July 31st, 2021, is the day that Skype for Business Online (SfBO) officially retires. What does that mean for you and your users? It means just that, that SfBO will not be available in Microsoft 365 anymore, and Teams Only mode will be the only option for users homed in Microsoft 365. In this article, Stale Hansen explains the different transition options available, shows how to flip your tenant over to Teams Only mode yourself, and offers some best practices based on personal experience.