After a year of frantic deal-making and rumors of an upcoming IPO, the financial scrutiny of OpenAI is intensifying. Leaked documents obtained by tech blogger Ed Zitron offer more insight into OpenAI’s finances — specifically, its revenue and computational costs over the past few years.
Zitron reported this week that by 2024, Microsoft will receive $493.8 million in revenue share payments from OpenAI. In the first three quarters of 2025, that number jumped to $865.8 million, according to documents he saw.
OpenAI reportedly shares 20% of its revenue with Microsoft as part of a previous deal in which the software giant invested over $13 billion in the powerful AI startup. (Neither the startup nor the folks at Redmond have publicly confirmed that percentage.)
This is where things get a little sticky though, because Microsoft also shares revenue with OpenAI, kicking back around 20% of revenue from Bing and Azure OpenAI Service, a source familiar with the matter told TechCrunch. Bing is powered by OpenAI, and the OpenAI service sells cloud access to OpenAI’s models to developers and businesses.
The source also told TechCrunch that the leaked payments refer to Microsoft’s net revenue share, not gross revenue share. In other words, they don’t include what Microsoft paid to OpenAI from Bing and Azure OpenAI royalties. Microsoft subtracts those numbers from its internally reported revenue share figures, according to this person.
Microsoft doesn’t break out how much it earns from Bing and Azure OpenAI in its financial statements, so it’s hard to estimate how much the tech giant is kicking back.
Nevertheless, the leaked documents provide a window into the hottest company in the private markets today — and not just how much it’s making in revenue, but also how much it’s spending relative to that revenue.
Techcrunch event
San Francisco
|
13.-15. October 2026
So based on the widely reported 20% revenue share statistic, we can deduce that OpenAI’s revenue was at least $2.5 billion in 2024 and $4.33 billion in the first three quarters of 2025 – but very likely will be more. Previous reports from The Information estimate OpenAI’s 2024 revenue at around $4 billion and its revenue from the first half of 2025 at $4.3 billion.
Altman also recently said that OpenAI’s revenue is “well more” than reports of $13 billion a year, will end the year above $20 billion in annual revenue (which is a projection, not a guide to actual revenue), and that the company may even reach $100 billion by 2027.
According to Zitron’s analysis, OpenAI may have spent about $3.8 billion on inference by 2024. That spending rose to about $8.65 billion in the first nine months of 2025. Inference is the computation used to run a trained AI model to generate answers.
OpenAI has historically relied almost exclusively on Microsoft Azure to provide computing access, although it has also entered into agreements with CoreWeave and Oracle, and more recently with AWS and Google Cloud.
Previous reports estimate OpenAI’s total computing spend at around $5.6 billion for 2024 and its “revenue costs” at $2.5 billion in the first half of 2025.
A source familiar with the matter told TechCrunch that while OpenAI’s training expenses are mostly non-cash — meaning they’re paid for by credits that Microsoft awarded OpenAI as part of its investment — the company’s closing expenses are mostly cash. (Training refers to the computational resources required to initially train a model.)
While not a complete picture, these numbers suggest that OpenAI could be spending more on closing costs than it is earning in revenue.
And these implications promise to add to the incessant AI bubble talk that has seeped into every conversation from New York City to Silicon Valley. If modeling giant OpenAI really is still in the red running its models, what could that mean for the massive investments in mind-blowing valuations for the rest of the AI ​​world?
OpenAI declined to comment. Microsoft did not respond to TechCrunch’s request for comment.
Do you have a sensitive tip or confidential documents? We report on the inner workings of the AI ​​industry – from the companies shaping its future to the people affected by their decisions. Contact Rebecca Bellan at rebecca.bellan@techcrunch.com or Russell Brandom at russell.brandom@techcrunch.com. For secure communication, you can contact them via Signal at @rebeccabellan.491 and russellbrandom.49.