itvsh.ozg.pluto.vorgang.GrpcFilterBy;
@@ -84,9 +85,9 @@ class VorgangRemoteService {
 				.build();
 	}
 
-	GrpcFilterBy createFilterBy(Optional<String> assignedTo) {
+	GrpcFilterBy createFilterBy(Optional<UserId> assignedTo) {
 		var builder = GrpcFilterBy.newBuilder();
-		assignedTo.ifPresent(builder::setAssignedTo);
+		assignedTo.ifPresent(assignToId -> builder.setAssignedTo(assignToId.toString()));
 
 		if (userService.hasRole(UserRole.VERWALTUNG_POSTSTELLE)) {
 			return buildFilterByForPoststelle(builder);
diff --git a/goofy-server/src/main/resources/application.yml b/goofy-server/src/main/resources/application.yml
index 42d6e72bbe82a875101e19eb35c227707400bf17..7b3afc07d505ad5716a26df2e3066a4dfcfec818 100644
--- a/goofy-server/src/main/resources/application.yml
+++ b/goofy-server/src/main/resources/application.yml
@@ -16,8 +16,8 @@ spring:
       'ADJUST_DATES_TO_CONTEXT_TIME_ZONE': false
   servlet:
     multipart:
-      max-file-size: 20MB
-      max-request-size: 20MB
+      max-file-size: 40MB
+      max-request-size: 40MB
 
 server:
   http2:
diff --git a/goofy-server/src/test/java/de/itvsh/goofy/vorgang/FindVorgaengeRequestCriteriaTestFactory.java b/goofy-server/src/test/java/de/itvsh/goofy/vorgang/FindVorgaengeRequestCriteriaTestFactory.java
index f232e34558c185dfcd1b126fbe8ba54eee02defd..aee364baa45988ebdacf58e3d0b4dd39342af498 100644
--- a/goofy-server/src/test/java/de/itvsh/goofy/vorgang/FindVorgaengeRequestCriteriaTestFactory.java
+++ b/goofy-server/src/test/java/de/itvsh/goofy/vorgang/FindVorgaengeRequestCriteriaTestFactory.java
@@ -23,6 +23,6 @@ public class FindVorgaengeRequestCriteriaTestFactory {
 				.offset(OFFSET)
 				.searchBy(Optional.of(SEARCH_BY))
 				.orderBy(ORDER_BY)
-				.assignedTo(Optional.of(UserTestFactory.ID.toString()));
+				.assignedTo(Optional.of(UserTestFactory.ID));
 	}
 }
\ No newline at end of file
diff --git a/goofy-server/src/test/java/de/itvsh/goofy/vorgang/VorgangControllerTest.java b/goofy-server/src/test/java/de/itvsh/goofy/vorgang/VorgangControllerTest.java
index abb8086ef23389ed535af4fe5bce1b1cba7fcb96..054b6993c887a762fac1ede6a3c894ae8b916601 100644
--- a/goofy-server/src/test/java/de/itvsh/goofy/vorgang/VorgangControllerTest.java
+++ b/goofy-server/src/test/java/de/itvsh/goofy/vorgang/VorgangControllerTest.java
@@ -67,7 +67,7 @@ class VorgangControllerTest {
 			callEndpointWithParamsPageSearchAndLimit();
 
 			verify(controller).buildFindVorgaengeRequestCriteria(PAGE, Optional.of("test"), Optional.of(7),
-					Optional.of(UserTestFactory.ID.toString()));
+					Optional.of(UserTestFactory.ID));
 		}
 
 		@Test
diff --git a/goofy-server/src/test/java/de/itvsh/goofy/vorgang/VorgangModelAssemblerTest.java b/goofy-server/src/test/java/de/itvsh/goofy/vorgang/VorgangModelAssemblerTest.java
index d390ef98569fa05fca63e6c7c5ea8ea71b73c060..f6f29d75e6ad99050ed14a5bb952e226d34bccd2 100644
--- a/goofy-server/src/test/java/de/itvsh/goofy/vorgang/VorgangModelAssemblerTest.java
+++ b/goofy-server/src/test/java/de/itvsh/goofy/vorgang/VorgangModelAssemblerTest.java
@@ -86,7 +86,7 @@ class VorgangModelAssemblerTest {
 
 			@Test
 			void shouldContainsAssignedToParameter() {
-				var listPage = listPageBuilder.assignedTo(Optional.of(UserTestFactory.ID.toString()))
+				var listPage = listPageBuilder.assignedTo(Optional.of(UserTestFactory.ID))
 						.build();
 
 				var link = toCollectionModel(listPage).getLink(VorgangModelAssembler.REL_NEXT);
@@ -133,12 +133,12 @@ class VorgangModelAssemblerTest {
 
 			@Test
 			void shouldContainsAssignedToParameter() {
-				var listPage = listPageBuilder.assignedTo(Optional.of(UserTestFactory.ID.toString())).build();
+				var listPage = listPageBuilder.assignedTo(Optional.of(UserTestFactory.ID)).build();
 
 				var link = toCollectionModel(listPage).getLink(VorgangModelAssembler.REL_PREVIOUS);
 
 				assertThat(link).isPresent().get().extracting(Link::getHref)
-						.isEqualTo(BASE_PATH + "?page=1&assignedTo=" + UserTestFactory.ID.toString());
+						.isEqualTo(BASE_PATH + "?page=1&assignedTo=" + UserTestFactory.ID);
 			}
 		}
 
diff --git a/goofy-server/src/test/java/de/itvsh/goofy/vorgang/VorgangRemoteServiceTest.java b/goofy-server/src/test/java/de/itvsh/goofy/vorgang/VorgangRemoteServiceTest.java
index 59f366d25dafbecce44d05d1dc4926be9866f44e..36de788b14502b508757c48ea46d86d0b225de52 100644
--- a/goofy-server/src/test/java/de/itvsh/goofy/vorgang/VorgangRemoteServiceTest.java
+++ b/goofy-server/src/test/java/de/itvsh/goofy/vorgang/VorgangRemoteServiceTest.java
@@ -16,6 +16,7 @@ import org.mockito.Spy;
 
 import de.itvsh.goofy.common.user.CurrentUserService;
 import de.itvsh.goofy.common.user.GoofyUserTestFactory;
+import de.itvsh.goofy.common.user.UserId;
 import de.itvsh.goofy.common.user.UserRole;
 import de.itvsh.goofy.common.user.UserTestFactory;
 import de.itvsh.goofy.vorgang.Vorgang.VorgangStatus;
@@ -175,7 +176,7 @@ class VorgangRemoteServiceTest {
 
 			@Test
 			void shouldBeSetIfExists() {
-				var filterCriteria = callService(Optional.of(UserTestFactory.ID.toString()));
+				var filterCriteria = callService(Optional.of(UserTestFactory.ID));
 
 				assertThat(filterCriteria.getAssignedTo()).isEqualTo(UserTestFactory.ID.toString());
 			}
@@ -269,7 +270,7 @@ class VorgangRemoteServiceTest {
 			return callService(Optional.empty());
 		}
 
-		private GrpcFilterBy callService(Optional<String> assignedTo) {
+		private GrpcFilterBy callService(Optional<UserId> assignedTo) {
 			return service.createFilterBy(assignedTo);
 		}
 	}