Anthropic overtakes OpenAI in verified business customers for first time
Analysis of expense data from over 50,000 companies shows the AI lab has surpassed OpenAI, marking a significant pivot in enterprise adoption trends.
For the first time, Anthropic has recorded more verified business customers than OpenAI, according to the May AI Index compiled by fintech firm Ramp. Data derived from the expense records of over 50,000 companies indicates that 34.4% of Ramp’s clients are currently paying for Anthropic services, compared to 32.3% for OpenAI. This milestone marks a decisive shift in the competitive landscape between the two leading artificial intelligence laboratories.
The surge in Anthropic’s market share represents a substantial acceleration from the previous year. In May 2025, only 9% of businesses were paying for Anthropic products. Over the following 12 months, that figure climbed by 26 percentage points. In contrast, OpenAI’s share has declined by 1% over the same period, narrowing the gap between the two firms and resulting in Anthropic’s current lead.
Ramp economist Ara Kharazian attributed the shift to a deliberate strategic approach by Anthropic. He noted that the company initially targeted a technical customer base, focusing heavily on execution and specific needs before broadening its appeal. This strategy has since expanded through tools such as Cowork, allowing the firm to penetrate sectors beyond its initial core.
While OpenAI retains a lead in broader firm categories, that advantage has been shrinking over recent months. Kharazian observed that Anthropic had already been leading in high-adoption groups, including finance, technology, and professional services. The trend is corroborated by data from OpenRouter’s leaderboard, where OpenAI last ranked above Anthropic in December 2025.
The broader industry context also shows growth, with the overall share of businesses using some form of AI product increasing by 9% over the past 12 months. However, analysts caution that the data represents only companies utilising Ramp, meaning it may not be a perfect proxy for the entire marketplace. Despite this limitation, the sample size of more than 50,000 companies provides a broad and diverse view of current enterprise spending habits.
