OpenAI and Anthropic before the IPO: Different balance sheets make comparison difficult

Anthropic and OpenAI are both growing fast, but they report revenue very differently, The Information reports. OpenAI's annualized revenue is around $25 billion; Anthropic's is $19 billion. Both calculate this similarly: four weeks of revenue times 13, with Anthropic adding monthly subscriptions times 12.

The key difference is how they handle cloud partners. OpenAI gives 20 percent of revenue to Microsoft and reports the number before that deduction. For Azure cloud sales, it only counts its 20 percent cut. Anthropic does the opposite: It books all cloud sales through AWS, Microsoft, and Google as its own revenue, listing the providers' shares as sales and marketing costs. Anthropic considers itself the primary provider, while OpenAI treats Microsoft as the primary provider for Azure.

Both follow US accounting rules (GAAP), but their numbers are difficult to compare. Anthropic's revenue likely looks higher on paper than it would under the same method. That matters as both companies head toward an IPO.