Microsoft 365 Outage Knocked Out Email and Teams for 25 Hours Across 74 Countries

Quick Facts

• The outage began at 16:17 UTC on November 12, 2026, and was fully restored at approximately 04:43 UTC on November 14, lasting more than 25 hours.
• Reports of problems with Outlook peaked at 138,058 on Downdetector, with users across 74 countries affected.
• Anderson Economic Group estimates the outage cost $7 billion in lost productivity globally.

A major infrastructure failure knocked Microsoft 365 services offline for more than 25 hours starting November 12, 2026, disrupting businesses, hospitals, law enforcement agencies, and government offices across the world. The outage is one of the longest in Microsoft's history and the second disruption to its services in 2026.

Microsoft confirmed full restoration of services at approximately 04:43 UTC on November 14, stating: "We have completed our efforts to address the underlying issue of the incident and restored service to the remaining impacted customers and regions."

What Failed and Why

The disruption began with Exchange Online mailboxes and spread to Teams, SharePoint, Microsoft 365 Copilot, and Defender XDR. Exchange Online servers began failing automated health checks, dropping out of service and pushing excess load onto remaining servers until those were overwhelmed as well.

Microsoft's initial recovery attempts failed. Servers brought back online collapsed again under returning traffic. Overnight, Microsoft began reversing a recent network configuration change it identified as the trigger.

The company said in a statement: "This was a technical issue not related to cyber or AI / agents. The incident was introduced by an issue during an earlier network capacity upgrade that surfaced following a recent network change." Microsoft has not yet published a final root cause analysis but said a full post-incident report is coming.

Scale of the Disruption

Within an hour of Microsoft's first status alert, reports on Downdetector surpassed 100,000. By the evening of November 12, 140,000 people across 74 countries had logged complaints covering Outlook, Teams, Microsoft 365, and Copilot. Reports peaked at 138,058 the following day.

Microsoft 365 serves more than 430 million users of its apps, and the company reported more than 450 million paid commercial subscriptions as of January 2026. Microsoft shares fell 1.7% before the bell on November 13.

Government and Public Sector Hit Hard

The NHS reported "serious" and "widespread" disruption across hundreds of hospitals, GP surgeries, and community health services in the United Kingdom. Some operations were cancelled. Electronic prescription systems reported problems, and Metropolitan Police officers said the outage affected their ability to process crime reports online.

In the United States, the House of Representatives confirmed it was impacted, and Baltimore County Government said staff could not send or receive email, though 911 services remained operational. Law enforcement agencies reported problems processing prisoners' bail payments.

In Japan, government services switched to paper documents. The Philippines' Supreme Court warned of delays to email-based transactions. Japanese lawmaker Masanao Ozaki said officials were monitoring Microsoft's response closely.

Financial Toll

Anderson Economic Group, a Michigan-based think tank, put the productivity loss at $7 billion. Mario De Cicco, VP of European financial institutions at Morningstar DBRS, estimated global insured losses between $300 million and $500 million. That figure sits below the $400 million to $1.5 billion financial toll from the 2024 CrowdStrike outage.

At least one bond repurchase in Europe was halted during the disruption. Some organizations reverted to fax machines to maintain basic communications.

What Comes Next

Microsoft has formally tracked the Exchange Online disruption under incident ID EX1550543 and the broader Microsoft 365 event under MO1550821 in its admin center. The company has committed to a post-incident report once its internal review is complete. For companies running critical workflows through Microsoft 365, the outage adds pressure to review redundancy plans and assess dependency on a single cloud provider.