Anthropic vs OpenAI: The Revenue Accounting Gap Explained

Anthropic's annualized revenue reportedly exceeds $65 billion this year, while OpenAI projects over $40 billion. That $25 billion gap looks decisive, but it's partly an accounting difference. Anthropic records the full value of Claude sales through cloud partners as revenue, then books the cloud providers' cuts as expenses. OpenAI reports only the portion it keeps from partner-enabled sales. For builders evaluating which AI lab to partner with or build on, the headline numbers don't tell the full story.

How the Accounting Works

The core difference is gross versus net revenue recognition. When a customer buys Claude through AWS or GCP, Anthropic counts the entire transaction as revenue and then records the cloud platform's cut as a cost. OpenAI, for similar partner-enabled sales, reports only the amount it retains. Khosla Ventures partner Ethan Choi explained that Anthropic counts revenue on a gross basis, meaning it does not subtract the cut it pays to third-party platforms in the same way that OpenAI does. Neither approach is definitively wrong, accounting professor Francine McKenna told Axios, but the divergence can materially change headline ARR figures.

Why the Enterprise Mix Matters

The revenue recognition difference is only part of the story. The two companies have fundamentally different customer bases. Approximately 85% of Anthropic's revenue comes from enterprise and developer customers, while roughly 85% of OpenAI's revenue is tied to ChatGPT consumer subscriptions, with about 95% of those users paying nothing. Enterprise revenue tends to be stickier and higher-margin, which may justify some of the gap even after accounting adjustments. Both companies still spend more than $1 for every $1 of revenue, with Anthropic's total expense load at $2.16 per revenue dollar and OpenAI's cash burn adding to a high cost of goods sold.

What the IPO Filings Will Reveal

Investors are watching how each company will justify its revenue treatment in upcoming IPO filings. The SEC is likely to scrutinize the divergence, as Forbes reported that reasonable arguments exist on both sides of the principal-agent determination for hyperscaler marketplace sales. Choi noted the regulatory tension directly: "If they both IPO in the coming quarters, not sure how the SEC is going to let these two companies have different accounting treatment for essentially the same type of revenue." The IPO documents will finally show how Anthropic justifies its gross reporting and whether OpenAI's net approach is more conservative.

The Bottom Line for Builders

For AI builders and product teams, the key takeaway is that headline ARR comparisons between Anthropic and OpenAI are misleading without understanding the accounting. The $25 billion gap is real in reported terms, but a meaningful portion comes from different revenue recognition rules rather than actual market demand. Until IPO filings provide full transparency, focus on product traction, enterprise adoption, and developer ecosystem rather than reported revenue run rates. Anthropic may genuinely be growing faster, but the current numbers overstate the lead.