Microsoft has confirmed that a multi-day outage affecting several Microsoft 365 services, which began on 31 August 2026, has now been fully resolved.

• What it was: A fault in a core authentication configuration disrupted sign-in and access across multiple Microsoft 365 services.
• Who was affected: Users of Microsoft Teams, Exchange Online, SharePoint Online, OneDrive for Business, Microsoft Purview, Microsoft 365 Copilot and Microsoft Defender XDR experienced intermittent failures and authentication errors.
• What the risk was: Email delivery delays, failed logins and interrupted collaboration tools, with some organisations affected for several days while Microsoft rolled out fixes in stages.
• What to check now: Confirm mail flow, Teams access and file sync are behaving normally. If you raised a ticket during the outage, the Microsoft 365 admin centre incident references are EX1464935 and MO1465074.

Microsoft reports service availability is now stable. If you are still seeing issues on any Microsoft 365 service, we recommend logging a ticket with your IT provider so it can be checked against the admin centre incident record.