Anthropic opened a major incident on its status page at 09:58 UTC on 13 November, titled “Elevated errors on claude.ai, Claude Code, and platform.claude.com”. Its first update read: “We are investigating an issue with users authenticating to Claude.ai and Claude Code”, according to the Anthropic status page.
Update, 14 November 2026: Anthropic’s status page now marks the login-errors incident resolved at 11:58 UTC on 13 November (“The issue affecting claude.ai and Claude Cowork has been resolved”), about 120 minutes after it opened at 09:58, by our arithmetic. It was not the day’s only incident: a second one, “Elevated errors on claude.ai, the Claude API, and Claude Code”, opened at 13:09 UTC and was resolved at 15:38, about 149 minutes, and unlike the morning incident it named the Claude API. Together the two incidents opened on 13 November ran about 269 minutes, by our arithmetic. Our own number: the status page lists 16 incidents opened in the 31 days from 14 October to 13 November, 10 of them rated major or critical, by our count. The Microsoft 365 connector incident that opened on 12 November was marked resolved at 21:49 UTC on 13 November.
Four of the ten components the status page lists were placed on the incident, by our count: claude.ai at major outage, the Claude Console and Claude Code at partial outage, and Claude Cowork at degraded performance. At 11:05 UTC Anthropic posted that “A fix has been deployed for the issue affecting Claude services and we are monitoring for recovery”. That came 66 minutes after the first post, by our arithmetic.
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The key insight: As we read the status page, the login errors hit the consumer and developer front doors (claude.ai, Claude Code, the Console) while the Claude API and the cloud-partner routes stayed operational.
The 11:05 UTC update set the Claude Console and Claude Code back to operational. It left claude.ai at major outage and Claude Cowork at degraded performance. The incident status moved from investigating to monitoring; the status page lists no resolution time yet.
The Claude API (api.anthropic.com) was not among the components on the incident. The status page showed it as operational when we read it, along with Claude Platform on AWS, Claude in Microsoft Foundry, Claude Models on Google Cloud, Claude for Government and Claude on Cloud Platforms. The overall page read “Partial System Outage”.
Anthropic status page updates on 12 and 13 November 2026 (UTC): the Microsoft 365 connector incident opened at 17:52 on 12 November and was still identified; the login-errors incident opened at 09:58 on 13 November and a fix was deployed at 11:05. Four of ten components is our count; 66 minutes is our arithmetic.
A Second Open Incident: Microsoft 365
A separate major incident opened at 17:52 UTC on 12 November, Elevated errors affecting the Microsoft 365 connector, was still marked identified when we read it. Anthropic’s latest update on it, at 22:23 UTC, said “This issue is caused by a Microsoft 365 service incident, and mail, calendar and search tools in the Microsoft 365 connector are still failing for most requests”, and that Claude for Outlook remains affected.
The incidents land during Anthropic’s share offering. Its European prospectus, filed with the SEC, says the closing of the offer period is “expected to occur on or about November 18, 2026”, with the underwriting agreement “expected to be made on November 18, 2026”. Our Anthropic IPO map tracks the price range and buyers, and our explainer on how the Anthropic IPO works covers the mechanics.
The Structural Read
As we read the timeline, Claude Code and the Console were set back to operational 66 minutes after the first post, by our arithmetic, while claude.ai was still listed at major outage.
As we read the second incident, the Microsoft 365 connector shows a dependency running the other way: Anthropic attributes those failures to a Microsoft 365 service incident, not to its own systems.
Anthropic status page, 13 November 2026, 11:05 UTC
“A fix has been deployed for the issue affecting Claude services and we are monitoring for recovery”
Three Implications
FOR CLAUDE CODE AND CONSOLE USERS The status page set both back to operational at 11:05 UTC; the incident itself was still open, in monitoring.
FOR CLAUDE.AI AND COWORK USERS The status page still listed claude.ai at major outage and Cowork at degraded performance at 11:05 UTC.
FOR MICROSOFT 365 CONNECTOR USERS The status page said mail, calendar and search tools in the connector were still failing for most requests, and Claude for Outlook remained affected.
The framework puts it in one line: “The value proposition shifts from features to integration depth.”
As we read it, integration depth also sets the cost of an outage: the more work runs through claude.ai, Claude Code and connectors such as Microsoft 365, the more a login error or an upstream failure is felt. The framework does not discuss this incident.
Status set at the first update, 09:58 UTC on 13 November 2026 (Anthropic status page): claude.ai at major outage, the Console and Claude Code at partial outage, Claude Cowork at degraded performance. The bar scale and the count of four of ten components are ours.
What Is Not Established
The status page gives no cause for the login errors and no count of affected users. It does not say whether the 13 November incident is linked to the Microsoft 365 one. We did not contact Anthropic, and we relied on the status page only; figures here were read between 11:00 and 11:45 UTC and may change.
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Login errors put four of the ten components on Anthropic’s status page on a major incident on 13 November, by our count, and a fix was deployed 66 minutes after the first post, by our arithmetic, with claude.ai still listed at major outage. The Microsoft 365 connector incident from 12 November was still open.
A note on sourcing. All incident facts come from Anthropic’s status page (status.claude.com), read between 11:00 and 11:45 UTC on 13 November 2026; the offer dates come from Anthropic’s European prospectus filed with the SEC. The count of four of ten components and the 66-minute figure are ours. Reports of the outage on X were used as a lead only. We did not contact Anthropic for this piece.
Gennaro Cuofano is a CRO and tech executive who has worked in AI since late 2015, starting with bringing NLP, natural-language generation, voice and chatbot products to the marketing industry. His background is in law and finance: he holds a Master's degree in Law and an International MBA with an emphasis on corporate finance (LUISS Business School and the University of San Diego, 2012), and worked as a financial analyst at a real-estate investment firm in San Diego and as an assistant controller. His work focuses on business model strategy, business engineering and, more broadly, structural analysis: how companies make money, read from their own filings. He created FourWeekMBA and leads research there and at The Business Engineer, his newsletter on AI and business strategy, with over 95,000 subscribers and more than 1,000 published analyses. His writing has also appeared on Entrepreneur (for example, How to Digitize a Family Business in Europe) and HackerNoon. Find him on LinkedIn and Substack. See how we source.
