AI Revenue Is a Lie: How Anthropic and OpenAI Count Money Differently — and Why It Matters Before IPO

Same Industry. Same Business. Completely Different Math.

Antropic just hit $19 billion ARR. OpenAI is at $25 billion. Tech press runs the comparison breathlessly, as if these are numbers from the same spreadsheet.

They're not.

The two most important AI companies in the world are counting revenue in fundamentally different ways — and investors who are about to be asked to value one or both of them at public-market prices deserve to know that before the roadshow.

The Gross vs. Net Problem

Here's the mechanics, per a widely-circulated analysis by Ethan Choi, a partner at Khosla Ventures:

OpenAI reports revenue from its Microsoft Azure partnership on a net basis. Microsoft takes roughly 20% of revenue as a share. OpenAI deducts that before reporting its top line. You see the number after the haircut.

Anthropic reports revenue from its Amazon Web Services and Google Cloud partnerships on a gross basis. The hyperscaler's cut stays in the top-line number. You see the number before expenses that Anthropic will never actually collect.

The difference isn't accounting pedantry. It's billions of dollars.

Bank of America analysts estimated in March 2026 that Anthropic could pay hyperscale cloud providers up to $6.4 billion in revenue-sharing agreements in 2026 alone — up from $1.9 billion in 2025. That's money Anthropic books as revenue and then hands back. If you're modeling growth, you're modeling a number that includes $6 billion+ that isn't staying at the company.

How the Partnerships Actually Work

OpenAI's revenue-sharing arrangement with Microsoft dates to 2019. Leaked documents confirmed Microsoft receives 20% of OpenAI's revenue — and that OpenAI reports the net figure after that deduction. During the first half of calendar year 2025, Microsoft received $454.7 million from OpenAI, consistent with that net-reporting framework.

Anthropic distributes Claude through AWS Bedrock and Google Cloud Vertex AI. Both take a percentage of end-customer revenue. Unlike OpenAI, Anthropic appears to report the full gross amount billed through those channels before the cloud partners' take comes off the top. Anthropic's ARR hit $19 billion annualized as of March 2026, up from $9 billion at end of 2025. A material portion of that growth reflects revenue that gets remitted to Amazon and Google.

The Accounting Rule in Question

Under ASC 606 — the U.S. revenue recognition standard — whether you report gross or net turns on a single question: are you a principal or an agent?

A principal controls the good or service before delivery, bears fulfillment risk, and recognizes full transaction price. An agent facilitates the sale, takes a fee, and recognizes only what it keeps.

Applied to AI model distribution through hyperscaler marketplaces, this is genuinely ambiguous — and that ambiguity is exactly what the SEC will scrutinize when either company files an S-1. The SEC has a long history of pressing companies on this exact judgment in cloud and software reseller contexts.

Choi put it 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."*

Why This Matters at IPO

Public-market investors price companies on revenue multiples. A company reporting gross revenue from hyperscaler resales shows a higher top line and a lower gross margin than an economically identical company reporting net. Both are technically permissible — provided the principal-agent determination is defensible. But they produce incomparable ARR figures and incomparable revenue multiples.

If Anthropic's $19B is actually closer to $12–13B on a net basis, and OpenAI's $25B is already net — the gap between these two companies looks very different than the headline numbers suggest.

Both companies are publicly preparing for IPO. Anthropic retained Wilson Sonsini in late 2025 for IPO advisory work. OpenAI is targeting as early as Q4 2026 and hired a Chief Accounting Officer in January. The S-1 filings will force explicit accounting policy disclosures. Restatement or reconciliation may follow if the SEC decides the principal-agent determination doesn't hold.

The Public Has a Right to Know This Now

The press has been remarkably incurious about this gap. Reporters write "Anthropic hits $19B ARR" and "OpenAI at $25B" in consecutive sentences as if the comparison means something.

It doesn't — not yet. Not until both companies are forced to stand in front of the SEC and explain, under oath, why they're measuring the same business relationship with different rulers.

Investors are already asking. The public should be too. Source: Forbes