Anthropic now has more business customers than OpenAI, according to Ramp data

For the first time, Anthropic has surpassed OpenAI in business customer share according to Ramp's AI Index, which tracks expense data from over 50,000 companies. As of May 2026, 34.4% of Ramp's client businesses pay for Anthropic services versus 32.3% for OpenAI. Anthropic's share grew 26% over the past 12 months (from 9% in May 2025), while OpenAI's declined by 1%. The trend is corroborated by OpenRouter's leaderboard, where OpenAI last ranked above Anthropic in December 2025. Ramp's economist attributes Anthropic's rise to a deliberate strategy of targeting technical customers first before broadening its reach.