Your Skype for Business client will no longer allow you to authenticate. You may see one of the following error messages:

• Can’t sign in to Skype for Business 
• The user name, password, or domain appears to be incorrect.
• You’ve tried to sign in too many times with an incorrect email address or password, or someone else is trying to sign in to this account.

  You should dismiss these messages and use Teams Calls for all future communications that you would have previously conducted in Skype for Business.

  If you wish, you can disable Skype for Business in your list of startup apps to prevent it from launching automatically.

After the conversion begins, it may take up to an hour for the dial pad to appear in the Microsoft Teams application. Dial pads are not available in browser versions of Teams. You may need to close and relaunch the app or restart your computer for it to appear.

You can use Microsoft Teams to communicate with people who are still using Skype for Business; however, some features may not work across platforms. These are temporary issues until all accounts have been moved to Teams Calls. Interoperability limitations include

• You can’t make or receive video calls with Skype for Business users.
• You can’t share your screen with Skype for Business users or see their screens.
• You can chat with text only, but you can’t use emojis, @mentions, or rich formatting.
• You can’t search for Skype for Business users by phone number.

All of your Skype for Business contacts, both internal and external, will be available from the Calls app in Microsoft Teams.

Call forwarding settings are not automatically transferred to Teams Calls. To recreate your settings in Teams, see Call forwarding, call groups, and simultaneous ring in Teams.

• If you had enabled conversation history in Skype for Business, your IM conversations are stored in the Conversation History folder in Exchange, and they will remain there. In Microsoft Teams, all chats are persistent within the app. You can delete individual chat messages, but others in the conversation will see “This message has been deleted.”
• If you have logs of audio or video calls made in Skype for Business, they will remain in the Conversation History folder in Exchange. If you recorded any audio or video calls, those were stored on the hard drive of your computer; the default path should be:
  

  C:\Users\username\Videos\Lync Recordings
  

  In Microsoft Teams, you’ll see a log of all types of calls (incoming, outgoing, or missed) on the Calls app.