Microsoft 365 has gone down for users around the world, leaving people unable to open their email, join meetings or reach the company’s artificial intelligence assistant. The disruption began on Thursday afternoon and spread quickly from the Americas to other regions, turning an ordinary working day into a frustrating wait for the millions of people who depend on Microsoft’s cloud services to do their jobs.
Microsoft first flagged trouble with Exchange Online mailboxes in the Americas at around 10:54 PM Pakistan time on Thursday. Within a short while, the company confirmed that the problem was not limited to one continent and could affect Microsoft 365 users in any region. Reports from users piled up fast. On the outage tracking website Downdetector, complaints about Microsoft 365 began climbing just after midday Eastern Time in the United States, passing 22,000 reports by 12:55 PM. Outlook drew the heaviest wave, with close to 83,000 reports shortly before 1 PM. By around 1:20 PM, reports about Microsoft 365 had passed 47,000 and Outlook reports were nearing 130,000.
For many workplaces, the timing could hardly have been worse. The working day was in full swing across the Americas when the problems began, and offices, schools and government departments that run on Outlook and Teams suddenly found their most basic tools out of reach: email would not load, messages would not send, and meetings could not be joined.
Which Services Are Affected
According to Microsoft’s own status page, the services that could be affected include Exchange Online, which powers Outlook email, along with Microsoft Teams, SharePoint Online, Microsoft 365 Copilot and Microsoft Defender XDR. Users may be unable to open their mailboxes through Outlook on the web, through mobile email apps that connect using Exchange ActiveSync, or through other connection methods. Reports from users also pointed to trouble with OneDrive and the Microsoft Store.
The breadth of that list is what makes this outage so disruptive. Outlook is the email system for countless businesses and public offices, Teams is where their meetings and chats happen, SharePoint holds their shared documents, and Copilot is the assistant many staff now use every day. When one of these services fails, people can usually work around it; when several fail at once, there is very little left to fall back on.
Microsoft has not said how many users are affected in total, and it has not given a time by which service will be fully restored. The company is sharing updates with administrators in the Microsoft 365 admin centre under incident reference EX1550543, with a second reference, MO1550821, also in use. For ordinary users, the best source of information is Microsoft’s public status page and its Microsoft 365 Status account on X.
What Caused the Outage
Microsoft has said that part of its infrastructure is facing unusually heavy load across several regions, and that this is likely behind the connection errors users are seeing. The company is also looking into an unexpected rise in a specific type of service traffic to see whether it added to the strain. It has not blamed any outside attack or named a single failed component, and the investigation is still going on.
In the meantime, Microsoft says it is working hard to limit the damage. The company has paused all deployments, spread connection traffic across its wider worldwide infrastructure, moved more traffic away from the struggling systems, and started restarting the affected servers. In its own words, it is aggressively pursuing every available way to reduce the impact.
This was not Microsoft’s only problem on Thursday. Earlier in the day, the company dealt with a separate disruption to Teams in North America, which it said was fully resolved by around 10:09 PM Pakistan time, before the wider outage took hold. The two events landing on the same day will have tested the patience of users who rely on Teams for most of their working hours.
The outage also follows a similar shock only weeks earlier. In October, a Google Cloud outage disrupted banks, courts and businesses, showing how quickly a failure in one provider’s systems can ripple through organisations that share nothing except a dependence on the same cloud. Microsoft itself suffered a long disruption in July, when its services were limited or unavailable for thousands of users for more than twelve hours.
That dependence is the deeper issue behind Thursday’s outage. Email, calendars, meetings, shared files and AI assistance have moved almost entirely into the cloud, and for most organisations there is no longer a local system to fall back on when the cloud goes down.
For now, the practical advice for users is simple: watch Microsoft’s status page for updates, avoid repeatedly signing in and out in the hope of forcing a connection, and use phone calls or text messages for anything that cannot wait. The next update from Microsoft will show whether its efforts are bringing the service back or whether users face a longer wait before their inboxes and meetings return to normal.
