The number has been an open secret in the AI industry for years; now it is on the books. In its Form 10-K for fiscal 2026, filed last week, Microsoft disclosed for the first time that it recorded $24.1 billion in revenue from commercial arrangements with OpenAI, including revenue-sharing payments, and $6 billion in accounts receivable from OpenAI as of June 30, 2026.

The disclosure is the most concrete accounting yet of one of the defining financial relationships of the AI boom. It began in 2019, when Microsoft invested $1 billion to make Azure OpenAI's exclusive cloud partner, and has since grown into roughly $12 billion in total investment. During OpenAI's restructuring last October, Microsoft's stake was reduced from 32.5% to 27%, a holding valued at $135 billion. In April, the two companies amended the partnership again: Microsoft remains OpenAI's primary cloud partner, but OpenAI is now free to offer its products through any cloud provider — a change that allowed the lab to strike a major deal with Amazon and put its models on AWS.

Despite that shift toward multi-cloud, the money keeps flowing in both directions. Microsoft reported it has committed a total of $13 billion to OpenAI, of which $11.9 billion had been funded as of June 30. OpenAI, for its part, has committed to purchase an additional $250 billion in Azure services.

The filing does not break down the $24.1 billion figure — it could include Azure capacity purchased by OpenAI, revenue-sharing tied to OpenAI products, and other commercial agreements — so it should not be read as a pure share of OpenAI's revenue. Still, Bloomberg reported that OpenAI-linked transactions likely account for the majority of Microsoft's roughly $34 billion AI business, possibly up to 70%.

That circular structure — Microsoft invests in OpenAI, OpenAI buys Azure and pays Microsoft, and the revenue returns to Microsoft's income statement — makes the financial relationship unusually hard to interpret, as analysts have noted. What the new disclosure makes unambiguous is the scale of the entanglement: even as OpenAI courts other clouds, it remains one of Microsoft's most financially significant strategic partners in the world.

Sources