Leaked documents shed light into how much OpenAI pays Microsoft (techcrunch.com)

Leaked documents obtained by blogger Ed Zitron reveal how much OpenAI has been paying Microsoft under their partnership: roughly $493.8M in revenue-share payments in 2024 and $865.8M in the first three quarters of 2025. Those figures align with widely cited but unconfirmed reports that OpenAI shares about 20% of revenue with Microsoft following a multibillion-dollar investment; however, sources say the leaked numbers represent Microsoft’s net revenue share (after Microsoft’s own payouts back to OpenAI from Bing and Azure OpenAI Service), complicating simple revenue math. Using the 20% rule as a rough gauge implies OpenAI generated at least ~$2.5B in 2024 and ~$4.3B in the first three quarters of 2025, though other reports and CEO Sam Altman’s statements suggest materially higher annualized revenue. The documents also shed light on compute economics: Zitron estimates OpenAI spent ~$3.8B on inference in 2024 and ~$8.65B in the first nine months of 2025. Training costs appear largely covered by Microsoft credits tied to its investment, while inference — the cash-heavy compute used to run models — is paid out of pocket. If those inference estimates hold, OpenAI may be spending more on model serving than it takes in, a dynamic that raises questions about near-term profitability and the sustainability of high valuations across the AI sector. Ambiguities around net vs. gross revenue sharing, undisclosed Bing/Azure earnings, and nonpublic deals with other cloud providers (CoreWeave, Oracle, AWS, Google) mean the full financial picture remains opaque.