Microsoft outage lasts more than 22 hours as issues reported in more than 70 countries

Microsoft apologises and says the failure was technical, not a cyber-attack

Routine automated checks took some Microsoft servers offline, and the machines left running were then overwhelmed by traffic. The result was a critical outage of Microsoft 365 services including Outlook that lasted more than 22 hours, prompting questions about how far vital services depend on a handful of major technology firms.

The repair stretched across nearly a full day as engineers restored services in stages, a sequence that highlighted how embedded Microsoft’s services are in modern society.

The scale of the user base helps explain the reach of the failure: around 430 million people globally use Microsoft 365. Issues were reported across more than 70 countries, and the trouble was not confined to businesses — organisations and public institutions around the world were affected as well.

The fallout was wide-ranging. It knocked out email systems for the US House of Representatives and Australian intelligence agencies, and it disrupted court systems in Singapore and airline support desks in India.

Microsoft has apologised for the issue, which it said was due to a technical failure rather than a cyber-attack. A spokesperson for the US tech company said the company restored services gradually “given the scale of demand”. “While this took longer, it helped ensure a stable restoration,” the spokesperson said. Microsoft also said email queues were “approaching normal levels” after the global outage hit Outlook and Teams users.

Flora Hamilton, executive director of the Small Business Charter, called the outage a “stark reminder” of how much firms “rely on digital systems” — like Microsoft Outlook — “to keep their operations running”. “For many small and medium-sized enterprises (SMEs), access to email is fundamental to everything from communicating with customers and suppliers to generating income,” she said.

Walter Pasquarelli, an AI strategist, told the BBC that the outage had “put their vulnerabilities and dependence in plain sight” for governments, businesses and critical infrastructure. “Looking ahead, as AI assistants are plugged into our email, calendars and files, a failure like this may spread even further,” he said.

Gergely Orosz, a former leading software engineer at several major tech companies, said outages of this kind were not unheard of, but the unusual part was how long Microsoft took to recover. The disruption that followed showed, Orosz said, “our reliance on a few large US corporations”.

Orosz pointed to one possible safeguard for the future: splitting services by region so that a failure in one area affects fewer users — a precaution he said already exists with Amazon’s cloud computing service, AWS.

Microsoft said it was reviewing what went wrong, and that the findings were expected to inform steps to prevent a similar disruption from happening again.