Syed Saif Ul Hassan 
Nov 18, 2025
An undated image of OpenAI logo is seen in this illustration taken May 20, 2024. — Reuters
It has long been clear that Microsoft is OpenAI's biggest backer, but a question posed by many is how much the ChatGPT maker actually pays to Microsoft, which seems to be answered in leaked documents revealing the scale of its payments to Microsoft.
Citing the purported document, TechCrunch noted that Microsoft received $493.8 million in revenue share payments from OpenAI in 2024. This revenue share surprisingly surged to $865.8 million in the first three quarters of 2025.
The notable point here is that OpenAI reportedly shares 20% of its revenue with Microsoft, after the tech giant made a substantial investment exceeding $13 billion.
What makes this more fascinating is that Microsoft shares its revenue back with OpenAI, returning about 20% from its Bing and Azure OpenAI Service revenues.
These leaked figures indicate Microsoft’s net revenue share, excluding payments made to OpenAI from Bing and Azure royalties. Microsoft does not disclose specific earnings from these services, complicating the estimation of its total revenue share.
Based on the 20% revenue-share figure, OpenAI's revenue for 2024 is estimated at a minimum of $2.5 billion, with projections for the first three quarters of 2025 reaching $4.33 billion.
OpenAI CEO Sam Altman has indicated that the company's revenue could exceed $20 billion annually by year-end, potentially hitting $100 billion by 2027.
OpenAI’s inference costs, which are primarily cash expenditures, are significant, with estimates of $3.8 billion in 2024 and $8.65 billion in early 2025.
These developments suggest that OpenAI may be spending more than its revenue on inference, raising questions about the sustainability of its financial model amid ongoing discussions about the AI industry's future.
