Microsoft suffered a major global service disruption beginning on November 12, 2026, affecting Outlook, Exchange Online, Microsoft Teams, Copilot and several connected Microsoft 365 services. The outage disrupted businesses and public-sector organisations across multiple regions before Microsoft confirmed full restoration on November 14. The company attributed the incident to an infrastructure problem following a network capacity upgrade, ruling out a cyberattack and AI agents.
What happened during the Microsoft 365 outage in November 2026?
The disruption began around midday Eastern Time on Thursday, November 12, when users started reporting problems accessing Outlook and other Microsoft services. Many encountered errors while opening inboxes, sending emails or connecting to their organisational accounts. Complaints quickly spread beyond email, affecting applications that depend on Microsoft’s cloud infrastructure.
The incident was tracked through Microsoft’s service-health system under two major references: EX1550543 for Exchange Online and MO1550821 for the wider Microsoft 365 service disruption. Microsoft confirmed that customers could experience difficulties connecting to multiple services, while independent outage tracker Downdetector recorded reports from users in more than 70 countries and territories.
The Associated Press reported that nearly 130,000 users had reported Outlook problems on Downdetector shortly after 1 PM Eastern Time on November 12. The disruption continued into Friday, November 13, with users in Asia also experiencing problems. Microsoft eventually confirmed that the underlying issue had been addressed and that services had been restored to the remaining affected customers and regions on Saturday, November 14.
Which Microsoft services were affected?
Outlook and Exchange Online were at the centre of the disruption, but the impact extended into other Microsoft applications that rely on shared infrastructure and connected services. Some products experienced complete access problems, while others suffered from specific features failing or responding slowly.
- Microsoft Outlook: Users experienced problems opening inboxes, accessing mailboxes and sending or receiving emails.
- Exchange Online: Mailbox connectivity failures affected multiple access methods, including Outlook on the web and other Exchange connections.
- Microsoft Teams: Users reported problems with certain messaging, calendar and collaboration features.
- Microsoft Copilot: Some users experienced difficulties accessing Copilot and its connected Microsoft 365 functionality.
- SharePoint Online: Certain features and services dependent on Microsoft 365 infrastructure experienced interruptions.
- Microsoft Defender XDR: Some security-related capabilities were affected.
- Microsoft Planner and To Do: Certain task-management functions experienced availability problems.
The extent of the disruption varied by application, location and customer environment. Not every feature of every affected product became unavailable. For example, some Teams users could continue using basic messaging and meetings while experiencing difficulties with other connected functions.
How long did the Microsoft outage last?
The disruption extended across Thursday, November 12, Friday, November 13, and into Saturday, November 14. Microsoft initially struggled to restore affected infrastructure, and its recovery efforts continued as engineers worked through connectivity problems and accumulated email backlogs.
Microsoft’s service updates showed gradual improvement rather than an immediate return to normal operations. On Friday, the company reported that services were recovering across multiple regions but warned that users could still experience intermittent access problems and delayed email delivery.
Reuters reported on Friday that Microsoft’s consumer products and services had recovered by 4:10 PM UTC, while enterprise Microsoft 365 services were still undergoing recovery. The company continued monitoring queued email messages and did not consider the enterprise incident resolved until the remaining issues had been addressed.
On Saturday, November 14, Microsoft announced that it had completed the work required to address the underlying issue and restored services to the remaining impacted customers and regions. The company also apologised for the disruption. This makes the incident a multi-day service event, although individual customers experienced different periods of downtime.
What caused the Microsoft 365 outage?
Microsoft attributed the disruption to a technical problem involving an earlier network capacity upgrade that surfaced following a subsequent network change. The company said a portion of its infrastructure became unavailable, creating additional load on the servers that remained operational.
During its investigation, Microsoft identified servers that were unexpectedly failing automated health checks. Attempts to return some of these servers to service were initially unsuccessful, and the resulting infrastructure imbalance created further connectivity problems.
Microsoft’s engineers worked on restoring affected servers, managing traffic and rebuilding selected infrastructure using previous software configurations. The company also introduced protective traffic-management measures to reduce pressure on affected systems while recovery continued.
There is an important distinction between the original infrastructure issue and the recovery process. Even after some servers became available again, Microsoft had to verify their stability under renewed traffic and address the backlog of delayed email messages. Restoring access to Outlook did not automatically mean that every queued message had been processed.
Was the Microsoft outage caused by a cyberattack or artificial intelligence?
No. Microsoft explicitly stated that the incident was not related to a cyberattack, malicious activity or AI agents. The company attributed the disruption to the infrastructure and network configuration issue associated with an earlier capacity upgrade.
The clarification mattered because the outage affected both traditional productivity applications and AI-powered services such as Copilot. However, the fact that an AI product experienced disruption does not establish that artificial intelligence caused the underlying technical failure.
Microsoft had not published its complete post-incident review as of November 15, 2026. Further technical details about the precise failure mechanism and the measures being introduced to prevent a recurrence will depend on that report.
Did the Microsoft outage affect businesses and government organisations?
Yes. The disruption extended beyond individual users and affected organisations that depend on Microsoft 365 for internal communication, document access, scheduling and operational coordination.
The Associated Press reported interruptions involving government departments, courts, healthcare services, airlines, banks and businesses. In the United Kingdom, the disruption contributed to delays in court proceedings and affected some online police reporting services. The National Pharmacy Association also warned of possible delays involving prescriptions and pharmacy services.
Government operations in countries including Japan, Singapore and Australia were among those affected. Some organisations experienced problems with official email communications and other Microsoft-dependent systems.
The incident also demonstrated how disruptions to a single cloud provider can spread across seemingly unrelated activities. When email, collaboration tools and connected business applications depend on the same underlying infrastructure, a technical failure can affect several operational processes simultaneously.
Can businesses claim compensation or SLA credits from Microsoft?
Potentially, but businesses should not assume that every affected customer automatically qualifies for a refund. Microsoft’s Service Level Agreements specify availability commitments for eligible online services, and the applicable service-credit provisions depend on the subscription, contract and measured service availability.
Microsoft publishes its online-services SLA documentation, including its October and November 2026 editions. Enterprise administrators should review the agreement applicable to their subscription and determine whether the incident qualifies under its specific terms.
Microsoft’s credit-request procedures require supporting evidence. Depending on the purchasing arrangement, this can include:
- The affected customer or tenant identification details.
- The relevant Microsoft service incident reference, such as EX1550543 or MO1550821.
- Evidence of the actual service disruption and its duration.
- The number and locations of affected users, where applicable.
- Relevant support tickets and documentation of the reported impact.
Microsoft does not automatically issue a universal 50% refund for this outage. The final credit, if any, depends on the applicable SLA and the customer’s eligibility. Businesses should contact their Microsoft administrator, account representative or support provider to establish the correct claims process.
Frequently asked questions
Is Microsoft 365 working again after the November 2026 outage?
Yes. Microsoft confirmed on November 14 that it had addressed the underlying issue and restored service to the remaining affected customers and regions. Administrators should still consult the Microsoft 365 admin centre for any subsequent service-specific notices.
Was Microsoft Copilot down during the outage?
Some Microsoft Copilot services and connected features experienced disruption. The impact was associated with the wider Microsoft 365 infrastructure problems rather than an independently confirmed failure of the underlying AI technology.
How many countries were affected?
Downdetector received reports from users in more than 70 countries and territories. This represents the geographical spread of reported problems, not a verified count of countries where every Microsoft service was unavailable.
Has Microsoft published a full investigation report?
Microsoft said it would provide a post-incident report after completing its review. As of November 15, the company had communicated the preliminary technical cause and recovery measures, but a complete public investigation was not yet available.
What the Microsoft 365 outage means for cloud reliability
The November 2026 disruption exposed the operational risks of relying heavily on a single cloud ecosystem for email, collaboration, security and business applications. Microsoft’s infrastructure problem affected services across multiple regions, demonstrating how a failure in shared systems can create wider consequences for organisations that depend on uninterrupted connectivity.
Microsoft has confirmed the restoration of affected services and identified an earlier network capacity upgrade followed by a subsequent network change as the source of the incident. Its forthcoming post-incident review will provide further insight into the technical failure and preventive measures. How should businesses prepare for another disruption of this scale: maintain alternative communication systems, diversify cloud providers or invest more heavily in offline operational backups?
