A widespread outage across Microsoft 365 knocked out Outlook, Teams, SharePoint Online and the Copilot AI assistant for users in several countries, and had not been fully resolved at the time of writing. India was also affected. Outage tracker Downdetector logged more than 800 problem reports from the country by 9 am IST today.
Microsoft down: How far has it spread?
Downdetector said the disruption reached 74 countries in roughly an hour. Global Outlook complaints peaked at nearly 140,000 around 18:00 GMT (11:30 pm IST) on Thursday, more than 2,000 times the normal level, according to the BBC's account of the tracker's data. The platform first picked up problems just after 16:15 GMT, or about 9:45 pm IST, and the outage was still running more than eight hours later.
By early Friday GMT, Downdetector put the number of affected users at above 28,000, down sharply from the peak.
Microsoft's own advisory (MO1550821) says customers may be unable to connect to Exchange Online, Teams, SharePoint Online, Microsoft 365 Copilot and Microsoft Defender XDR. Reports on Downdetector also named Azure, OneDrive and the Microsoft Store.
What Microsoft says caused it
The company first blamed 'elevated load across multiple regions'. It later revised that explanation. According to BleepingComputer, Microsoft said the strain came not from higher traffic but from a number of servers becoming unexpectedly unavailable, which overloaded the remaining infrastructure.
Microsoft later said a core process on the affected servers was being overwhelmed, causing a loss of capacity. It said it had paused all deployments, redistributed traffic across its global infrastructure and begun restarting servers. It also said it was considering whether reverting a small number of recent configuration changes could speed up recovery.
Progress has been uneven. Microsoft reported limited recovery after returning some servers to service and shifting traffic to alternate routes. It then said its latest changes were 'not taking as expected' and that it was testing other methods to bring users back without overloading its systems. It also warned that services that have restarted can become unresponsive again once traffic returns, and that recovery will be gradual as applications reconnect.
Microsoft has not said whether the outage is linked to a separate Teams disruption earlier on Thursday. That incident, tracked as TM1550488, hit users in North and South America for about an hour, from 9:45 am to 10:53 am ET. Microsoft attributed it to resource contention and says it has been resolved.
Not a cyberattack, says Australia
Australia's Home Affairs and Cybersecurity Minister Tony Burke said Microsoft officials in the country told him they do not believe they are dealing with a cyber event. He said they described it as similar to the 2024 CrowdStrike incident, in which a faulty update froze Windows computers worldwide. Burke said the impact in Australia was largely on email systems.
Knock-on effects
The outage spread beyond Microsoft's own products. OpenAI said it was investigating an issue affecting its connections to Microsoft services, which left some tools not working as expected. Anthropic said it had identified an issue affecting its links to Microsoft 365 services.
Reports indicate that personal Microsoft accounts were largely unaffected, while many work and enterprise accounts could not reach Outlook, Teams and other services.
This is the second major Microsoft 365 disruption this year. A similar outage hit Outlook, Teams and other services in January.
