diff --git a/api/src/routes/api/spec/group.spec.ts b/api/src/routes/api/spec/group.spec.ts
index fe1072e..56af21a 100644
--- a/api/src/routes/api/spec/group.spec.ts
+++ b/api/src/routes/api/spec/group.spec.ts
@@ -4,8 +4,13 @@ import { MongoMemoryServer } from 'mongodb-memory-server'
 import request from 'supertest'
 import appPromise from '../../../app'
 import { UserController, GroupController } from '../../../controllers/'
-import { generateAccessToken, saveTokensInDB } from '../../../utils'
-import { PUBLIC_GROUP_NAME } from '../../../model/Group'
+import {
+  generateAccessToken,
+  saveTokensInDB,
+  AuthProviderType
+} from '../../../utils'
+import Group, { PUBLIC_GROUP_NAME } from '../../../model/Group'
+import User from '../../../model/User'
 
 const clientId = 'someclientID'
 const adminUser = {
@@ -560,6 +565,46 @@ describe('group', () => {
         `Can't add/remove user to '${PUBLIC_GROUP_NAME}' group.`
       )
     })
+
+    it('should respond with Method Not Allowed if group is created by an external authProvider', async () => {
+      const dbGroup = await Group.create({
+        ...group,
+        authProvider: AuthProviderType.LDAP
+      })
+      const dbUser = await userController.createUser({
+        ...user,
+        username: 'ldapGroupUser'
+      })
+
+      const res = await request(app)
+        .post(`/SASjsApi/group/${dbGroup.groupId}/${dbUser.id}`)
+        .auth(adminAccessToken, { type: 'bearer' })
+        .send()
+        .expect(405)
+
+      expect(res.text).toEqual(
+        `Can't add/remove user to group created by external auth provider.`
+      )
+    })
+
+    it('should respond with Method Not Allowed if user is created by an external authProvider', async () => {
+      const dbGroup = await groupController.createGroup(group)
+      const dbUser = await User.create({
+        ...user,
+        username: 'ldapUser',
+        authProvider: AuthProviderType.LDAP
+      })
+
+      const res = await request(app)
+        .post(`/SASjsApi/group/${dbGroup.groupId}/${dbUser.id}`)
+        .auth(adminAccessToken, { type: 'bearer' })
+        .send()
+        .expect(405)
+
+      expect(res.text).toEqual(
+        `Can't add/remove user to group created by external auth provider.`
+      )
+    })
   })
 
   describe('RemoveUser', () => {
@@ -611,6 +656,46 @@ describe('group', () => {
       expect(res.body.groups).toEqual([])
     })
 
+    it('should respond with Method Not Allowed if group is created by an external authProvider', async () => {
+      const dbGroup = await Group.create({
+        ...group,
+        authProvider: AuthProviderType.LDAP
+      })
+      const dbUser = await userController.createUser({
+        ...user,
+        username: 'removeLdapGroupUser'
+      })
+
+      const res = await request(app)
+        .delete(`/SASjsApi/group/${dbGroup.groupId}/${dbUser.id}`)
+        .auth(adminAccessToken, { type: 'bearer' })
+        .send()
+        .expect(405)
+
+      expect(res.text).toEqual(
+        `Can't add/remove user to group created by external auth provider.`
+      )
+    })
+
+    it('should respond with Method Not Allowed if user is created by an external authProvider', async () => {
+      const dbGroup = await groupController.createGroup(group)
+      const dbUser = await User.create({
+        ...user,
+        username: 'removeLdapUser',
+        authProvider: AuthProviderType.LDAP
+      })
+
+      const res = await request(app)
+        .delete(`/SASjsApi/group/${dbGroup.groupId}/${dbUser.id}`)
+        .auth(adminAccessToken, { type: 'bearer' })
+        .send()
+        .expect(405)
+
+      expect(res.text).toEqual(
+        `Can't add/remove user to group created by external auth provider.`
+      )
+    })
+
     it('should respond with Unauthorized if access token is not present', async () => {
       const res = await request(app)
         .delete('/SASjsApi/group/123/123')
diff --git a/api/src/routes/api/spec/user.spec.ts b/api/src/routes/api/spec/user.spec.ts
index b2e000f..da8b829 100644
--- a/api/src/routes/api/spec/user.spec.ts
+++ b/api/src/routes/api/spec/user.spec.ts
@@ -4,7 +4,12 @@ import { MongoMemoryServer } from 'mongodb-memory-server'
 import request from 'supertest'
 import appPromise from '../../../app'
 import { UserController, GroupController } from '../../../controllers/'
-import { generateAccessToken, saveTokensInDB } from '../../../utils'
+import {
+  generateAccessToken,
+  saveTokensInDB,
+  AuthProviderType
+} from '../../../utils'
+import User from '../../../model/User'
 
 const clientId = 'someclientID'
 const adminUser = {
@@ -226,6 +231,36 @@ describe('user', () => {
         .expect(400)
     })
 
+    it('should respond with Method Not Allowed, when updating username of user created by an external auth provider', async () => {
+      const dbUser = await User.create({
+        ...user,
+        authProvider: AuthProviderType.LDAP
+      })
+      const accessToken = await generateAndSaveToken(dbUser!.id)
+      const newUsername = 'newUsername'
+
+      await request(app)
+        .patch(`/SASjsApi/user/${dbUser!.id}`)
+        .auth(accessToken, { type: 'bearer' })
+        .send({ username: newUsername })
+        .expect(405)
+    })
+
+    it('should respond with Method Not Allowed, when updating displayName of user created by an external auth provider', async () => {
+      const dbUser = await User.create({
+        ...user,
+        authProvider: AuthProviderType.LDAP
+      })
+      const accessToken = await generateAndSaveToken(dbUser!.id)
+      const newDisplayName = 'My new display Name'
+
+      await request(app)
+        .patch(`/SASjsApi/user/${dbUser!.id}`)
+        .auth(accessToken, { type: 'bearer' })
+        .send({ displayName: newDisplayName })
+        .expect(405)
+    })
+
     it('should respond with Unauthorized if access token is not present', async () => {
       const res = await request(app)
         .patch('/SASjsApi/user/1234')