Microsoft to Sunset Outlook REST API v2.0 in 2024

Office 365

Key takeaways:

  • Microsoft is deprecating the Outlook REST API v2.0 in 2024 due to feedback from customers and partners.
  • The transition aims to encourage developers to migrate to Microsoft Graph for improved security, reliability, and performance.
  • Microsoft has provided guidance to assist customers and developers in planning a successful migration to Microsoft Graph.

In a notable shift for developers, Microsoft has revealed its plan to retire the Outlook REST API v2.0 in 2024. This decision stems from feedback received from customers and partners. The Outlook REST API is undergoing this transition to make way for a smoother and more secure future with Microsoft Graph.

The Outlook REST API is a web-based API that allows developers to access and interact with Microsoft Outlook data and services. It enables developers to integrate Outlook functionality into their applications, such as calendar, email, and contacts. The Outlook REST API lets custom apps access data from Office 365,, and Exchange Server.

Microsoft originally unveiled its plans to kill off the Outlook REST API beta in November 2020. The company has considered it a legacy surface since 2020 and has been encouraging developers to switch to Microsoft Graph instead. However, Microsoft found that it would require changes to the legacy code, and customers were not ready to let go of the API completely. Consequently, the company decided to delay the deadline for deprecation until 2023.

“In January 2023 we announced the decision to delay the final decommissioning date for Outlook REST API v2.0 and corresponding beta endpoints. This was done as a response to signals and feedback received from our customers who required more time to achieve a successful migration to Microsoft Graph. At that time, we did not define a new decommissioning date,” Microsoft explained.

Outlook REST API v2.0 nearing end as Microsoft issues final warning

In a recent blog post, Microsoft announced that it will finally sunset the Outlook REST API v2.0 and beta endpoints on March 31, 2024. After this date, calls to the Outlook REST API will trigger an HTTP 404 error and a deprecation message. Microsoft confirmed that the upcoming change won’t impact all Outlook add-ins that use Outlook REST.

Microsoft has advised developers and customers to prepare for the transition from the Outlook REST API v2.0 to Microsoft Graph. “We understand that for some applications this change, even if anticipated, will require some amount of work to accommodate, but we are confident it will ensure better security, reliability, and performance for our customers,” Microsoft added.

Microsoft has also published detailed guidance to help customers plan a successful migration to Microsoft Graph. If you’re interested, we invite you to check out Microsoft’s official documentation for more details.