Microsoft has just announced retirement dates for two of its online services made for businesses and government customers. They are the Azure ACS (Access Control Services) for SharePoint Online authentication, along with the SharePoint Add-In extensibility model.
In separate blog posts, Microsoft announced that both Azure ACS and SharePoint Add-Ins will stop working for new tenants on November 1, 2024. Both of those services will stop working for existing tenants and will be retired completely on April 2, 2026.
For Azure ACS customers, Microsoft states that their authentication needs in Microsoft 365 "will be better served by modern auth offered via Microsoft Entra ID." Microsoft first announced back in July that its Azure Active Directory (Azure AD) service would be renamed as Microsoft Entra ID. The blog post added:
If you are using custom developed applications or are using SharePoint provider hosted Add-Ins, we recommend switching those applications to use Microsoft Entra ID for authorization and authentication needs.
In addition to the shut down and retirement dates for SharePoint Add-ins, Microsoft also announced that adding, updating, and acquiring SharePoint Add-Ins on its online store will be closing down even sooner. It stated:
As of March 1st, 2024 Microsoft will not accept new SharePoint Add-Ins for listing in the public marketplace, from July 1st, 2024 SharePoint Add-Ins cannot be acquired anymore from the public marketplace. Using a tenant app catalog will stay supported and enables 3rd parties to offer their SharePoint Add-Ins until April 2nd, 2026.
Microsoft also recommends that customers who have used custom-developed SharePoint add-ins to begin migrating those add-ins to SharePoint Framework based solutions. It added that any SharePoint Add-Ins that were accessed from a public marketplace or from a third party should ask those sources for an update that will not need the SharePoint Add-In extensibility model. That option will expire on the same date that the SharePoint Add-Ins themselves will close down on April 2nd, 2026.