SharePoint Remote Event Receivers: What Admins Need to Know

Published: 2 August 2026. Every Remote Event Receiver (RER) registered in SharePoint Online will stop working on July 1, 2027. Microsoft issued Message Center notification MC1411726 in late June 2026 announcing the retirement. RERs registered through Azure ACS (Access Control Services) already stopped functioning on April 2, 2026; the July 2027 deadline covers all remaining RERs registered through Microsoft Entra applications.

Source: Remote Event Receivers are retiring - Microsoft 365 Developer Blog | Message Center ID: MC1411726

What Remote Event Receivers Are

Remote Event Receivers are SOAP-based WCF service endpoints that SharePoint calls when specific events occur in a list or library: an item is added, updated, deleted, or a file is checked in. They were the primary extensibility mechanism for SharePoint Online custom solutions from around 2013 onward. Consultants, ISVs, and in-house development teams relied on them heavily to build event-driven automation.

RERs operate in two modes. Synchronous receivers fire before an operation completes and can cancel it, for example blocking a file upload that fails a metadata rule. Asynchronous receivers fire after the operation and trigger downstream steps such as sending notifications, writing to an audit log, or launching a Power Automate flow. The retirement affects both modes.

The replacement technologies are SharePoint webhooks for asynchronous scenarios and Microsoft Graph change notifications for broader Microsoft 365 event coverage. Neither replacement supports synchronous cancellation; any solution that used a synchronous RER to block or modify an operation in flight will require significant redesign, typically moving the validation logic to a client-side check or a Power Automate approval step instead.

The Retirement Timeline

What to Do Before the Deadline

For most SharePoint Online administrators the immediate priority is identifying exposure, not writing replacement code. That step belongs to the development teams and ISVs who built the solutions. Your job is to confirm whether you are affected and make sure the right people know the deadline.

1. Inventory SharePoint Add-Ins on your tenant. Open the SharePoint admin center, go to Active sites, and look for any sites with Add-In web apps. The App Catalog at your tenant root also lists apps deployed across the tenant. Any installed SharePoint Add-In from before 2021 is a candidate for RER usage.
2. Check whether the April ACS retirement already broke something. Automated processes that ran silently in SharePoint (custom approval emails, triggered uploads, cross-system data writes) may have stopped around April 2, 2026. If you have outstanding unexplained helpdesk tickets about automation that stopped working, this is a likely cause.
3. Contact ISVs for third-party products. Any vendor whose SharePoint product was built before 2022 and is still installed should be able to confirm whether they used RERs and whether a replacement version is available. Most reputable vendors have already shipped webhook-based releases.
4. Plan the migration to webhooks for in-house solutions. SharePoint webhooks use standard HTTPS endpoints rather than WCF services. They are asynchronous only, deliver a notification payload to a registered URL, and the receiving service then queries SharePoint for the changed data. The architecture is simpler to build and operate than RER-based WCF services.

For context on related SharePoint extensibility retirements happening in parallel, see the alerts on SharePoint Designer 2013 end of support and legacy authentication retirement in SharePoint Online. These three retirements together represent a broad sweep of the pre-2015 SharePoint extensibility surface area.