Internal Teams user showing as External

Brass Contributor

We are experiencing strange behavior in Teams, sometimes few internal users are showing as external user. This is mostly happening in Teams Mobile app.


Any idea pls?

14 Replies

@krishna2320 , we experience the same issue.
How does your environment look like and in what mode is teams running?

We are still in hybrid with legacy Lync 2010 (proxy also used for federation), the tenant is in Teams island mode but some users are in Teams Only mode.
Would be helpful to understand if the issue is related to our setup or not.

Same here. Didn’t have time to do extensive debug on this.
It seems it started 1-2 months ago.

Did you open a support request to Microsoft?


We are experiencing the same issue on mobile devices. Has anybody resolved this yet?

@Mark_Taratoa unfortunately I can’t help, but just report we have same issue, it looks almost random, and occur only on mobile - a long term employee and O365/ Teams user suddenly show as (External)

@Fabian76  sorry for the delayed response, it's Teams Only Mode. we are completely online no Lync/SFB servers.

@Lars Jeppesen true, it happens once in a while not in every meeting.

@francorg  i did but they couldn't find anything.

thank you!

So it seems to be a general issue not related to any special scenario we are in currently.

@krishna2320 actually not related to meetings - the contact shown on the phone as external



I experienced the same thing.  Follow this process to fix it:


  • Exit the Microsoft Teams desktop client
  • Right click on the Teams icon in your system tray
  • Click Quit
  • Launch File Explorer
  • Browse to: %appdata%\Microsoft\Teams
  • Delete all files and folders in said directory
  • Restart Microsoft Teams
  • Restart the Computer (last resort but I would try just step 7, it may be sufficient) 


@Jaisson  Hi i followed your process i did remove files and folder from %appdata%\Microsoft\Teams

and it worked for the use.

Now after a month user is contacing me with the same issue.


So it work as workaround but i need a better solution.Thanks

So let me share my solution to this problem. I had this same error with one of my internal organization contact showing as external. Digging deep I found we had a contact created for that user pointing to his external private email (also Teams enabled).


External contact email attribute was:


Checking AD attribute for that internal user showed attribute: targetAddress: (basicly pointing to that contact address)


Changing targetAddress attribute to: resolved our issue.


Somehow our internal user get linked with that contact address.


Hope that helps someone.

@Berglez  Hello, I Had a similar issue in sharing and permissions for a shared calendar and I was pretty sure it may have something to do with your issue. Let me know if they relate!


Anyway, the resolution ended up being the licensed user was a shared mailbox (though was still signed into the account via Outlook as a regular account).

After switching the shared mailbox back to a user mailbox, the issue was resolved. Hopefully this happens to be your case!


@DJayce this resolved the issue for us.