At least 74 countries have been affected by the Microsoft outage since it was detected after midday US Eastern Time (17:00 GMT) on Thursday.
Microsoft 365 Services, including Teams, Outlook and artificial intelligence software Copilot, are experiencing "connectivity problems", the company said.
From city governments in the US to Australian spy agencies, disruption has been widespread. Here's what's been happening around the world.
US tech giants OpenAI and Anthropic have both reported problems.
OpenAI, which makes ChatGPT, said it was investigating an issue affecting its connections to Microsoft's services, which caused some tools not to work as expected.
Electric truck maker Workhorse Group, which was expected to report third-quarter results on 12 November, rescheduled to 16 November, citing business disruptions caused by the outage.
Meanwhile, officials in some US cities encouraged citizens to call local offices and agencies where needed instead of using email.
The City of Austin in Texas posted on X early on Friday: "Due to an ongoing Microsoft Outlook outage, City of Austin employees cannot receive or send emails at this time.
"City phone lines remain operational, and 911 Emergency services are not impacted."
Courts from Los Angeles to Texas also issued statements warning that communications might be delayed.
In Canada, the public broadcaster CBC reported that a healthcare network running several hospitals in Toronto had declared…
