Some users in the United Kingdom may have been unable to access multiple Microsoft 365 services

Title: Some users in the United Kingdom may have been unable to access multiple Microsoft 365 services User impact: Users in the United Kingdom may have been unable to access multiple Microsoft 365 services. More info: Impacted services may have included, but weren't limited to: - Microsoft Teams - Outlook Final status: While implementing traffic optimization actions within the affected environment, we observed service recovery and subsequently confirmed that users could successfully access impacted services. We're continuing to analyze service telemetry, authentication logs, and recent service changes to isolate the underlying cause and help prevent similar impact in the future. Scope of impact: Impact was specific to some users in the United Kingdom attempting to access multiple Microsoft 365 services. Start time: Thursday, September 10, 2026, at 8:10 AM UTC End time: Thursday, September 10, 2026, at 1:39 PM UTC Root cause: Some users may have been unable to access Microsoft 365 services due to facing authentication errors. Next steps: - We're reviewing service telemetry, authentication logs and recent service changes to isolate the root cause and prevent similar impact from happening again. This is the final update for the event.

Title: Some users in the United Kingdom may be unable to access multiple Microsoft 365 services User impact: Users in the United Kingdom may be unable to access multiple Microsoft 365 services. More info: Impacted services may include, but aren't limited to: - Microsoft Teams - Outlook Current status: We've identified that a recent authentication component change may be causing users to be unable to access Microsoft 365 services. We're redirecting affected traffic to alternate infrastructure to validate the root cause and provide mitigation. Scope of impact: Impact is specific to some users in the United Kingdom attempting to access multiple Microsoft 365 services. Next update by: Thursday, September 10, 2026, at 3:30 PM UTC

Title: Some users in the United Kingdom may be unable to access multiple Microsoft 365 services User impact: Users in the United Kingdom may be unable to access multiple Microsoft 365 services. More info: Impacted services may include, but aren't limited to: - Microsoft Teams - Outlook Current status: We're proceeding with reviewing service monitoring telemetry to isolate the root cause and develop a remediation plan. Scope of impact: Impact is specific to some users in the United Kingdom attempting to access multiple Microsoft 365 services. Next update by: Thursday, September 10, 2026, at 1:30 PM UTC