Exclusive-Anthropic IPO prospectus lays bare deep dependence on Big Tech partners

By Echo Wang and Krystal Hu

Sept 29 (Reuters) - Anthropic's IPO prospectus shows how much it depends on a small group of customers and tech giants, highlighting key risks for the AI developer as it asks investors to back its ambitious, capital-intensive plan that it says will transform the global economy.

The company routed 47% of its sales to customers last year through cloud partners Amazon and Alphabet's Google, according to a copy of its confidential IPO filing seen by Reuters. Those two companies, which are supercharging the AI developer's distribution and collecting customer bills on its behalf, are also big Anthropic investors, critical suppliers of computing power and direct rivals in AI. 

Amazon declined to comment. Anthropic and Alphabet did not respond to requests seeking comment.

The filing offers a rare look inside a business that barely existed several years ago but is growing at breakneck speed due to its role as a key developer of large-language AI models. Anthropic is seeking a valuation of about $2 trillion and has plans to spend hundreds of billions in the coming years to accelerate its growth.

Revenue surged 12-fold in 2025 to nearly $4.6 billion, while operating losses more than doubled to top $8 billion, Reuters reported exclusively on Monday. The US accounted for nearly two-thirds of total sales.

About $3.8 billion in Anthropic's revenue came from customers paying based on how much they use the company's Claude AI system, while subscription revenue came to $789 million. Anthropic said it expects consumption-based revenue to account for "the substantial majority" of its revenue for the foreseeable future.

REVENUE CONCENTRATION GROWS

Sales through the cloud marketplaces totaled about $2.16 billion, or 47% of Anthropic's annual revenue in 2025, the filing shows.

The company paid roughly $351 million back to the platforms in distribution fees, according to a Reuters analysis, suggesting the cloud providers collected some 16 cents for every dollar of those sales. Anthropic reports channel partner fees within the "sales, marketing, and partnerships" operating expense line item on its financial statements. 

The fees are one strand of an increasingly circular financial relationship. Amazon and Google have invested tens of billions of dollars in Anthropic, while the AI developer has made enormous commitments to buy computing capacity. 

At the end of 2025, Anthropic had $54.6 billion in non-cancellable hosting and computing commitments. By early 2026, its total long-term commitments exceeded $417 billion, covering 3.5 gigawatts of dedicated computing capacity.

Anthropic, in its prospectus, framed these relationships as an advantage. It said that by offering its Claude AI model through Amazon, Google and Microsoft's cloud platforms, it can tap their vast sales networks and reach customers already using their services, accelerating "market penetration at a scale we believe would be difficult for any single organization to directly replicate."

But the company also acknowledged that its reliance on a limited number of partners and suppliers "creates complex dynamics that could give rise to conflicts of interest and adversely affect our access to compute." 

The company signed a cloud computing deal with Microsoft in November. 

The cloud providers also gain visibility into Anthropic's pricing and commercial terms, which could influence their decisions on compute allocation and how aggressively they sell its products, the filing said. The cloud companies are also Anthropic's customers, it noted. 

Anthropic's dependence on Amazon and Google has grown as its revenue soared. Sales through the two companies rose from 11% of revenue in 2023 to 32% in 2024, and nearly half last year. 

The company's cash collection is also increasingly funneled through these third parties, which were responsible for collecting 60% of the $909 million in customer bills outstanding at the end of 2025, up from 42% in 2024. Anthropic warned that disputes or delays in that pipeline could hurt cash flow even though it contracts directly with the customers. 

Its customer base is also concentrated, as two unnamed customers each generated 12% of revenue last year. Anthropic warned that many of its biggest customers are not bound by long-term contracts and could reduce or halt spending.

The cloud relationships have also complicated financial comparisons with rival OpenAI.

Anthropic books the full value of marketplace contracts — sales agreements where customers buy access to Claude through a cloud provider's marketplace — as revenue because it sets prices and delivers the service, while recording the platforms' cut as a marketing cost.

OpenAI has told investors and employees this approach inflates Anthropic's reported revenue by billions of dollars, Reuters reported in June. Anthropic told Reuters then that it follows established accounting practices, recognizing gross revenue because it is the “principal” in the transaction. 

(Reporting by Echo Wang in New York and Krystal Hu in San Francisco; Additional reporting by Stephen Nellis in San Francisco; Editing by Sayantani Ghosh and David Gaffen)