General practices, police forces and pharmacies across the UK have been disrupted by a widespread outage affecting Microsoft's cloud services. According to BBC News, the problem stems from a surge in demand on Microsoft's servers after multiple systems became unexpectedly unavailable, forcing traffic onto the remaining infrastructure and causing severe strain.
Multiple GP surgeries have instructed patients to avoid submitting messages through their online portals until service is restored, while several major police forces are asking members of the public to telephone their non-emergency line if they need to file a report. The outage has also affected pharmacies' ability to communicate with medical practices and patients, leading to longer waiting times and potential delays in prescription processing.
Microsoft identified the disruption as incident MO1550821, affecting access to multiple Microsoft 365 services including SharePoint, Copilot and Defender XDR alongside email and Teams, according to Microsoft's incident notice. The company stated that the elevated load resulted from many servers becoming unexpectedly unavailable and said it was investigating the root cause, noting it had not identified any recent change linked to the outage, as reported by HC Magazine.
The disruption began at 11:17 a.m. US Eastern Time on Thursday, 12 November. Downdetector recorded nearly 130,000 reports of Outlook problems on Thursday night, while users also reported issues with Copilot and wider Microsoft 365 services.
Which UK services have been affected?
Tim Frank, a general practitioner in Penzance, told the BBC that his surgery had received no emails during the outage and warned that if the disruption to Microsoft's Teams messaging platform continued, it could cause delays and compromise patient care. Medical practices in Hampshire and Shropshire have instructed patients to telephone them or attend the surgery in person if they have urgent needs.
A spokesperson for the National Pharmacy Association stated that the outage was preventing pharmacies from communicating with GP practices and some patients, meaning waits would be longer than normal and some prescription deliveries would face delays.
Metropolitan Police, Greater Manchester Police and North Yorkshire Police have all issued public statements indicating that their online reporting forms may be affected. They have urged people to call 101 with time-critical but non-emergency reports. South Wales Police and Dyfed-Powys Police have reported similar issues and are asking the public to telephone if they need to make contact.
Some teachers have also reported being unable to access their calendars, emails and files stored on cloud servers.
Which services have remained unaffected?
The London Ambulance Service's critical platforms do not rely on Microsoft systems and therefore have not been affected by the outage. Operations at Heathrow, Manchester and Stansted airports are continuing as usual, with no disruption to their services.
UK intelligence operations have remained unaffected by the outage. While some elements of the security services use Microsoft tools, they maintain a separate system dedicated to classified operations that operates independently.
What is the government's response?
Defence minister Luke Pollard told BBC Breakfast that the government was assessing the impact of the outage on its systems and would release a statement once this assessment was completed. A government spokesperson said officials were working closely with Microsoft to evaluate any impact on government services caused by the company's outage.
What caused the outage?
Microsoft and cyber-security experts have ruled out a cyber-attack as the cause of the disruption. The technology company explained that a large number of its servers had become unexpectedly available, meaning traffic was redirected to the servers that remained operational, placing them under excessive strain.
Jake Moore, a cyber-security adviser at ESET, used a traffic analogy to explain the situation:
Just like on a motorway, when you block one lane, you have to put all of the excess traffic through just, say, one or two lanes. Everything goes and backs up. It slows down, and that's what we're seeing here.
Speaking on BBC Radio 4's Today programme, Moore argued that this incident should emphasise the importance of developing contingency communication networks that operate independently of major providers.
Unfortunately, we just put so much emphasis on just a few providers - so when one big one like this goes down, the knock-on effects are just huge.
Nicky Choo, whose cyber-security firm Mimecast uses Microsoft tools, noted that his company had built-in alternative systems to prevent service disruption. Moore also highlighted that traditional telephone lines appeared to be the most reliable form of communication during such incidents.
What happens next?
Microsoft has not published a confirmed restoration time, and its next scheduled status update is not guaranteed to be a deadline for recovery. The company continues working to resolve the outage affecting users worldwide.
