Unable to switch to Teams-only mode


I tried to switch from Island mode to Teams-only mode. But the admin center is not accepting the setting. Why? 


2020-09-30 10_32_37-Teams upgrade - Microsoft Teams admin center – Opera.png


The screenshot shows one of my demo tenants. But I have the exact same issue with one of my prod. Tenants too.


15 Replies
best response confirmed by Robert K (Contributor)
Hi @Robert K

Could be an issue with the TAC. Try with Powershell

Let me know how you get on. Hope this answers your question

Best, Chris

@Christopher Hoard 


Thank you. This helped a lot.


I tried

Grant-CsTeamsUpgradePolicy -PolicyName UpgradeToTeams -Global

 and got

This organization cannot be upgraded to TeamsOnly at the tenant level because there is an on-premise deployment of Skype for  Business detected in 1 or more of it sip domains, xxxx.yyy. Users can be individually upgraded to TeamsOnly using either Move-CsUser (if the user has an on-premises Skype for Business account) or Grant-CsTeamsUpgradePolicy (if the user is homed in Skype for Business online).


Then I tried

$userlist = Get-CSOnlineUser
foreach($User in $userlist)
 Grant-CsTeamsUpgradePolicy -PolicyName UpgradeToTeams -Identity $User.SipAddress


And this worked for me. Case closed. ;)

@Robert K 

You need to make sure you donøt have any wildcard DNS records, as the Teams upgrade experience will try and do a DNS lookup for the SfB on-prem Autodiscover records.

If you can't remove the wildcard A or CNAME records, you will need to enter the Office 365 admin center and enable Skype For business services for your domain,s and get the DNS records for Skype for Business Online setup in DNS so the Teams upgrade experience can then determine that you are not using Skype for Business on-prem.

If you ask me, they should add a -Force switch to the PowerShell command ;)

@Michael MardahlAre you saying to remove the lyncdiscover and sip cnames? We have been using skype online only and the DNS entries look correct for our domain but we are using a wild card and are seeing this error. I don't want to remove the DNS entries if that isn't the fix. 

@kevinlause You don't need to remove the Wildcard. Just make sure, that the correct SIP-records are set, from the templates in the admin-panel in 365.


I had the same issue, where we couldn't switch to 'Teams Only':

- New tenant

- No prior SfB setup, hence no SIP-records in DNS.

- Wildcard on primary domain.


I added the SIP-records and I was then able to upgrade through the TAC.

Hey Michael,
where can i enable Skype For business services for our domain's?
We have a primary forward lookup zone where all Skype DNS Entries setting up correctly. While we were trying to switch coexistence mode to teams only, we get an error that there is an on-premise deployment of Skype for Business detected in 1 or more of it sip domains, *DOMAIN*. Our users do have a UPN with a different domain. Do i have to create a secondary zone and add the skype DNS entries as well?
Best regards Martin
Hey KawslabMSFT,
where can i find the Template in the 365 admin-portal?
Best regards
you set this on your external dns. and for the domain you are using..

Check domains in admin portal..from there you can see what records you need

Hey Adam,
thanks for response. I can see, that we have one domain with missing DNS Seetings on united-domains (cname + SRV), i think once we added the required entries, we will be be able to do the Teams only Upgrade.
Thanks and best regards

@Robert K From my past experience, it creates confusion when you enable Teams in Island mode, Adminstrators assumed that Users are migrated to Teams.


The user is not homed in Skype for business online and homed  at SFB Server on-premises. Check where users are and plan migration to Teams then change TeamsOnly Mode.

Amit kumar

In addition, you cannot assign TeamsOnly mode as the tenant-wide default if you have a Skype for Business on-premises deployment (which is detected by presence of a lyncdiscover DNS record that points to location other than Office 365.





does anyone know if the DNS check is performed against all domains that are added in the tenant? We have added a lot of domains in the tenant and use only a small fraction of the domains for Skype / Teams. The rest is used only sporadically in Exchange Online. Are these domains also queried and do we really need to set the DNS entries for all domains?


Thanks in advance.

Hi @Robert K,


From reading this thread it seems there are a few solutions to this but my issue turned out to be having multiple domains registered to my tenant. My default domain had the required DNS records (see attached) but the others didn't and that was preventing the switch, even though all individual users had already been switched to Teams Only via the TAC.


I deleted the non-default domains as we didn't use them anymore and that worked but I imagine adding the same DNS records to them would also have solved the problem if they were needed.


Hope that helps anyone else with the issue.lync and SIP DNS 2021 04 16.png

Hey , this thread is awesome and it looks like at the end of the day if the SfB DNS Entries aren't pointed to O365 services then it will fail.

In my case Cloudflare's DNS Caching was enabled for both the SIP and lyncdiscover entries. Once I disabled DNS Caching in Cloudflare, the Domains area in o365 Admin Portal had all checks and the TAC Coexistance mode was able to be changed.