A Microsoft 365 outage that began on the afternoon of November 12, 2026, ran for more than 12 hours. It disrupted banks, governments and courts across 74 countries and territories.
Some businesses fell back on fax machines to confirm trades.
How the failure spread
The trouble started at approximately 16:17 UTC. Exchange Online, the backbone of Microsoft’s corporate email service, was the first system to falter.
Within about one hour, connectivity failures had spread worldwide and reached a lineup of tools that most office workers touch before their first coffee.
Outlook, Teams, Copilot, SharePoint Online and OneDrive all experienced issues. For a large share of the working world, that covers email, meetings, chat, shared documents, cloud storage and Microsoft’s AI assistant at once.
Downdetector logged a peak of more than 130,000 Outlook-related complaints in the US alone. Reports also arrived from users in 74 countries and territories.
Microsoft’s engineers spent more than 12 hours on recovery. Their efforts included rerouting traffic and restarting servers.
Many services kept failing intermittently, and full restoration was still in progress as of November 13, with Microsoft describing service health as variable.
Not a hack, just a load problem
Microsoft has ruled out a cyberattack as the cause. The company instead pointed to unexpected server unavailability, which pushed extra load onto the infrastructure that was still running.
The effects went well beyond missed meetings. Government operations slowed in several countries, with delays reported in visa processing and court operations.
Banks and airlines also faced disruptions. AI companies OpenAI and Anthropic reported operational problems linked to the outage as well.
Second major outage of the year
This is the second major Microsoft 365 outage of 2026, following an earlier incident this year.
Reports put Microsoft 365 at approximately 430 to 450 million users, which means a single failure point can affect a population larger than most countries.
What this means
For enterprise customers, the outage is an unplanned stress test of their contingency plans. Firms that had to confirm trades by fax now have a concrete reason to revisit what their backup options really look like when email, chat and file storage fail together.
The bundling that makes Microsoft 365 attractive is also its weak point. One subscription covering email, meetings, documents and AI is convenient until a single disruption takes all of them offline at the same time.
Governments face the sharpest version of the question. The outage showed that visa processing and court operations in several countries can hinge on a commercial cloud service staying online.