Bigger than Bing or Xbox: Microsoft’s OpenAI haul reaches $10B in quarterly revenue

OpenAI generated $10 billion in revenue for Microsoft in the quarter ended Sept. 30, about 11% of the Redmond company’s total revenue, according to its quarterly filing Wednesday.
The amount is up sharply. In the fiscal year that ended in June, Microsoft recorded $24.1 billion in revenue from its business with OpenAI, or about $6 billion a quarter on average.
That $10 billion surpasses some of Microsoft’s longest-running businesses. Xbox brought in $5.4 billion in the quarter. Search and advertising, which includes its Bing search engine, generated $6.6 billion. Windows licenses sold through PC makers, along with Surface and other Microsoft devices, brought in $3.6 billion.
The total covers revenue-sharing payments from OpenAI, as well as other business between the companies, such as OpenAI’s use of Azure to train and run its AI models. Microsoft didn’t say how much came from each, or how much of Azure’s growth came from OpenAI.
Azure revenue rose 48% to $33.2 billion in the quarter, beating Wall Street’s expectations and the company’s own forecast of 44% to 45% growth.
Microsoft has begun disclosing its revenue from OpenAI because its stake of about 24% makes OpenAI a “related party” under accounting rules, requiring it to report the business they do with each other.
Microsoft first reported the number in its annual report in July, as a full-year total. This is the first time it has given a quarterly figure.
The original AI alliance: Microsoft first invested in OpenAI in 2019, eventually committing $13 billion, and became its exclusive cloud provider. ChatGPT ran on Azure when it launched in late 2022.
The companies have loosened their ties since then. OpenAI restructured as a public benefit corporation in October 2025, and Microsoft gave up its right of first refusal to supply OpenAI’s computing capacity. OpenAI committed to buy an additional $250 billion in Azure services. An April 2026 agreement gave OpenAI broader freedom to use other cloud providers.
OpenAI has also agreed to keep sharing revenue with Microsoft through 2030.
In addition, Microsoft sells access to OpenAI’s models to business customers through its Azure OpenAI Service, and the models became the foundation for its Copilot products, putting Microsoft at the front of the generative AI boom. That revenue comes from Microsoft’s own customers, so it isn’t part of the $10 billion.
Microsoft, for its part, now builds its own AI models and offers models from Anthropic and others.
Many customers, not a few: Asked by Bernstein Research analyst Mark Moerdler whether AI growth on Azure was coming from big businesses or AI-native companies, Microsoft CEO Satya Nadella didn’t mention OpenAI.
He said he doesn’t want Azure’s AI business to depend on a few big customers, and that broad adoption by businesses is just getting started.
Nadella described it as “a decade-long thing,” and contrasted it with relying on “four customers who buy a lot of capacity from you” to show a few quarters of growth. That, he said, is “not a business as far as I’m concerned.”
He added that Microsoft has large customers who want to buy capacity, “and as long as the pricing is right, we may sell them some. If not, we will be patient.”
Later in the call, Goldman Sachs analyst Gabriela Borges brought up the fact that OpenAI made up 11% of revenue. Nadella didn’t address the number but praised OpenAI’s latest models and said customers are increasingly mixing models from different companies, or training their own.
He cited Microsoft’s tools for routing each task to whichever AI model handles it best. If you use AI coding agents, Nadella said, you want Anthropic and OpenAI “to compete for your workload, not like once a quarter, but for every task.”
New risk language: Microsoft also expanded a warning in its quarterly filing about the risks of depending on outside AI providers. The company builds products such as Copilot on AI models from outside companies, including OpenAI and Anthropic. It now says it has “limited visibility into or control over” how those models are designed, trained, secured and tested.
Without naming OpenAI or Anthropic, the same section notes that some of these AI partners are also “significant customers of Azure,” and that the benefits Microsoft expects from those relationships “may not be realized or sustained.” It says those partners could change how much they buy, and that Microsoft itself may change how it allocates scarce data center capacity or prices it.
Microsoft is an investor in both companies. According to its latest filing, it owns about 24% of OpenAI, down from about 25% in June and about 27% after OpenAI’s restructuring a year ago, and has put $12.0 billion of a promised $13.0 billion into the company.
In addition, Microsoft agreed last year to invest up to $5 billion in Anthropic, and its results for the June quarter included a $3.2 billion gain on that investment. Microsoft hasn’t disclosed the size of its Anthropic stake, and Anthropic’s IPO filing earlier this week didn’t specify it either.