LONDON, Nov 13 – Microsoft experienced a widespread service outage on Thursday and Friday, disrupting access to Outlook, Teams, SharePoint, Copilot and other Microsoft 365 services across multiple regions.
The disruption began shortly before 1 p.m. Eastern Time on Thursday and continued into Friday, affecting users across Asia-Pacific and Europe during key business hours. Services connected to Outlook features, including Calendar, also experienced problems.
In an update issued shortly before 7:30 a.m. in London on Friday, Microsoft said some users remained unable to connect to multiple Microsoft 365 services through both web and desktop applications.
The company did not provide a timeline for full restoration but reported improvements in server stability after deploying a patch to parts of its infrastructure.
“We are seeing positive results for server stability,” Microsoft said, adding that it was continuing to investigate the incident.
“As of now, we are not aware of any malicious activity that is causing this incident. We will continue to treat this incident with urgency and priority until full resolution,” the company said. Microsoft also pledged to publish a detailed report after the disruption had been resolved.
The company was deploying additional computing capacity through virtual machines, which allow software-based servers to operate on physical hardware, as part of efforts to stabilise affected services.
Businesses and governments assess operational impact
The outage disrupted business activities across several industries, with organisations in Asia-Pacific and Europe monitoring its effects and adjusting operations.
Swiss luxury goods group Richemont experienced a slight delay to its earnings announcement on Friday. US electric truck manufacturer Workhorse Group also postponed the release of its third-quarter results, originally scheduled for November 12, to November 16, citing business disruptions caused by the Microsoft outage.
Air India said it had temporarily rerouted its emails to maintain the receipt of customer messages, while confirming that its flight operations were unaffected.
Australian Home Affairs and Cyber Security Minister Tony Burke said Microsoft believed the incident could resemble the 2024 global IT disruption linked to a faulty software update from cybersecurity company CrowdStrike.
That incident affected airlines, banks and other organisations worldwide after a defective CrowdStrike update disrupted systems running Microsoft Windows.
The latest outage also highlights the operational dependence of businesses on cloud-based productivity and communications platforms. Microsoft reported in 2025 that Copilot, its collection of artificial intelligence assistants and tools, had more than 100 million monthly active users.
Microsoft identifies server availability problems
Microsoft initially attributed the connectivity issues to elevated infrastructure loads across multiple regions. It later identified the underlying problem as the unexpected unavailability of several servers, which placed additional strain on the remaining infrastructure.
The company also found that some servers were failing automated health checks, preventing them from operating as expected.
Microsoft said it had taken steps to limit the number of additional servers affected while working to restore the unavailable infrastructure.
By 4 p.m. Eastern Time on Thursday, the company had validated an alternative service health-check method that brought some affected servers back online. It said it was expanding the approach across the wider infrastructure and preparing automated recovery systems to identify and restart unresponsive servers.
The outage coincided with reports of service disruptions involving Amazon Web Services and Google on the same day. Amazon said its services were operating normally and described reports linking its infrastructure to the incident as inaccurate, directing users to its service health dashboard for updates.
Microsoft has yet to publish its full incident report, leaving the precise technical cause and the total number of affected users and organisations unclear.
