Unveiling OpenAI’s Financial Dynamics: Leaked Documents Reveal Payments to Microsoft
Recent revelations have provided a deeper understanding of the financial relationship between OpenAI and Microsoft, two titans in the artificial intelligence sector. Leaked documents obtained by tech blogger Ed Zitron shed light on the substantial revenue-sharing payments OpenAI has made to Microsoft over the past two years.
In 2024, OpenAI reportedly transferred $493.8 million to Microsoft as part of their revenue-sharing agreement. This figure saw a significant increase in the first three quarters of 2025, with payments reaching $865.8 million. These transactions are rooted in a prior arrangement where Microsoft invested over $13 billion into OpenAI, securing a 20% share of OpenAI’s revenue. It’s important to note that neither OpenAI nor Microsoft have publicly confirmed this percentage.
The financial interplay between the two companies is multifaceted. Microsoft, in turn, shares approximately 20% of the revenues generated from Bing and the Azure OpenAI Service with OpenAI. Bing, Microsoft’s search engine, is powered by OpenAI’s technology, and the Azure OpenAI Service offers cloud access to OpenAI’s models for developers and businesses. A source familiar with the matter indicated that the leaked figures pertain to Microsoft’s net revenue share, excluding the amounts paid to OpenAI from Bing and Azure OpenAI royalties. Microsoft deducts these figures from its internally reported revenue share numbers.
Estimating the exact amount Microsoft returns to OpenAI is challenging, as Microsoft does not disclose specific earnings from Bing and Azure OpenAI in its financial statements. However, the leaked documents offer a glimpse into OpenAI’s financial health, highlighting both its revenue streams and expenditure patterns.
Based on the 20% revenue-sharing metric, it’s inferred that OpenAI’s revenue was at least $2.5 billion in 2024 and $4.33 billion in the first three quarters of 2025. These figures align with previous reports suggesting OpenAI’s 2024 revenue was around $4 billion, with $4.3 billion generated in the first half of 2025.
OpenAI’s CEO, Sam Altman, has projected that the company’s revenue is well more than the reported $13 billion annually. He anticipates ending the year with an annualized revenue run rate exceeding $20 billion and envisions reaching $100 billion by 2027.
The documents also shed light on OpenAI’s expenditure, particularly concerning inference costs—the computational resources required to run trained AI models and generate responses. In 2024, OpenAI’s inference expenses were approximately $3.8 billion, escalating to about $8.65 billion in the first nine months of 2025.
Historically, OpenAI has predominantly relied on Microsoft’s Azure for computational needs. However, the company has diversified its partnerships, striking deals with CoreWeave, Oracle, AWS, and Google Cloud. Notably, OpenAI entered into a five-year, $11.9 billion agreement with CoreWeave, receiving $350 million in equity as part of the deal. Additionally, OpenAI agreed to pay Oracle $30 billion annually for data center services.
A source familiar with the matter revealed that while OpenAI’s training expenditures are mostly non-cash—covered by credits from Microsoft’s investment—the inference costs are largely cash-based. This distinction underscores the financial challenges OpenAI faces, as its spending on inference may surpass its revenue.
These financial insights contribute to the ongoing discourse about the sustainability and profitability of AI ventures. If a leading entity like OpenAI is operating at a loss, it raises questions about the viability of substantial investments in the AI sector.
Both OpenAI and Microsoft declined to comment on these revelations.
