OpenAI narrows gap with Anthropic among Ramp’s business customers

For most of the past year, the story in enterprise AI has been Anthropic’s meteoric rise. The company quadrupled its share of US business adoption from roughly 9% to over 34% in about twelve months, eventually overtaking OpenAI among Ramp’s tracked corporate customers. But the latest data suggests OpenAI isn’t content playing second fiddle. As of mid-August 2026, OpenAI has begun closing the gap with Anthropic in quarter-over-quarter enterprise growth, posting a QoQ growth rate of 82 compared to Anthropic’s 76. The numbers come from Ramp’s AI Index, which tracks actual payment transactions across its corporate card network rather than relying on surveys or self-reported data. The numbers behind the shift Rewind to April 2026, and Anthropic hit a milestone that would have seemed absurd a year earlier. Its products were being used by 34.4% of Ramp’s US business customers, edging past OpenAI’s 32.3%. For context, Anthropic sat at just 9% adoption in May 2025. By July 2026, Anthropic had extended its lead further. Adoption climbed to 43.5% among tracked businesses, while OpenAI held 39.7%. Anthropic’s strength was concentrated in high-adoption verticals like finance and technology. But...