By combining instant messaging, calling, and video into one application, Skype for Business Online established new possibilities for business communications. Since its introduction, Skype for Business Online has been a valuable tool for millions of people around the world. Why is Skype for Business Online retiring? As Skype for Business Online is retired, we want to ensure customers have the information and resources they need to plan and execute a successful upgrade to Teams. In July 2019, we announced Skype for Business Online will be retired on July 31, 2021, giving our customers two years to plan their upgrades to Microsoft Teams, the core app for communication and collaboration in Microsoft 365.