Enterprise AI Hardened Into a Two-Vendor Market, Ramp's Card Data Shows
Ramp has Anthropic at 44% of paying business AI customers to OpenAI's 40% in July, with OpenAI growing faster in Q3. Nearly 56% of Ramp's customers pay for AI, up from 50% in March.
TL;DR
- Ramp's card data across 70,000+ businesses put Anthropic at 44% of paying business AI customers to OpenAI's 40% in July, with OpenAI growing faster in Q3.
- Enterprise AI has settled into a two-vendor category, though Ramp counts customers rather than dollars and misses the largest enterprises.
- By October, Ramp's index had Anthropic at 44.8% and OpenAI flat at 40.6%, a 4.2-point gap, more than twice May's two points.
on AI Market Share
Enterprise AI has a market structure now, and it took a corporate card company to reveal it. Ramp's spend data across more than 70,000 American businesses shows Anthropic holding roughly 44% of paying business AI customers to OpenAI's 40% as of July, a lead Anthropic has kept since May, when the split stood at 41% to 39%. Ramp economist Ara Kharazian adds the wrinkle that matters: OpenAI is growing faster among these buyers in Q3 to date.
The caveats travel with the data. Ramp sees its own customers, which excludes the largest enterprises running American Express-tier programs, skews toward tech, and captures share of customers rather than share of dollars; Ramp declined to disclose amounts.
As a census it's partial. As a market-structure reading it's the best public instrument anyone has, and what it shows is a two-vendor category with an incumbent, a challenger, and a growth-rate argument between them.
That's a procurement fact, not a horse-race fact.
The category matured faster than the buying process did
Most companies still buy AI the way they bought it in 2024: a tool decision, made by whoever felt the pain first, renewed by inertia.
Two other numbers in the Ramp data say that era is over. Nearly 56% of Ramp's customers now pay for AI services, up from 50% in March, so the spend is mainstream. And both vendors shipped enterprise data-control features in the same week, Anthropic moving customer data retention into client clouds while OpenAI previewed Private Safety Processing with Databricks and Microsoft.
Vendors ship governance features when procurement teams start asking governance questions; the roadmaps are telling you who's now in the room. The specifics also happen to be negotiating material: Anthropic's move puts customer data retention inside the client's own cloud, OpenAI's Private Safety Processing runs with Databricks and Microsoft, and either program is the kind of concession you cite to the other vendor by name.
A stable two-vendor market with mainstream penetration and converging enterprise feature sets is a category that rewards being negotiated, and punishes being defaulted into.
The nearest comparison is the cloud wars. AWS and Azure settled into a stable two-vendor market where companies that kept workloads genuinely portable got real concessions out of it. Companies that technically had a second vendor but couldn't actually move workloads there didn't have much leverage at all.
Right now, switching between AI vendors is cheaper than that cloud comparison suggests, mostly because the interfaces are converging on the same protocols, and the switching cost is closer to re-testing prompts than re-platforming infrastructure.
But that advantage won't last forever. As companies build more agent workflows around vendor-specific features, that portability will get harder to maintain.
Anthropic still leads 44.8% to 40.6%, and the gap widened
Both labs shipped enterprise data-control features in the same week, Anthropic moving customer data retention into client clouds and OpenAI previewing Private Safety Processing with Databricks and Microsoft, so the split matters to every buyer renewing with either one. Kharazian's growth-rate reading came with a month left in Q3, against a gap that was two points in May. By October the gap was more than twice that.
In October, 56.8% of businesses on Ramp paid for AI, Ramp's index shows. Anthropic reached 44.8% of businesses and OpenAI held at 40.6%, flat from September, a gap of 4.2 points.
Ramp's next monthly AI Index will show whether OpenAI, flat at 40.6% of businesses in October, resumes the faster growth Kharazian saw in the third quarter.
