Anthropic held nearly 44% of Ramp’s paying business users in July, compared with nearly 40% for OpenAI, after taking the lead in May with 41% versus 39%. The figures cover more than 70,000 American businesses spending billions through Ramp’s corporate cards and bill-pay products, though the customer base skews toward technology companies and excludes enterprises using providers such as American Express. Ramp economist Ara Kharazian said OpenAI was growing faster than Anthropic among the segment in the third quarter to date. Ramp’s data also indicates that the overall market is expanding: the share of customers paying for AI rose above 50% in March and reached nearly 56% by July. The shifts suggest Anthropic’s lead is not permanent and that businesses may change providers as new models are released, raising questions about the stickiness of enterprise AI spending.