Why this is noise: The Ramp index measures paid adoption among Ramp's own client base, not the broader market. A 2.1 percentage point lead at one fintech's customers does not confirm a durable competitive shift, and Ramp's own economist flags the advantage may not hold.
Key Takeaways
- 34.4% of Ramp-tracked businesses now pay for Anthropic, ahead of OpenAI at 32.3%, the first time Anthropic has held the top position
- Anthropic’s paid adoption rose 26 percentage points in 12 months, from 9% in May 2025, while OpenAI’s share fell 1% over the same period
- Sample size of 50,000+ businesses gives the index credibility, but it reflects only companies using Ramp’s corporate card and bill pay platform
Anthropic has overtaken OpenAI in paid business adoption for the first time, according to the May edition of the Ramp AI Index, which tracks corporate spending across more than 50,000 American companies.
The index, compiled from Ramp clients’ expense data, shows 34.4% of participating businesses paying for Anthropic services against 32.3% for OpenAI. It is the first month Anthropic has held the leading position since the index launched.
The shift is the product of a sustained 12-month run. In May 2025, only 9% of businesses in the sample were paying for Anthropic products. That figure climbed 26 percentage points over the following year, while OpenAI’s share slipped by 1% and overall business AI adoption rose 9%.
Ramp economist Ara Kharazian attributed Anthropic’s rise to a deliberate sequencing strategy. “What Anthropic did worked really well,” Kharazian told TechCrunch, “which was — start with a very technical customer base, focus on their needs, really succeed in execution and then start broadening out through tools like Cowork.”
The Ramp data is not the only signal pointing in Anthropic’s direction. On OpenRouter’s model leaderboard, which draws from a separate user base, OpenAI last ranked above Anthropic in December 2025. The convergence across two independent datasets gives the trend more weight than either source alone.
“Anthropic has already been in the lead amongst the high adoption groups like finance, tech, professional services. It’s across the other firms where OpenAI still has a lead, but that has been shrinking over the past couple of months.” — Ara Kharazian, Lead Economist, Ramp
Kharazian is publicly skeptical the lead will hold, citing three underrated risks facing Anthropic in a post on the Ramp Economics Lab blog. He did not name the risks in his TechCrunch comments, and the full analysis requires reading the index directly.
The index carries a built-in blind spot: it captures only paid transactions through Ramp’s platform and misses businesses using free tiers, personal accounts, or rival expense tools. Actual adoption rates across the full market are likely higher for both companies, and the relative gap could look different on a broader sample.
The Ramp AI Index measures paid adoption only. Companies using free AI tiers or employee personal accounts are not counted, meaning the index likely understates total adoption for all vendors.
What the numbers cannot settle is whether Anthropic’s lead reflects product preference, enterprise sales execution, or pricing strategy, and whether OpenAI’s product investments will reverse the trend before the gap widens further. For professionals navigating these shifts, Relve sits at the intelligence layer between the AI industry and the decisions that matter, tracking how competitive dynamics like this one translate into real operational change.
