New data from corporate card provider Ramp suggests OpenAI is starting to claw back ground from Anthropic among US business customers, after losing the lead in May 2026. The figures matter because both companies remain private ahead of expected IPOs, making third-party spending data one of the few available proxies for how their commercial businesses are actually performing, and the shifting numbers suggest neither firm has secured a durable hold on enterprise customers.

Anthropic overtook OpenAI in May with 41% of Ramp's paying business users to OpenAI's 39%, and by July had extended that to nearly 44% versus almost 40%. However, Ramp's economist Ara Kharazian noted OpenAI is growing faster in the current quarter to date, crediting improved developer take-up of GPT-5.6 Sol, while Anthropic's higher-end Fable 5 tier reportedly disappointed on adoption amid its cost and a 30-day data retention requirement. The data, covering more than 70,000 mostly tech-leaning US businesses and billions in spending, excludes large enterprises using other providers such as American Express, and shows the overall paid-AI market growing too, with adoption among Ramp customers rising from just over 50% in March to nearly 56% by July.