Microsoft Teams Phone: End-of-support devices require replacement to retain calendar functionality

[What and why]

As communicated in MC1229952 and MC1254555, Microsoft is retiring Exchange Web Services (EWS) in Exchange Online. Due to this retirement, legacy Teams Phone devices that have reached end of support will no longer be able to display calendar information starting in October 2026.

Because these devices are no longer supported, no application update is available to move them away from EWS and no automatic upgrade path exists; hardware replacement is required to maintain calendar functionality. Since hardware replacement requires procurement, provisioning, and user rollout, organizations should begin the replacement process immediately to reduce operational impact.

[Rollout schedule]

• Worldwide: Rollout will begin in early October 2026 and is expected to complete by late April 2027.

[Impact on your organization]

Who is affected

• Organizations using any of the affected end-of-support Microsoft Teams Phone devices listed below.

Platforms and services

• Microsoft Teams Phone
• Exchange Online
• Exchange Web Services (EWS)

What will happen

• The Calendar app will no longer be displayed on impacted devices signed in with a meeting account or personal account.
• Calendar data will no longer be available on impacted devices.
• No software update is available to restore calendar functionality on these end-of-support devices; hardware replacement is required.

Impacted device models

[Action required and recommendations]

• Review your Teams Phone inventory and identify any impacted device models.
• Develop a replacement plan for affected devices before EWS disablement begins.
• Replace impacted hardware with currently supported and certified Microsoft Teams Phone devices. Replacing affected devices helps maintain supported Teams Phone experiences, including calendar access, meeting participation workflows, security alignment, and service reliability.

[Learn more]

• Deprecation of Exchange Web Services in Exchange Online | Microsoft Learn
• Release notes for devices in Microsoft Teams - Microsoft Teams | Microsoft Learn
• Retirement of Exchange Web Services in Exchange Online | Microsoft Community Hub
• The way to control EWS usage in Exchange Online is changing | Microsoft Community Hub