Microsoft Teams Rooms, Teams phones and panels: ready for the EWS shutdown?

Short answer: Teams Rooms on Android, Teams phones and panels are ready from the device builds Microsoft lists in MC1486282. Update the devices. If you also use the older user-agent policy with EnforceAllowList, allow the Teams calendar user agent too, or room calendars stop loading.

✔ Has a Microsoft Graph version · vendor statements checked 26 Oct 2026

Deadline: Exchange Online blocks EWS by default from October 2026 (tenants are switched to EwsEnabled False, rollout to late April 2027) and turns it off for good on 1 April 2027, with no exceptions. Exchange Server on-premises is not affected.

Status

Ready from the builds in MC1486282. Under EwsApplicationAccessPolicy EnforceAllowList, add Teams CalendarSkypeSpaces/1.0a$*+ to EwsAllowList when you allow this app ID.

App ID in the EWS usage report:

What to do

  1. Update every Teams Rooms, phone and panel to at least the build listed in MC1486282 (Teams admin center → Teams devices).
  2. While older devices remain, keep cc15fd57-2c6c-4117-a88c-83b1d56b4bbe on the allow list.
  3. Check Get-OrganizationConfig | fl EwsApplicationAccessPolicy,EwsAllowList: with EnforceAllowList, a request must pass both lists.

More than one app? Run the free read-only script: it names every app still calling EWS in your tenant.

Allow-list it safely

Setting EwsAllowedAppIDs replaces the whole list, so adding one ID on its own removes every other app. Read the current list first, then write the merged list:

Get-OrganizationConfig -RetrieveEwsOperationAccessPolicy | Format-List EwsEnabled,EwsAllowedAppIDs
Set-OrganizationConfig -EwsEnabled $true -EwsAllowedAppIDs "<current IDs>,<new ID>"

Changes to the list take up to 24 hours. A blocked call returns HTTP 403 with the header X-EWS-Policy-Reason. The free script prints the merged command for every app in use (it never runs it).

Sources

MSP or IT partner? The M365 Readiness Pack runs this EWS check, the SMTP AUTH check and SPF/DKIM/DMARC for every domain once per client tenant, and writes a client-ready report with your logo, next steps and an email to send the client. Read-only, works with GDAP.

See the pack (from $49)
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