Microsoft 365 Suffers Ten-Hour Outage Affecting Millions Worldwide

Major Cloud Failure Disrupts Global Business Operations

Microsoft confirmed it resolved a widespread outage affecting its cloud services on January 23, 2026, after nearly ten hours of disruption that left enterprise customers unable to access email, files, and collaboration tools during peak business hours.

The outage began around 2:30 p.m. Eastern Time on January 22 and impacted multiple services including Outlook, Teams, Microsoft Defender, Microsoft Purview, and the Microsoft 365 admin centre. At its peak, more than 15,000 reports flooded incident-tracking site Downdetector, with users reporting inability to send or receive messages and encountering server error messages.

Root Cause Identified

Microsoft attributed the disruption to infrastructure problems in North America. According to the company, elevated service load combined with temporary capacity constraints during maintenance resulted in the impact. Reports indicate that too many servers hosted in North America were shut down during routine maintenance, causing excessive load that affected services globally.

The company worked through the night to restore services, posting updates indicating it was rebalancing traffic across all affected infrastructure to stabilise the environment. At approximately 1:30 a.m. Eastern Time on January 23, Microsoft announced that impact had been resolved, though some users continued to report lingering issues.

Second Major Outage in 24 Hours

The disruption marked the second major Microsoft outage within 24 hours, raising questions about the company's infrastructure reliability. On January 21, Microsoft 365 and Teams suffered a brief outage that the company attributed to a third-party network issue.

While the January 22 outage primarily affected North America, users in the United Kingdom, Germany, France, Australia, India, Japan, and Brazil also reported problems.

Growing Pattern of Cloud Failures

Industry analysts warn that cloud outages are becoming more frequent as providers struggle to balance growing demand with aging infrastructure. The concentration of critical infrastructure creates cascading risks when failures occur, and experts predict this trend will continue as companies prioritise AI workloads over traditional services.