diff --git a/src/models/creation/CreateUser.ts b/src/models/creation/CreateUser.ts
index 102919a..9595039 100644
--- a/src/models/creation/CreateUser.ts
+++ b/src/models/creation/CreateUser.ts
@@ -2,7 +2,7 @@ import * as argon2 from "argon2";
 import { IsEmail, IsOptional, IsPhoneNumber, IsString, IsUUID } from 'class-validator';
 import { getConnectionManager } from 'typeorm';
 import * as uuid from 'uuid';
-import { UsernameOrEmailNeededError } from '../../errors/UserErrors';
+import { UserGroupNotFoundError, UsernameOrEmailNeededError } from '../../errors/UserErrors';
 import { User } from '../entities/User';
 import { UserGroup } from '../entities/UserGroup';
 
@@ -24,8 +24,6 @@ export class CreateUser {
     @IsEmail()
     @IsString()
     email?: string;
-    // @IsArray()
-    // @IsInt()
     @IsOptional()
     groupId?: number[] | number
     @IsUUID("4")
@@ -39,14 +37,20 @@ export class CreateUser {
         }
 
         if (this.groupId) {
-            // TODO: link user groups
             if (Array.isArray(this.groupId)) {
-
+                let found_groups = []
+                this.groupId.forEach(async (g) => {
+                    const foundGroup = await getConnectionManager().get().getRepository(UserGroup).find({ id: g });
+                    if (foundGroup) {
+                        found_groups.push(foundGroup)
+                    } else {
+                        throw new UserGroupNotFoundError();
+                    }
+                });
+                newUser.groups = found_groups
             } else {
                 newUser.groups = await getConnectionManager().get().getRepository(UserGroup).find({ id: this.groupId });
             }
-        } else {
-            // throw new UserGroupNotFoundError();
         }
 
         const new_uuid = uuid.v4()