One network change, 74 countries: Microsoft's day-long 365 outage

Microsoft 365 services went down across at least 74 countries starting around 16:00 GMT on Thursday 12 November 2026, and nearly 24 hours later the company still could not say when everything would be back.

The outage knocked out Outlook, Teams and Copilot. More than 430 million people use those products worldwide. Within an hour, Downdetector logged over 100,000 reports. Courts, law enforcement, healthcare providers, schools, governments and businesses lost email and collaboration tools. Corporate earnings reports slipped.

Microsoft traced the failure to an issue that emerged during an earlier network capacity upgrade, triggered by a more recent network change. The company ruled out malicious cyber or AI activity. "There is no indication this is the result of malicious or cyber activity," Microsoft said.

Recovery was deliberately staged rather than a single large-scale restart. More than 12 hours in, Microsoft reported only "marginal success" at restoring its most widely used workplace services. By Friday afternoon it claimed "broad recovery," but warned it had no ETA for full recovery and that message delivery and processing were still catching up. "Service access can recover before mail flow fully normalizes," the company said.

The incident was not a cyberattack. That distinction matters less to the hospitals, courts and schools that lost service than the common thread: a single non-malicious fault at one company disrupted operations across dozens of countries simultaneously.

Experts called the event a "stark reminder" of how heavily businesses and vital services rely on a small group of big tech providers. The outage made it visible at scale.