Anthropic overtakes OpenAI in business customers for first time, per Ramp data

Anthropic has surpassed OpenAI in verified business customers for the first time, according to the latest AI Index from fintech firm Ramp. The data, drawn from expense records of over 50,000 companies, shows 34.4% of businesses paying for Anthropic services, while 32.3% pay for OpenAI. This marks a significant shift: in May 2025, only 9% of businesses used Anthropic, but that figure ballooned to 26% within 12 months. Meanwhile, OpenAI's share declined by 1% over the same period. Ramp economist Ara Kharazian noted that Anthropic has long led among high-adoption sectors like finance, tech, and professional services, but is now gaining ground across other industries, eroding OpenAI's previously dominant position. The trend is not isolated to Ramp's data: on OpenRouter, a different sample of users, OpenAI last held the top spot in December 2025.

Although Ramp's index is not a perfect market proxy, the sample size and diversity lend credibility to the findings. Kharazian warned that the lead may not be permanent, but he credited Anthropic's strategy: starting with a technical customer base, excelling in execution, and then broadening with tools like Cowork. The overall AI market is growing, with the share of businesses using any AI product increasing by 9% over the past year. This shift signals that business customers are increasingly willing to evaluate and switch AI providers, challenging OpenAI's long-held market dominance.