Microsoft outage highlights reliance on major technology providers

Microsoft says it is reviewing a technical failure behind a global outage that disrupted Microsoft 365 for more than 22 hours, after the incident exposed businesses’ and public services’ reliance on a small number of technology providers.

The outage affected services including Outlook. Microsoft said routine automated checks took some servers offline, overloading those that remained. Engineers restored services gradually, and the company said the issue was not caused by a cyber-attack.

Around 430 million people worldwide use Microsoft 365, while problems were reported in more than 70 countries. The disruption affected organisations beyond businesses: email systems at the US House of Representatives and Australian intelligence agencies were knocked out, while court systems in Singapore and airline support desks in India were also hit.

Flora Hamilton, executive director of the Small Business Charter, said the outage was a “stark reminder” of how much firms rely on digital systems. For small and medium-sized businesses, she said, email can be fundamental to communicating with customers and suppliers and generating income.

Technology strategist Walter Pasquarelli said the outage had made the vulnerabilities and dependence of governments, businesses and critical infrastructure “plain in sight”. He warned that failures could have wider effects as AI assistants become connected to email, calendars and files.

Gergely Orosz, a former software engineer at major technology companies, said the length of time Microsoft took to recover was unusual, although outages of this kind were not unheard of. Microsoft said the scale of demand led it to restore services gradually, adding that the slower process helped ensure a stable recovery.

Orosz said the disruption showed the risks of relying on a few large US corporations. He suggested that dividing services by region could limit the impact of future failures. Microsoft said its review of the incident would inform steps to prevent a similar outage. The disruption followed a global Microsoft 365 outage that affected Outlook, Teams and Copilot.