Anthropic overtakes OpenAI in business customer adoption

For the first time, Anthropic has surpassed OpenAI in verified business customer adoption, according to this month’s AI Index from the fintech firm Ramp. The index, compiled from the expense data of Ramp’s clients, shows that 34.4% of participating businesses are paying for Anthropic services. In comparison, 32.3% of participating businesses are paying for OpenAI services, marking the first time Anthropic has held the top position in this dataset.

Because the index only represents companies that use Ramp, it is not a perfect proxy for the marketplace at large. However, the sample includes more than 50,000 companies, making it broad enough to carry weight and show a clear trend in corporate AI adoption over the past year. According to Ramp’s figures, the 12 months following May 2025 have been particularly transformative for Anthropic. The comparative growth statistics highlight this shift:

• Anthropic’s share of business customers climbed 26% over the 12-month period, rising from a baseline of a mere 9% in May 2025.
• OpenAI’s share of business customers declined by 1% over the same period.
• The overall share of businesses paying for some kind of AI product increased by 9%.

This general trend is also visible on other platforms. On the leaderboard of OpenRouter, an AI model routing platform that samples a different portion of users, OpenAI last ranked above Anthropic in December 2025, indicating that Anthropic’s momentum is not isolated to a single dataset.

According to Ara Kharazian, an economist at Ramp, Anthropic has already been in the lead amongst high-adoption groups like finance, tech, and professional services. While OpenAI still holds a lead across other firms, Kharazian noted that this lead has been shrinking over the past couple of months. He stated that Anthropic’s approach worked really well, “which was — start with a very technical customer base, focus on their needs, really succeed in execution and then start broadening out through tools like Cowork.”

Why it matters

This shift in verified business customer adoption signals that Anthropic’s strategy of targeting technical users is successfully translating into broader corporate market share. By capturing high-adoption sectors first, the company is now challenging OpenAI’s long-standing dominance across the wider business landscape.