Here’s everything we know about the global Microsoft outage
A major global outage affecting Microsoft services has disrupted access to several platforms, including email services and artificial intelligence products, leaving individuals, businesses and public institutions struggling to carry out their usual activities.
Microsoft has ruled out a cyberattack as the cause of the disruption, attributing the problem to technical difficulties within its infrastructure. However, efforts to restore normal operations have so far faced challenges.
Here is a breakdown of the affected services, the scale of the disruption and what may have caused the outage.
What happened?
Several Microsoft 365 services, including Teams, Outlook and its artificial intelligence platform Copilot, have experienced connectivity issues.
Users have reported different levels of disruption, with some unable to send or receive emails, access certain files or retrieve information from their calendar applications.
However, the impact has not been uniform. Some customers have continued using Microsoft Teams, including its messaging and online meeting features, without major difficulties.
How many people have been affected?
Microsoft’s website indicates that more than 430 million people use its Microsoft 365 applications worldwide.
Although the company has yet to establish the total number of affected users, outage-monitoring platform Downdetector recorded reports from approximately 140,000 people across 74 countries experiencing Outlook problems on Thursday evening.
The actual number of affected users is believed to be significantly higher, as Downdetector largely depends on individuals voluntarily reporting service disruptions.
Given the widespread use of Microsoft 365 by organisations and businesses globally, the outage has also affected other technology platforms.
OpenAI and Anthropic, two major artificial intelligence companies, have both reported disruptions linked to the Microsoft outage.
OpenAI, the developer of ChatGPT, said it was investigating connectivity problems involving Microsoft’s services, which had affected the performance of some of its tools.
The disruption has been reported across several countries, affecting institutions ranging from local government authorities in the United States to intelligence agencies in Australia.
Courts in Los Angeles and Texas have also warned that some communications could experience delays.
In Canada, public broadcaster CBC reported email problems at a healthcare network operating several hospitals in Toronto, although patient care remained unaffected.
Japan’s government also confirmed disruptions to its shared information technology platform.
In the United Kingdom, several public services, including general practitioner (GP) surgeries, pharmacies, police departments and schools, have experienced difficulties.
Some GP practices have advised patients against submitting enquiries through their websites until the problem is resolved, while several police forces have encouraged the public to make reports by telephone.
What has Microsoft said?
Microsoft has dismissed suggestions that the disruption resulted from a cyberattack, explaining that the problem was caused by unusually high demand on its infrastructure.
The company described the situation as “elevated load”, meaning its servers were experiencing significantly more pressure than they normally handle.
According to Microsoft, an unexpected number of servers became unavailable, forcing additional traffic onto the remaining operational servers and placing them under further strain.
On Friday afternoon, the company reported signs of improvement, particularly in Europe, while noting that recovery efforts were also progressing in North America.
It said its priority was to resolve the remaining disruptions, cautioning that some customers could continue experiencing intermittent problems as engineers worked to restore services.
In a subsequent update, Microsoft said the situation was improving, with email backlogs substantially reduced and approaching normal levels.
Why has it taken so long to resolve?
Although some Outlook users have started regaining access to their accounts, the disruption has lasted more than 20 hours, an unusually lengthy period for an outage of this nature.
Professor James Ferryman of the University of Reading’s Department of Computer Science suggested that Microsoft’s explanation points to problems involving the systems responsible for establishing secure connections to its servers.
He explained that when these systems become overwhelmed, servers may stop responding to requests.
According to him, the situation can quickly escalate because when one server fails, its workload is transferred to another, placing additional pressure on the remaining infrastructure.
At the same time, millions of devices continue attempting to reconnect, further increasing demand.
He noted that restoring the services requires a gradual process rather than switching everything back on simultaneously, as engineers must carefully manage the growing volume of reconnection requests.
Gergely Orosz, a former senior software engineer who has worked with major technology companies, including Skype and Uber, described the incident as potentially one of the most disruptive business email outages ever recorded.
Although the exact number of affected users remains unclear, he said he could not recall a disruption to business email services that had taken this long to return to normal operations.
Australian cybersecurity expert Troy Hunt also warned that the outage could have significant consequences because of Microsoft’s central role in the global internet ecosystem.
He observed that the incident highlights how essential email remains to everyday activities, including workplace communication, appointment management, online purchases requiring verification and the creation or access of digital accounts and services.
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