Some users may be unable to access or use Microsoft Teams

A post-incident report has been published.

A post-incident report has been published.

Title: Some users may be unable to access or use Microsoft Teams User impact: Users may have been unable to access or use Microsoft Teams. More Info: Impact included but may have not been limited to, audio and video calls, joining or initiating calls, and other calling-related functionality. Final status: Our review confirmed our automated recovery systems rerouted traffic to healthy infrastructure and the service has recovered to healthy levels. Scope of impact: Impact was specific to some users whose connection requests were routed through Germany, the United Kingdom and the United States who were unable to access or use Microsoft Teams. Preliminary root cause: We identified an issue affecting a subset of connection-processing workflows within Microsoft Teams infrastructure. The affected workflows recovered and impact reports subsequently declined. We're continuing to investigate what initially led to impact and will provide more information in our Post-Incident Report. Final status: Impact reports have subsided and our review of service health indicates that the service has recovered to expected levels. We are continuing to monitor telemetry closely to verify service stability and sustained recovery. Scope of impact: Impact was specific to some users whose connection requests are routed through Germany, United Kingdom and the United States who were unable to access or use Microsoft Teams. Start time: Monday, September 21, 2026, at 1:00 PM UTC End time: Monday, September 21, 2026, at 1:49 PM UTC Preliminary root cause: We identified an issue affecting a subset of connection-processing workflows within Microsoft Teams infrastructure. The affected workflows recovered and impact reports subsequently declined. We're continuing to investigate what initially led to impact and will provide more information in our Post-Incident Report. Next steps: - We’re evaluating our core service configurations to prevent the recurrence of similar impact in the future. In addition, we're further reviewing our monitoring systems to ensure we identify and are expediently alerted to these types of scenarios. We'll provide a preliminary Post-Incident Report within two business days and a final Post-Incident Report within five business days.

User impact reports are decreasing, however, we continue to investigate and validate whether this trend reflects sustained recovery. We're continuing to narrow our investigation to the infrastructure component responsible for processing affected connection requests and are correlating diagnostic telemetry across impacted regions. This quick update is designed to give the latest information on this issue. Next update by: Monday, September 21, 2026, at 3:30 PM UTC

Title: Some users may be unable to access or use Microsoft Teams User impact: Users may be unable to access or use Microsoft Teams. More Info: Impact includes, but may not be limited to, audio and video calls, joining or initiating calls, and other calling-related functionality. Current status: We're analyzing a portion of the infrastructure responsible for processing connection requests. In parallel, we're reviewing diagnostic data to determine the source of impact and identify a remediation plan. Scope of impact: Impact is specific to some users whose connection requests are routed through Germany, United Kingdom and the United States who are unable to access or use Microsoft Teams. Next update by: Monday, September 21, 2026, at 3:30 PM UTC

Title: Some users may be unable to access or use Microsoft Teams User impact: Users may be unable to access or use Microsoft Teams. Current status: We're reviewing service monitoring telemetry and system logs to isolate the root cause, in order to develop a remediation plan. Scope of impact: Impact is specific to some users in Germany, United Kingdom and the United States who are unable to access or use Microsoft Teams. Next update by: Monday, September 21, 2026, at 3:30 PM UTC

Title: Some users may be unable to access or use Microsoft Teams User impact: Users may be unable to access or use Microsoft Teams. Current status: We're reviewing service monitoring telemetry and system logs to isolate the root cause, in order to develop a remediation plan. Scope of impact: Impact is specific to some users in Germany, United Kingdom and the United States who are unable to access or use Microsoft Teams. Next update by: Monday, September 21, 2026, at 3:30 PM UTC