Update Calendar Interop authentication with OAuth 2.0 to continue Microsoft 365 interop

Quick launch summary 

We’re enabling OAuth 2.0 authentication support for Google Calendar Interop with Microsoft Exchange Online (Microsoft 365). Calendar Interop is a feature that lets you sync events and availability between Google Calendar and Exchange Online.

Currently, interoperability is available via Basic Authentication. Microsoft plans to stop supporting the use of Basic Authentication to access Exchange Online on October 13, 2020. This only impacts Microsoft Exchange Online (Microsoft 365), not on-premise Exchange implementations. If you use Exchange Online, you should update your authentication to use OAuth 2.0 by October 13 to ensure interoperability is not disrupted.

Getting started 

  • Admins: If you're currently using Basic Authentication, you must set up OAuth 2.0. You will not be transitioned automatically. You can set it up at Admin console > Apps > G Suite > Settings for Calendar > Calendar Interop Management. Use our Help Center to learn more about how to set up Calendar interop
  • End users: No change in end user functionality. 

Calendar OAuth 2.0 setup in the Admin console 

Rollout pace 


  • Available to all G Suite customers