Anthropic still leads business AI spend, but OpenAI closing gap

What happened: Ramp, the corporate card and spend-management firm, says Anthropic still leads OpenAI among the 70,000-plus US businesses it tracks, but OpenAI is closing in.

The numbers: Anthropic took the lead in May 2026 with 41% of businesses versus OpenAI's 39%. By July, Anthropic had grown to nearly 44%, but OpenAI had climbed to nearly 40%, its share rising again after May.

The context: Overall AI adoption among Ramp's customers is surging. The share paying for AI passed 50% in March and hit nearly 56% by July, according to the Ramp AI Index.

The catch: Anthropic's premium model, Fable 5, has captured a smaller slice of usage than OpenAI's cheaper GPT-5.6 Sol. That suggests businesses are reluctant to pay extra for small performance gains.

In their words: Ramp economist Ara Kharazian said "GPT-5.6 Sol is really good, increasingly the choice for developers."

Who's affected: Developers are the swing group. Their preference for GPT-5.6 Sol is a big driver of OpenAI's renewed momentum.

Why it matters: Anthropic reported a $65 billion run rate in July against OpenAI's roughly $40 billion, so Anthropic still leads on revenue. But the Ramp figures show the enterprise adoption race is tight, and price-performance, not raw capability, is what's deciding it.

What's next: Watch whether Anthropic responds on pricing, or whether OpenAI's cheaper model keeps eating into business share through the rest of 2026.