Anthropic vs OpenAI revenue: why gross vs net accounting makes the run-rate headlines hard to compare

For most of 2026, the race between Anthropic and OpenAI has been told through one number: annualized revenue, or "run-rate." On October 9, 2026, Bloomberg reported that the two companies don't calculate it the same way. According to summaries of Bloomberg's analysis, Anthropic counts the gross amount of certain sales made through cloud partners such as Amazon as its revenue, while OpenAI records only its share of certain partner sales, such as those through Microsoft. Bloomberg's verdict, as quoted in those summaries: the numbers are "not apples to apples."

The story landed a day after reports that OpenAI's run-rate was about $20 billion lower than the figure widely cited in late September, and that the gap came from accounting, not lost sales. This analysis explains what gross and net revenue mean, what each company has actually disclosed, and why the headline figures can't be lined up.

It is based on reporting by Bloomberg, the Financial Times, Reuters, CNBC, The Information and TechCrunch, the companies' own statements, and Deloitte's guidance on US revenue-recognition rules, checked October 12, 2026. Bloomberg's October 9 analysis is paywalled; we checked its opening paragraphs, syndicated by Bloomberg Government, and rely on attributed summaries for the rest.

The short version

• Gross vs net: if a company is the "principal" in a sale, it reports the full price as revenue and the partner's cut as a cost. If it is the "agent," it reports only what it keeps.
• Anthropic reportedly counts the gross value of some Claude sales through cloud marketplaces such as Amazon's.
• OpenAI reportedly counts only its share of some partner sales, including through Microsoft.
• The numbers: OpenAI told investors about $50 billion at the end of September (FT, The Information, CNBC). Anthropic reportedly passed $65 billion at the end of July (Bloomberg). The ~$70 billion OpenAI figure reported in late September came from investors restating OpenAI on Anthropic's basis, the FT reported.
• Bottom line: neither company discloses its partner splits, so you can't convert one figure into the other's basis.

What is gross vs net revenue?

Under US accounting rules (ASC 606), when a company sells something with another party involved, it has to decide whether it is the principal or the agent. Deloitte's guidance summarizes the test: if the company "controls the specified good or service before it is transferred to the customer," it is the principal and "recognizes revenue on a gross basis." If it doesn't, it is the agent and recognizes revenue on a net basis.

The rules list three indicators of control, none decisive on its own:

1. Primary responsibility for delivering the product.
2. Inventory risk, such as being stuck with unused capacity.
3. Pricing discretion, meaning who sets the price.

Here is a simple, purely illustrative example. A developer pays a cloud marketplace $100 for Claude usage, and the cloud provider keeps an unspecified share before passing the rest to Anthropic.

• Gross (principal): Anthropic reports $100 of revenue and records the cloud provider's share as a cost.
• Net (agent): Anthropic reports only the amount it receives.

Profit is the same either way. Revenue, and therefore growth rates, revenue multiples and market share, is not. The bigger the partner channel and the partner's cut, the bigger the gap.

One more wrinkle: run-rate is not an accounting measure at all. It is current revenue annualized, usually a recent month multiplied by 12. Companies choose how to calculate it, and neither Anthropic nor OpenAI publishes its method. The gross-vs-net question applies to it only to the extent the companies build it from the same revenue lines.

What the companies have disclosed

Neither company publishes audited run-rate figures. Here is what each has said itself, and what has been reported.

Last verified: October 12, 2026

The October 8 reports cleared up the late-September confusion. The FT reported that the earlier "nearly $70 billion" figure came from "attempts by OpenAI's own investors to produce a direct comparison" with Anthropic, according to a summary by The Next Web. A person familiar with the matter told CNBC that the $68 billion figure included gross revenue from partners. The Information reported that OpenAI hadn't disputed the higher numbers at the time.

So the ~$70 billion and ~$50 billion figures both describe OpenAI around the end of September. The difference is the method, not the business.

Where the cloud partners come in

Both companies sell through the big clouds, but the arrangements differ.

• Anthropic sells Claude directly and through Amazon Bedrock, Google Cloud's Vertex AI and Microsoft Foundry, and says it is the first frontier model on all three. Cloud marketplaces are a large channel. According to a Benzinga summary of Reuters' reporting on Anthropic's leaked IPO prospectus, about $2.16 billion, or 47%, of Anthropic's 2025 revenue came through cloud marketplace sales with Amazon and Google. That figure hasn't been confirmed by Anthropic, and the summary doesn't say how those sales were recognized.
• OpenAI has long sold through Microsoft. Under its restructured agreement of April 27, 2026, Microsoft "no longer pays OpenAI a revenue share," while OpenAI's payments to Microsoft continue through 2030 "at the same percentage but subject to a total cap," as our OpenAI explainer details. The Next Web, summarizing Bloomberg and The Information, reported that OpenAI's mid-August $40 billion figure included Azure revenue OpenAI had stopped receiving around April.

That last point shows how messy this gets: even OpenAI's own reported series may not be on one consistent basis across 2026.

Does this mean Anthropic is smaller than it looks?

Not necessarily, and the evidence doesn't support a precise answer.

• The direction is clear. If Anthropic reports some marketplace sales gross and OpenAI reports comparable sales net, Anthropic's headline figure is inflated relative to OpenAI's, by an amount that depends on how much of its revenue flows through partners and how big the partners' cut is.
• The size is unknown. Neither company has published its cloud partners' share of each sale. Without that, no outside analyst can restate one company on the other's basis.
• Gross can be correct accounting. If Anthropic controls the service (it runs the model, sets the price and is responsible for delivery), principal treatment may be appropriate under ASC 606. Whether it is depends on contract terms we haven't seen. Gross reporting isn't, on its own, an error or a trick. It just answers a different question from net.
• Run-rate and accounting revenue diverge. Reuters, which reviewed Anthropic's leaked prospectus, reported 2025 revenue of nearly $4.6 billion. Reuters, citing a person familiar with the matter, has put Anthropic's run-rate at about $9 billion at the end of 2025. Those figures aren't in conflict, because one is a full year's revenue and the other annualizes a fast-growing final month, but they show how far apart the two measures can be.

Researchers at Epoch AI, who track AI company revenue reports, now label OpenAI's ~$30 billion (July) and ~$50 billion (September) figures as net and the ~$40 billion and ~$70 billion figures as grossed up. They mark Anthropic's figures as "not stated."

Why it matters now

Both companies are moving toward public markets. Anthropic confidentially submitted a draft S-1 on June 1, 2026, and Bloomberg reported on October 8 that it could list as soon as November. OpenAI has pushed its IPO to 2027 at the earliest and is reportedly raising at least $30 billion at a $1.4 trillion pre-money valuation. A public prospectus has to state, in audited figures, whether partner sales are recognized gross or net. That will be the first authoritative answer.

Investors are already reacting to the uncertainty. On October 8, after the OpenAI reports, the Nasdaq 100 fell 1.4% and a chip-stock index dropped 3.4%, Bloomberg reported, with Oracle, Nvidia and CoreWeave among the decliners. Big compute contracts, the ones our gigawatt datacenter tracker follows, are priced against these revenue expectations.

How to read AI revenue headlines from here

1. Check who said it. A company statement, a figure "shared with investors" and an investor's own estimate are three different things.
2. Check the basis. Ask whether partner sales are counted gross or net. If the story doesn't say, assume figures from different companies aren't comparable.
3. Don't mix run-rate and revenue. Run-rate annualizes a recent period; annual revenue is what was actually booked.
4. Look for the denominator. Margins and compute costs matter more than the top line, a point our analysis of why token pricing isn't the story makes for API buyers.

What's confirmed, reported and uncertain

• Confirmed (company statements): OpenAI's $2 billion a month (March 31, 2026); Anthropic's run-rate over $47 billion (May 2026); the April 27, 2026 Microsoft–OpenAI terms.
• Confirmed (accounting standards): the principal-versus-agent test, as summarized by Deloitte.
• Reported: Bloomberg's gross-vs-net finding (via summaries); OpenAI's ~$50 billion end-of-September figure and $70 billion year-end forecast; Anthropic's $65 billion end-of-July figure; the FT's explanation of the ~$70 billion figure; Reuters' figures from Anthropic's leaked prospectus and its end-2025 run-rate of about $9 billion.
• Uncertain: the partners' share of each sale, how Anthropic's GAAP revenue treats marketplace sales, and whether either company's run-rate series is internally consistent across 2026.

Our Anthropic explainer has the company's self-reported run-rate history through May, and our funding news story sets out the late-September OpenAI reports. Both predate the October 8–9 reporting covered here.