MS Teams External Chat not working

New Contributor



I have been chatting with external users (clients) of different domains from my organizational account. Suddenly, this has stopped working. Instead of an 'External' tag next to their name, Now I see the user as 'Unknown'. The more worrying this, I still get the messages from them, but I'm not able to reply to them.


Can someone help me with this. Thanks in advance!

5 Replies



Are you the only one in your organisation with this problem or are there more users with the same problem? If there is changes made by your administrator for Teams I suggest that you report this to Microsoft Support via the Office 365 admin portal.

It's actually everyone in my org; not able to chat with external users @Linus Cansby.

@nitishkanann23 Make sure that nothing been changed with the settings for external communications by admins:


Test in the web client


And if that doesn't work contact Microsoft Support.


We have a similar problem. We have this workaround for the problem : 


Click on the name above in the chat, write a message in that chat window. This should work. 




We have a MS case open for this problem but this workaround makes it less of a problem for us.


Do you have exchange on premise or/and used skype on premise?

Is teams only set to "teams only" ?

Any other people with suggestions?