Microsoft outage leaves UK businesses chasing compensation they may not get

More than 20 hours after Microsoft 365 services crashed, British organisations are discovering that compensation claims are harder to win than the outage itself.

The outage started on November 12th, disrupting Microsoft 365, Copilot, Outlook, Teams and other services across 74 countries. Downdetector recorded 140,000 reports of Outlook problems from users worldwide that Thursday evening.

The disruption paralysed systems used by schools, healthcare, courts and governments across the UK. GP surgeries, pharmacies and police were hit. NHS England said local services were using longstanding measures to manage IT outages, including other IT systems or paper records where possible.

Pharmacists and National Rail warned of delays in issuing some prescriptions because some pharmacies couldn’t communicate with GP practices and patients. They said passengers might be unable to access tickets sent by email, and advised them to log into the website or app where they bought them.

At Minshull Street crown court in Manchester, juries in some cases were sent home early due to IT failure. The Outlook outage also hit the Bank of England and the Financial Conduct Authority, though a bank spokesperson said all critical operations were running normally.

Asda online customers faced problems registering, resetting passwords and changing email addresses. Natwest was among the financial services firms affected by the disruption.

Microsoft said heavy demand on its infrastructure had left many servers unexpectedly unavailable, and that the outage wasn’t a cyber-security incident. It knew of no malicious activity behind the disruption.

Microsoft’s website says its 365 apps have over 430 million users.

For its paid services, Microsoft's service level agreement typically promises uptime of 99.9% or more. The SLA applies to paid customers, including businesses, government and educational organisations, as well as Cloud Solution Provider customers.

Microsoft 365 Personal and Family subscriptions fall outside the SLA, which applies instead to business plans. An organisation may be able to claim compensation for a Microsoft 365 business subscription.

• Sectors affected GP surgeries, pharmacies, police and schools across the UK.
• Healthcare NHS England trusts and ambulance services, with emergency callouts unaffected.
• Justice Manchester crown court sent juries home early; staff searched for fax machines.
• Finance Bank of England, Financial Conduct Authority, Natwest and Asda.

A Reddit user said Microsoft's service level agreement allows 44 minutes of downtime per month, with 25% of the monthly service credit if service is down longer than that and 50% if it is unavailable for more than seven hours. Compensation terms can differ by service under Microsoft's Service Level Agreement for Microsoft Online Services, dated 1 November 2026.

Eligible customers receive service credit for future use, not money back. One Microsoft customer said they’d previously received a $900 credit, though it took three months and extensive follow-up emails.

Microsoft and Amazon Web Services are estimated to control 70 to 80 per cent of the UK’s public cloud market. When one company runs cloud services, email, documents and collaboration tools, a single failure brings them all down together, said Mark Boost, chief executive of UK cloud provider Civo.

Microsoft said on Friday it was making further progress toward recovery, gradually restoring traffic after the disruption affected 74 countries. Email queues were much lower and nearing normal levels, with recovery improving in Europe and North America.

Microsoft said it wasn’t aware of any malicious activity causing the incident and promised a post-incident report once it was fully resolved.