Reuters read Anthropic's confidential IPO prospectus. Nearly half of 2025 revenue ran through the two companies that fund it, power it, and compete with it. Who owns the customer?
Sriram Subramanian · CloudDon Field Notes · 30 September 2026
Anthropic's growth is real on every number Reuters has seen. But its reach is rented.
Reuters has read the confidential draft of Anthropic's IPO prospectus and published it in two parts. The first, on September 28, covered the income statement: revenue up 12-fold in 2025 to nearly $4.6 billion, an operating loss above $8 billion, and a net loss of about $42 billion. The second, on September 29, covered where the revenue comes from. That is the one worth reading twice.
None of this is public or audited yet. The S-1 is not on EDGAR, and SEC rules require it to go public at least 15 days before any roadshow. So treat what follows as a pre-filing read. I will grade it against the filing when it lands.
The loss is mostly accounting
The $42 billion headline needs a footnote. About $34 billion of it was an accounting charge reflecting a rise in the estimated value of financing that could convert into shares. The number to hold is the operating loss: more than $8 billion, with $7.33 billion of compute and infrastructure inside $12.65 billion of operating expenses.
2026 looks different. Bloomberg reports second-quarter revenue above $11.5 billion, against $4.73 billion in the first quarter, with positive adjusted operating income. The Financial Times reports gross margins above 80%, stated before training costs and before the revenue Anthropic shares with distribution partners such as Amazon. Hold on to that last exclusion.
Rented Reach
In 2025, $2.16 billion of Anthropic's revenue, 47% of the total, came through the Amazon and Google cloud marketplaces. In 2024 the share was 32%. In 2023 it was 11%.
The usual arc, in my experience, is to rent distribution early and buy it back with scale. Anthropic rented more as it grew. On my arithmetic from Reuters' figures, marketplace revenue rose roughly 17-fold in 2025 while the company grew 12-fold.
The landlords wear several hats. Amazon and Google sell Claude and collect the bills. They are major investors (Amazon alone has put in $8 billion and committed up to $25 billion more), they sell it compute, and they build competing models. The filing adds that they are Anthropic customers too. Anthropic's Series H in May included $15 billion of previously committed hyperscaler money, $5 billion of it from Amazon.
I am calling this Rented Reach: the share of a company's revenue that arrives through a channel owned by a party that also funds it, supplies it and competes with it. Anthropic's went 11%, 32%, 47%. And the 47% counts Amazon and Google only. Claude also sells through Microsoft's cloud, and whatever flows there sits inside the other 53%.
The rent is booked as marketing
Reuters calculates that the platforms kept about $351 million in 2025, roughly 16 cents on every marketplace dollar. Anthropic books the full sale as revenue, because it sets the price and delivers the service, and records the platforms' cut under sales, marketing and partnerships. OpenAI, which books only its share of certain partner sales, has told investors this inflates Anthropic's revenue by billions.
On 2025 numbers, the platforms' cut was about 7.6% of revenue: $351 million out of $4.6 billion. An Axios source familiar with Anthropic's financials put the net-basis hit at 6% to 10%. At today's run-rate scale, that range does run to billions of dollars. The accounting choice lifts the top line and moves the rent out of gross margin. It leaves the operating loss exactly where it was.
Run rate is the other trap. Anthropic's own chart put its run rate at about $9 billion at the end of 2025, against $4.6 billion recognized for the year. The gap has already produced errors in print: CNBC in August described 2025 as roughly $10 billion of revenue.
The landlords can read the ledger
The sharpest line in the reporting was written by Anthropic itself. The filing says the cloud providers gain visibility into its pricing and commercial terms, which could influence how they allocate compute and how hard they sell its products. It warns of conflicts of interest.
Cash runs through the same pipe. Amazon and Google collected 60% of the $909 million in customer bills outstanding at the end of 2025, up from 42% a year earlier. Two unnamed customers produced 12% of revenue each, and many of the largest customers have no long-term contracts. About 83% of revenue is usage-based, and Anthropic expects consumption to remain the substantial majority. That meter produced a 14-fold year-on-year quarter. It can also turn down with a configuration change.
The tenant's case
Anthropic's side is strong. The marketplaces give it sales reach it says no single company could build alone. Enterprise buyers prefer the route, because it draws down cloud commitments they already hold and cuts contracting and billing work. Gross booking as principal is established practice when the seller sets the price. And 16 cents on the dollar buys a global enterprise sales force Anthropic did not have to hire.
I accept most of it. The case holds for as long as the landlords' interests line up with the tenant's, and the filing is Anthropic's own admission that they may not.
What I expect, and when
I postulate that the cloud providers become Anthropic's main route to market. By the end of 2027, at least 60% of Anthropic's revenue in a reported period will come through AWS, Microsoft and Google. The clouds will own the customer.
The number may land a few points either side of sixty. The direction will not reverse.
Recommendation
If you buy Claude through AWS or Google Cloud, your payments, your capacity and Anthropic's pricing all pass through a company that also sells competing models. That is true even when your contract is with Anthropic. The 16-cent fee is the small part. The larger part is who controls the pipe. Know which of your AI spend runs through which cloud, and ask how your provider treats Claude against its own models.
This is the channel-side sequel to The AGI Era Has a Tollbooth. That piece priced the toll at the model layer. This one follows the rent.
The full analysis is in CIIB-006 for CloudDon subscribers: the source-tagged financials, the two-ledgers view of gross versus net and run rate versus recognized revenue, four dated predictions with a public scorecard, and recommendations for enterprise buyers, investors and founders building on Claude.