Service principal account now shown as "Unknown User" in Team


My customer uses a service principal account to provision a team. This account was always invisibile in the member/owner list of the team. Now we see the account as "Unknown User" in a Team and even worse the team members see that an "Unknown User" joined the team (screenshot is in German):


Are there any recent changes to Teams or the Office 365 Group I should know of?

All advice is appreciated!

12 Replies

@arifC  We are seeing the same thing since this morning with every team that was created by a service account. No idea what happened, but probably something changed on the side of Microsoft 

Hello, we are facing the same issue in our organization.
Any update from Microsoft would be appreciated.

We have this behavior as well on our tenant.
All Teams are created with the Service Account, but the "unknown user" is only added in what looks like a random subset of the available Teams.

It is possible to remove the Service Account via Azure (it has owner rights). Functionality stays the same after that. So far as I know there is no reason for a service account to have owner rights in an Office365 Group. So it is strange that it is showing up now.

Even worse, the message "Unknow User Joined the Team", doesn't work in favor of a secure environment for our users.

@arifC +1, I also experienced the same behavior today as here: The SPN is shown as Unknown User now.


SPN is now shown as Unknown User (in Teams only)SPN is now shown as Unknown User (in Teams only)

Hi @arifC,

Microsoft has posted a new advisory under Service Health about the Unknown user in Teams. You can find it by looking for the ID "TM206109". This is how the message looks:



Let's hope that the upcoming hotfix will solve the issue!



@devjhorst and solution to this problem? I invited two guests to a team and they appear as "Unknown User"



Hello @EliasGro,


the bug related to service principal and unknown user in Teams should be fixed. According to your description, you are seeing "Unknown Users" when adding guests to a team which seems to be a different topic. I found a similar discussion here. Maybe you could check it out :grinning_face: 


I hope it helps.


For anyone still experiencing this. I had this today and turned out that the problem went away when I disabled the Skype for business license for the user.

Yip we are also still having this problem.


Looked for the TM Number but unable to find it under history as well.

We are getting the same issue, at the moment I am putting it down to a provisioning issue.


Our staff members can add a large bunch of users to the team they have created e.g. 25, then the last 5 when they search for them get a list of unknown_user.


However as tenant admin, I can go in and add the ones they can't do by hand without issue.

@e are experiencing the same issue, added a new user and we are unable to add the new user to any team since it resolves as unknown user

Muy buenos días también presentamos el mismo problema en nuestra organización y esto es lo que me muestra por favor equipo Microsoft nos ayuda con la solución.