Communicate with an external Skype for Business user


In MS Teams, how do I communicate with a Skype for Business user not in my directory? Someone in another company? In Skype for Business, we just input their email address. Doing that in Teams under people, doesn't seem to ever result in anyone. I've already turned on globally the guest access feature of Teams.

62 Replies

This is how it works for me:

Contact an external Skype for Business user from within Teams without giving Guest Access.

Click the ‘New chat’ icon. 1.png


Type in the SIP address of the person to contact



Click ‘Search externally’.



Type your message and send.



To contact the person faster in the future, go to Chat > Recent, right click the person and ‘Add to favorite contacts’.



 Thats the only option I see.. Do I need to do something special ?





Make sure your tenancy has external contact search turned on. It can be found in the Skype & Teams Admin centre. It can take a couple of days for the function to become after activating. 


I've just tested using Daniel's description and I can see external users.  Still need to fully test the functionality that I can perform with them so the jury is still out. 

Not sure if this helps here, but I attended a session at Ignite that outlined the current status of Teams and Skype federation:




Seems to indicate that your geo will dictate the availability/current status of federation.


Hi Keith,


It works in my private Office 365 tenant, now we want to enable this in our corporate tenant, but we can't find the option in both tenants.


Could you maybe make a screenshot of the location of the setting within the Skype and Teams Admin Center.




Here is a screen-shot of the setting in the Teams/Skype admin centre

Aaah Cheers James, we were lookup for a setting called "external contact search" ;)

Thanks for the great tips guys. 


I keep getting this message when I try to connect to an external SFB SIP account. We have confirmed that the external organization has enabled the "external" connection access on their side as well. 




Am I missing something?




I have the exact same situation. So, I opened a support incident at O365. But after 2 hours checking my config and the config of the other Tenant - it seems they have no Idea why. We figured out that one single contact from the other Tenant we are able to chat,  see his presence, do phonecalls over federated sip. Strange Thing: That user has the same config as other users from the same tenant, where we cannot communicate with.


Just as an update - The other organization was (and still is) on SFB and haven't yet moved to MST. Guess SFB-MST don't like to talk to each other? 


In any case, I've ended up having to create an Inter-corporate group/channel and push all external users as guests. Not ideal by any count; but it gets the job done. For now.



I'm having the same issue here.  I created a new O365 tenant last week.  Everything works great with IM to external users in S4B, but not in teams.  In teams I search for people and some days I get the message about our orgs not being connected, and some days it just says no results.  I opened a support ticket with O365 support and they said the other domain has to whitelist my domain, which seems incorrect according to the documentation.  As long as I have external access enabled in the teams admin center, and no domains listed, all domains should work.  I'm trying to IM users.  I'm a former employee and want o chat with my former colleagues through teams :)  

Hi Oleg, 


I am trying to enable the option for our organization but unable to do so. 

I was trying to enable it via Services & add-ins > Microsoft Teams: Settings by user/license type - change to Guest and change it to On. But the Option ON is grayed out. 

Any idea what might be the issue?

This setting is moved to the Skype and teams admin center!
You reach this from the admin portal as well!



Kaushalya, you are referring to an old setting which was to enable guest access to Teams itself. But this topic is about communicating with external Skype for Business users via Teams. So i'm not sure what you want to achieve. As Adam mentioned the setting you refer to has been moved to Teams & Skype admin center. One can also enable communication with external Skype users in the same admin center. Read through the topic and check the screenshots.

I think he replied to your post a while ago we’re you described how to add guests to teams..
The old settings location was described there as well :)


Hi Adam, 


Thanks for the reply. In that case, the page shows can't upload any data. Any advise? 




Hmm! Try using a different browser!
This setting is for federation to other tenants! Might also be what you want but the settings for teams guests is under “guest access”

Hi Adam, 


Same issue in all browsers and a blank page opens while trying to open GUESS ACCESS option. Let me again go through it all again and check what am I doing wrong and let you guys know!

I think you are then better contacting Office 365 support.
Any News on this? We have the same issue?