Anthropic overtakes OpenAI in business customer share, Ramp data shows

Anthropic surpassed OpenAI in verified business customer adoption for the first time in May 2026, according to Ramp’s AI Index, signaling a shift in enterprise spending toward the Claude maker. Ramp said 34.4% of participating businesses paid for Anthropic services, compared with 32.3% for OpenAI. The index is based on expense data from more than 50,000 Ramp clients, though it may not fully represent the broader AI market. Anthropic’s share rose from 9% in May 2025, while OpenAI’s share fell 1 percentage point over the same period, Ramp said. Overall business adoption of AI products increased 9 percentage points. Ramp economist Ara Kharazian said Anthropic gained early traction with technical customers in finance, technology and professional services before expanding through products such as Cowork.