Upgrade from Skype for Business on-premises to Teams

Upgrade journey diagram, emphasizing Deployment and Implementation

This article is part of Deployment and Implementation stage of your upgrade journey. Before proceeding, confirm that you've completed the following activities:

If you've deployed Skype for Business Server or Microsoft Lync on-premises and your organization wants to upgrade to Teams, follow the guidance in this article. You need to set up hybrid connectivity with your Microsoft 365 or Office 365 organization, and determine coexistence requirements if you are moving your users to Teams in phases.


Skype for Business Online will be retired on July 31, 2021, after which it will no longer be accessible or supported. To maximize benefit realization and ensure your organization has proper time to implement your upgrade, we encourage you to begin your journey to Microsoft Teams today. Remember that a successful upgrade aligns technical and user readiness, so be sure to leverage the guidance herein as you navigate your journey to Microsoft Teams.

Step 1: Configure hybrid connectivity

The key prerequisite for upgrading your on-premises users to Teams is to configure hybrid connectivity for your Skype for Business Server on-premises deployment.

Start by reading Plan hybrid connectivity and then follow the tasks outlined in Configure hybrid connectivity.

Step 2: Set transitional coexistence mode (optional)

Coexistence and interoperability between Skype for Business and Teams clients and users are defined by Teams Upgrade modes. By default, organizations are in Islands mode, which allows users to use both Teams and Skype for Business clients side by side.

For an organization moving to Teams, TeamsOnly mode is the final destination for each user--though not all users need to be assigned TeamsOnly (or any other mode) at the same time.

Prior to users reaching TeamsOnly mode, organizations can optionally use any of the Skype for Business coexistence modes to ensure predictable communication between users who are in TeamsOnly mode and users who aren't yet. The purpose of the Skype for Business coexistence modes (SfBOnly, SfBWithTeamsCollab, SfBWithTeamsCollabAndMeetings) is to provide a simple, predictable experience for end users as organizations transition from Skype for Business to Teams.

When a user is in any of the Skype for Business modes, all incoming chats and calls are routed to the user's Skype for Business client. To avoid end-user confusion and ensure proper routing, calling and chat functionality in the Teams client is disabled when a user is in any of the Skype for Business modes. Similarly, meeting scheduling in Teams is explicitly disabled when users are in the SfBOnly or SfBWithTeamsCollab modes, and explicitly enabled when a user is in the SfBWithTeamsCollabAndMeetings mode.

Depending on your requirements, you can assign the appropriate coexistence mode based on the upgrade path that your organization has chosen. For more information, see Migration and interoperability guidance for organizations using Teams together with Skype for Business and Setting your coexistence and upgrade settings.

Step 3: Move users from Skype for Business on-premises to Teams Only

Ultimately, you'll want to move your users to TeamsOnly mode. This might involve one or two steps depending on your current on-premises environment.

For more information, see Move users between on-premises and the cloud and Move users from on-premises to Teams.

Phone System and Teams upgrade

If you are transitioning your Skype for Business deployment to Phone System with Calling Plans, Microsoft will be your public switched telephone network (PSTN) provider. Assuming that you've completed the phone number porting--upgrading your users to Teams will automatically transition inbound PSTN calling to Teams.

If you are transitioning your Skype for Business deployment to Phone System but are not using Calling Plans, you need to transition your enterprise voice deployment to Microsoft Phone System Direct Routing. For more information, see Phone System Direct Routing.