Want to be rid of Skype for Business and Teams cohabitation?
You want to receive directly Skype calls on Teams, but option ‘Teams Only’ does not appear in teams upgrade …
If you are that case where option ‘Teams only’ does not appear, switch to your friend PowerShell

- Download powershell module for SkypeBusiness Online here
- Open powershell and execute:
Import-Module SkypeOnlineConnector
$mySession = New-CsOnlineSession
Import-PSSession $mySession
Grant-CsTeamsUpgradePolicy -PolicyName UpgradeToTeams -Global
After that, you receive the following message “*All* users in this tenant will become full Teams-only users, except for any users that have an explicit policy assignment of TeamsUpgradePolicy. Teams-only users cannot use Skype for Business clients, except to join Skype for Business meetings. For details, see http://aka.ms/UpgradeToTeams.
Then, you can receive direct external calls from Skype and SkypeForBusiness to your single Teams program. That’s it !