Microsoft apologises for outage that hit Outlook and Teams for 24 hours
A failed network upgrade disrupted Microsoft 365 services including Outlook and Teams for almost a day, with the NHS among those affected.
Key takeaways
- A network capacity upgrade caused an outage affecting Microsoft 365, Outlook, Teams and OneDrive for almost 24 hours.
- Microsoft apologised and said the issue was not related to cyber attacks or AI.
- The NHS in the UK reportedly lost access to email and Teams during the outage.
- Microsoft will publish a full post-incident report once its review is complete.
What happened
Microsoft has apologised for a major outage that disrupted Outlook, Teams, OneDrive and other Microsoft 365 services for almost 24 hours. According to Windows Central, the company explained the cause in a post on X on 13 November 2026 and said service has largely been restored.
The company blamed a problem during an earlier network capacity upgrade that surfaced after a recent network change. Microsoft says the underlying issue has been addressed.
Why recovery took so long
Microsoft said it restored services gradually, validating stability at each stage. It acknowledged this took longer but said the approach helped ensure a stable restoration.
The company also stressed the incident was technical and not related to cyber attacks or AI. It said a full post-incident report will follow once its review is complete.
Who was affected
Businesses around the world lost access to email and collaboration tools for much of the day. Windows Central reports that the National Health Service in the United Kingdom could not reach email or Teams, delaying some health services.
Xbox services were also reportedly affected, including Xbox Cloud Gaming, cloud saves and account sign-ins, though these reports are not confirmed by Microsoft.
What comes next
Microsoft says it will publish a full post-incident report in the coming days and weeks. Organisations that rely on Microsoft 365 may want to watch for that report to understand the failure and any changes Microsoft makes as a result.
Sources
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