Published: 18 August 2026. As of April 2, 2026, every SharePoint Add-In in every Microsoft 365 tenant stopped working. The retirement applied without a grace period to all environments, including GCC, GCC High, and the US Department of Defense. Azure ACS (Access Control Services), which provided authentication for provider-hosted Add-Ins, retired on the same date.
Source: SharePoint Add-In Retirement in Microsoft 365 - Microsoft Learn
What the SharePoint Add-In Retirement Shut Down
SharePoint Add-Ins came in two forms, and both stopped functioning on the retirement date.
SharePoint-hosted Add-Ins ran inside an isolated app web within your tenant. They used JavaScript against the logged-in user's context and typically appeared as web parts or full-page views. After April 2, those app webs became inaccessible. Any page that hosted an Add-In web part now renders a broken or empty frame, and users can no longer reach the app web content.
Provider-hosted Add-Ins ran on an external server and called back into SharePoint using Azure ACS for authentication. With ACS gone, those apps can no longer authenticate against SharePoint APIs. The downstream effect depends on the app: some fail silently (automated processes that nobody noticed stopped), and some fail loudly (custom interfaces showing an authentication error to end users).
The retirement does not affect SharePoint Framework (SPFx) solutions, Microsoft Entra ID-based apps, or any integration using modern OAuth flows against Microsoft Graph. If your tenant's custom solutions already run on SPFx or Entra, they are unaffected.
| Date | Milestone |
|---|---|
| Nov 1, 2024 | Add-Ins stopped working for tenants created after this date. Marketplace acquisition also closed from July 2024. |
| April 2, 2026 | All Add-Ins and Azure ACS retired across all existing tenants, including government clouds. No extension granted, no grace period. |
| Now (Aug 2026) | Content stored in Add-In app webs is inaccessible but not automatically deleted. Data extraction requires PowerShell or Graph API. |
How to Check Whether Your Tenant Is Still Affected
Four months after the retirement, unresolved impact usually shows up in one of three ways: broken intranet pages with missing or erroring web parts, automated processes that silently stopped around April 2, and helpdesk tickets that were closed as "no fix found" because nobody connected them to the retirement.
To assess your tenant systematically:
- Check the SharePoint admin center. Open Active sites and look for sites with names or URLs containing "appcatalog" or "apps". These are remnants of Add-In app webs. The tenant app catalog (at your root domain under /sites/appcatalog or similar) lists every deployed Add-In. Before building a full inventory manually, see the guide on building a SharePoint site inventory for a structured starting point.
- Run the Microsoft 365 Assessment tool. Microsoft provides a free scanner that identifies SharePoint Add-In usage across your tenant and generates a Power BI report. It lists every installed Add-In, its source (marketplace or app catalog), and for provider-hosted Add-Ins, the Azure ACS principal details. This is the most thorough method for inventorying your exposure.
- Review automation gaps since April. Pull helpdesk tickets from late March through May 2026 and look for complaints about dashboards not updating, emails that stopped arriving, or data integrations that broke silently. These are candidate areas for ACS-based automation that is no longer running.
Migration Paths After the Retirement Date
The correct replacement depends on what the Add-In was actually doing.
For UI components and web parts, the replacement is SharePoint Framework (SPFx). SPFx web parts run in the page context without an isolated app web, use the same SharePoint APIs, and are deployed through the tenant app catalog the same way Add-Ins were. Most ISVs who sold Add-In-based products have either released SPFx versions or have gone out of support.
Provider-hosted integrations that called SharePoint from an external service need to move from ACS to Microsoft Entra ID application permissions, using OAuth 2.0 client credential or delegated flows. The development surface stays the same - SharePoint REST API or Microsoft Graph - and only the authentication mechanism changes.
If you are still running third-party products that relied on Add-Ins, contact those vendors first. Mainstream SharePoint tools migrated to SPFx or Entra well before the April 2026 deadline. Any product that has not shipped an update in the last 18 months is unlikely to have a supported replacement and should be evaluated for decommission.
Related retirements still ahead: the alert on SharePoint Remote Event Receivers retiring July 1, 2027 covers the next wave of legacy extensibility being shut down. RERs share much of the same pre-2015 architecture as Add-Ins and will require a similar remediation effort for affected tenants.
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