EWS retirement dates in Exchange Online

Checked 22 October 2026 against Microsoft's message center notices MC1447678 and MC1485116 and two Exchange Team blog posts of 21 October 2026.

DateWhat happens
1 October 2026Exchange Web Services in Exchange Online begins retirement.
8 to 9 October 2026Microsoft created and filled an allow list for Worldwide tenants that had EWSEnabled set to True and no list of their own on 3 October 2026, from the EWS activity of the previous 60 days. Microsoft warns that infrequently used apps may not have been identified. A tenant with EWSEnabled not set got no list; Microsoft says those tenants have EWS disabled in its phased retirement.
10 October 2026For affected Worldwide tenants, turning EWS on is no longer enough: an app needs to be on the tenant's EWS allow list, EWSAllowedAppIDs. Microsoft says apps not on the list may lose access to EWS.
From 21 October 2026Microsoft has started turning EWS off in Worldwide tenants that had neither EWSEnabled nor an allow list set. Each tenant first gets a 7-day warning in the Message Center, then Microsoft fills its allow list from the last 60 days of use and sets EWSEnabled to False. A tenant admin can turn EWS back on (see below); Microsoft support cannot do it for you.
1 April 2027Full retirement of EWS in Exchange Online begins.
Early October 2026 to early July 2027Microsoft's rollout window for the allow-list requirement across Worldwide, GCC, GCC High and DoD. The dated milestones above are for Worldwide tenants only; Microsoft gives none for GCC, GCC High or DoD.

If an EWS app stopped working

Search your Message Center for "EWS will be disabled in your tenant in 7 days" or "EWS has been disabled in your tenant". If Microsoft turned EWS off, a tenant admin can turn it back on in one of two ways:

Either change usually works within an hour, and can take up to 4 hours. Microsoft has already put the apps it saw in the last 60 days on your allow list; to see it, run Get-OrganizationConfig -RetrieveEwsOperationAccessPolicy | Fl EwsAllowedAppIDs. An app it missed has to be added, and changes to the list take 24 hours. Turning EWS back on works only until April 2027.

What to do before 1 April 2027

Every app that still uses EWS needs two answers: is it on your allow list now, and when does its vendor move it to Microsoft Graph?

Start with the EWS usage report, which lists the application ID of each app that called EWS in your tenant. Then check your EWSAllowedAppIDs list against it. Our vendor board lists the Graph dates vendors have published so far, each linked to the vendor's notice.

Look up an application ID

The lookup is free. To check a whole report at once, the tenant plan reads the usage report in your browser and gives a plan per app: $49 per tenant, or $199 for ten tenants.

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