Outage in Microsoft 365
SIP devices can't make or receive calls
Resolved Minor
October 21, 2026 - Started 6 days ago
- Lasted about 1 hour
Incident Report
Summary AI Generated
**Microsoft 365 – SIP Devices Unable to Make or Receive Calls** A Microsoft Teams incident lasting approximately 1.3 hours prevented users from making or receiving calls on SIP devices, which disconnected upon their next synchronization attempt and could not be logged back into. Teams web, desktop clients, and Teams Phone Devices were unaffected. Microsoft identified the root cause and was working on developing a fix.
Title: SIP devices can't make or receive calls
User impact: Users may be unable to make or receive call using SIP devices.
More info: Once a SIP device attempts to perform its next synchronization, the device will disconnect. Users will be unable to log back into those devices and therefore can't make or receive calls using those SIP devices.
Calling functionality using the Microsoft Teams web and desktop clients, or Teams Phone Devices are not impacted.
Current status: We’ve identified the underlying root cause and we are working on developing a fix.
Scope of impact: This issue could impact any SIP device.
Next update: Wednesday, October 21, 2026 at 11:00 PM UTC
Components affected
Microsoft TeamsTrusted by 1,000+ teams
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Latest Updates ( sorted recent to last )
6 days ago - at 10/21/2026 07:44PM
Title: SIP devices can't make or receive calls
User impact: Users may be unable to make or receive call using SIP devices.
More info: Once a SIP device attempts to perform its next synchronization, the device will disconnect. Users will be unable to log back into those devices and therefore can't make or receive calls using those SIP devices.
Calling functionality using the Microsoft Teams web and desktop clients, or Teams Phone Devices are not impacted.
Current status: We’ve identified the underlying root cause and we are working on developing a fix.
Scope of impact: This issue could impact any SIP device.
Next update: Wednesday, October 21, 2026 at 11:00 PM UTC
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