Microsoft made 10 billion dollars from OpenAI in three months: a partner that is increasingly a rival now brings in almost 11 percent of its revenue

In a regulatory filing, Microsoft has revealed how much it actually earns from OpenAI. From its agreements with the company, including revenue sharing, it made around 10 billion dollars (about 8.6 billion euros) in the quarter that ended on September 30. That's almost 11 percent of Microsoft's total quarterly revenue of 92.3 billion dollars.

For the whole of fiscal 2026, revenue from OpenAI reached 24.1 billion dollars. If the pace of the last quarter continues, the annual figure is heading towards 40 billion. For comparison: according to leaked documents, Microsoft received 865.8 million dollars net from revenue sharing in the first nine months of 2025. The jump is enormous, and until now both companies have rarely spoken openly about the numbers.

How much of the money comes from revenue sharing and how much from OpenAI using Azure cloud services, the filing doesn't say. According to earlier reports, OpenAI gives Microsoft 20 percent of its revenue, but neither company has officially confirmed that. Under the April 2026 agreement, revenue sharing continues until 2030, with a cap, and OpenAI is allowed to work with rival cloud providers.

Then there's the debt. At the end of September, OpenAI owed Microsoft 7.2 billion dollars for transactions already made, up from 6 billion at the end of June. That isn't new revenue - it's money that hasn't arrived yet. When your biggest partner owes you more and more, that's a number worth watching.

At the same time, Microsoft's stake in OpenAI is shrinking. From about 27 percent after the October 2025 recapitalisation, it fell to around 25 percent in June and 24 percent in September. Microsoft doesn't explain what caused the drop. That same October 2025, Microsoft gave up its exclusive right over OpenAI's cloud, and in return OpenAI promised to buy an additional 250 billion dollars of Azure services.

The paradox is obvious: the two companies increasingly fight for the same corporate customers, while being ever more tightly bound financially. It's a marriage of convenience of the kind the Balkans know well - partners on paper, rivals on the ground, and the last word belongs to whoever owns the servers. How long can a relationship like this last before someone files for divorce?