A massive Microsoft outage disrupted businesses, governments and financial institutions worldwide for more than 24 hours, with economic losses potentially reaching billions of dollars.
Beginning November 12, the failure affected Outlook, Teams, Exchange Online and Copilot, interrupting communications across more than 70 countries. Microsoft confirmed full restoration on November 14.
The financial consequences could be substantial. Anderson Economic Group estimated up to $7 billion in lost productivity, while insurance ratings agency Morningstar DBRS projected $300 million–$500 million in insured losses. Both are preliminary estimates, not confirmed financial losses.
The disruption delayed corporate earnings announcements, affected airlines and government services, and forced some financial institutions to revert to fax communications.
Microsoft attributed the failure to a problem involving an earlier network-capacity upgrade and subsequent infrastructure changes, ruling out cyberattacks and AI involvement.
The incident reinforces earlier IMF warnings about systemic risks from concentrated cloud infrastructure and raises questions about the resilience of Big Tech's increasingly interconnected cloud-computing industry.