S4B on-premises to Teams

Occasional Contributor

Yes sorry another question about upgrading S4B to Teams :)

I know there is a lot of content on docs.technet and blog post about upgrading but I have a question I could not find.


Is it possible to do a cutover Teams migration without creating a hybrid S4B environment?

I know that in a cutover migration contact data and meetings data will not be migrated but if the organization accepts this can we not just flip the switch?

With this I mean is it supported/possible/does it work if we;
- do not create hybrid S4B

- set Teams mode to Teams Only

- decomission S4B on-premises


Or is a hybrid S4B always a requirement?


reference cutover




1 Reply

Hi @fatshark_2k , I don't know if it is a support way. But if you want to do a cut over migration and you have configured Azure AD sync in the past with a Lync/SfB OnPrem installation, all related attributes are synced to Azure AD. Therefor a cutover is only possible if you disable all OnPrem SfB user for Skype for Business. That way the related SfB attributes will be cleared OnPrem and will be synchronised to Office 365. Afterwards the Office 365 Service will "redeploy" the user accounts with SfB Online aka Teams services. I would suggest testing it in advance.

With the Teams Powershell and a connection to SfB Online you can check the deployment state of a certain user by Get-CsOnlineUser <SIP Address>. 

Stale Hansen wrote a great blog article about OnPrem attributes clean-up in another context: My post-migration from Skype to Teams toolbox – msunified.net