Microsoft pays outage credits only on a claim, and this week's must arrive by 31 December
Microsoft 365 mailboxes failed at 16:17 UTC on Thursday 12 November, according to Microsoft's service notices as CIO quotes them. At 20:02 UTC on Friday, 27 hours and 45 minutes later, Microsoft was still clearing queued mail and said: "We do not have an ETA for full recovery yet", The Register reports. Copilot Chat would not load for some users. Anthropic said the tools that let Claude read Outlook mail and calendars were failing for most requests, CX Today reports. CIO has since noted Microsoft's announcement that it has fixed the underlying issue and is restoring services.
Why it matters: Microsoft's Service Level Agreement, the contract behind its uptime promise, pays nothing until the customer files a claim, and Microsoft must receive it by the end of the month after the incident: 31 December 2026. For Exchange Online, the mail service behind Outlook, the credit is 25% of the month's fee when the service worked less than 99.9% of the month, 50% below 99% and 100% below 95%. Microsoft counts by user and by minute. November has 43,200 minutes. A company whose every user had no mail for 27 hours, 1,620 minutes, sits at 96.25% and in the 50% tier.
The catch: The credit is capped at one month's fee for the service that failed. The agreement says credits "will not be awarded to compensate for any other forms of loss, including but not limited to lost revenue, operational costs". Slow service does not count; for mail, only time when users could not send or receive in the browser version of Outlook. Copilot has separate terms that count questions in Copilot Chat that fail with a server error, and they do not say whether a chat that will not load qualifies. Microsoft's outage notices "are not a confirmation" of eligibility.
What to do: Ask your Microsoft 365 administrator to save the evidence this week: when mail and Copilot stopped and came back, how many users in which offices, and the error messages, under Microsoft incident numbers EX1550543 and MO1550821. The agreement lists those items and warns: "Failure to provide the required information will result in claims being rejected." File one claim for each affected service by 31 December. If you buy through a reseller, ask it today who files. Have finance set the largest possible credit beside the hours your teams lost, and bring both to the next renewal.
Looking ahead: Microsoft says the outage was not caused by a cyberattack or by AI and has promised a full report after its review, CIO reports.
Our coverage →Microsoft: Service Level Agreement for Online Services (October 2026 edition, read 14 Nov 2026) ↗CIO: Microsoft struggles to get M365 services back online after widespread outage (13 Nov 2026) ↗CIO: M365 services slowly come back online after global outage (13 Nov 2026) ↗The Register: Microsoft's massive M365 outage stretches past 27 hours as its fixes keep failing (13 Nov 2026) ↗CX Today: Microsoft Outage Cut Agents Off From the Contact Center (13 Nov 2026) ↗