There seem to be plenty of data-points emerging that Anthropic is quite close to going past OpenAI, at least in enterprise adoption.
The latest comes from the Ramp AI Index, which tracks corporate card and invoice-based payments across more than 50,000 US businesses. In March, overall business AI adoption crossed 50% for the first time — reaching 50.4%, up from 35% a year ago. Half of US businesses on Ramp now pay for AI.
Within that broader surge, Anthropic’s numbers stand out. Its share of paying businesses jumped from 24.4% to 30.6% in a single month — a 6.3 percentage-point gain, surpassing even its own record from the prior month. OpenAI currently sits at 35.2%. The gap, which was 11 points as recently as February, has narrowed to 4.6 points. At this pace, says Ramp economist Ara Kharazian, Anthropic will overtake OpenAI within the next two months.
Already Ahead Where It Matters
The more telling finding is where Anthropic is already leading. It holds the top position in three sectors — information (software), finance, and professional services — which happen to be the three highest-adoption sectors overall. Among VC-backed companies, which have an 80% AI adoption rate versus 45% for everyone else, Anthropic (66%) already leads OpenAI (59%).
This follows a pattern that Ramp’s data has shown: the more mature an industry is in AI adoption, the more it tends to prefer Anthropic. The implication is directional. What sophisticated early adopters do today, the broader market tends to do a few months later.
Shrugging Off Headwinds
What makes Anthropic’s March surge notable is the context in which it happened. Last month, the Department of Defense designated Anthropic a security risk — a designation a judge has since temporarily blocked, and one that reports suggest the Pentagon is effectively working around. Businesses, apparently, didn’t flinch. Adoption accelerated anyway.
Funding as a Predictor
Ramp’s data points to an unexpected driver of AI adoption: who funded you. VC-backed companies adopt AI at an 80% rate; PE-backed at 64%; everyone else at 45%. The funding source predicts AI adoption more reliably than industry. VCs are functioning as a transmission mechanism — through portfolio-wide deals, top-down directives, and a cultural expectation that founders are using the latest tools.
Among those VC-backed firms — the most sophisticated buyers — Anthropic is already the leading AI vendor. That’s the cohort the rest of the market typically follows.
The Bigger Picture
This is consistent with a broader trend. Menlo Ventures data has shown Anthropic leading the enterprise LLM API market with a 40% share versus OpenAI’s 27%. Ramp’s own historical data shows Anthropic going from capturing roughly 10% of combined OpenAI-Anthropic business subscription spend in early 2025 to over 65% by February 2026.
Anthropic’s revenue run-rate has now hit $30 billion — up from $9 billion at the end of 2025 — growing at roughly 10x annually versus OpenAI’s 3x. The company recently raised $30 billion at a $380 billion valuation, with the number of customers spending over $1 million annually surging from a dozen two years ago to over 500 today.
OpenAI retains meaningful advantages — ChatGPT’s consumer brand, deep Microsoft integration, and a mature enterprise sales operation. But Ramp’s data now draws a clear trajectory: if the gap between the two companies continues closing at the current pace, the crossover in business customer count is a question of when, not if.