Anthropic Tops OpenAI in Business Adoption for First Time
Ramp's May 2026 AI Index shows 34.4% of businesses now pay for Anthropic, edging out OpenAI at 32.3% - the first time Anthropic has led in enterprise adoption.
6 min read
34.4%. That's the share of businesses that paid for Anthropic products in April 2026, according to Ramp's monthly AI Index - and it's the number that knocked OpenAI out of the top spot for the first time.
TL;DR
- 34.4% of businesses surveyed by Ramp now pay for Anthropic, vs. 32.3% for OpenAI - the first time Anthropic holds the lead
- A year ago, Anthropic's business adoption sat at just 9% - a 26-point climb in 12 months
- OpenAI's share grew only 0.3% over the same period and fell 2.9 points in April alone
- Overall AI product adoption across businesses reached 50.6% - up from ~41% a year ago
- The shift is confirmed by a second dataset: OpenRouter's leaderboard shows OpenAI last ranked above Anthropic in December 2025
Ramp's index draws on business spend data from more than 50,000 companies - corporate card and invoice-based payments processed through the platform. It's not a census of the entire market, but it's large enough and broad enough to carry real weight.
What the Numbers Say
Anthropic's Twelve-Month Climb
In May 2025, only 9% of businesses on Ramp's platform were paying for Anthropic products. By April 2026, that figure had reached 34.4% - a 26-point increase in 12 months. That kind of growth in enterprise software adoption is rare. For context, it means Anthropic nearly quadrupled its business customer base in a single year while the broader AI market grew by just 9 points.
The explanation that Ramp's economist Ara Kharazian offers is a deliberate sequencing strategy.
"Targeted strategy of hitting technical customers in finance, technology, and professional services before broadening outward," Kharazian wrote in the May AI Index.
That strategy worked. Technical teams at finance and professional services firms adopted Claude for coding, data analysis, and document review. Word spread within those industries. And Claude Code - Anthropic's agentic coding product - gave developers a concrete reason to pay for Anthropic at work rather than using personal accounts. A separate analysis found that approximately 4% of all public GitHub commits worldwide were being authored by Claude Code as of April 2026, a figure that signals just how deeply it has embedded into developer workflows.
OpenAI's Flat Year
OpenAI's numbers look very different. Its business adoption share grew by only 0.3% over the same 12-month period. In April alone, it fell 2.9 points - from roughly 35% to 32.3%. That's a significant monthly drop for a company that still controls the consumer market and reported around $24 billion in annualized revenue earlier this year.
The Ramp data doesn't explain why OpenAI lost share, but the timing offers clues. April 2026 was also the month when Anthropic published its ARR surpassing OpenAI's at $30 billion - a milestone that made enterprise procurement teams pay closer attention. Price competition from open-source model providers also deepened during this period, which may have pushed some buyers toward Anthropic's Claude offerings on cost-efficiency grounds.
| Provider | Business Adoption Share | Month-over-Month Change | 12-Month Change |
|---|---|---|---|
| Anthropic | 34.4% | +3.8 pts | +26 pts |
| OpenAI | 32.3% | -2.9 pts | +0.3 pts |
| ~10% | n/a | n/a | |
| Overall AI adoption | 50.6% | +0.2 pts | +9 pts |
The Small Business Push
Anthropic isn't stopping with enterprise. The company recently launched Claude for Small Business - a product tier aimed at owners rather than developers. It includes bookkeeping tools, business insights generators, and ad campaign builders, with integrations built for QuickBooks, Canva, DocuSign, HubSpot, and PayPal. The launch also includes a ten-city promotional tour starting in Chicago, offering free AI training workshops to 100 small business leaders per stop.
This is the "broadening outward" that Kharazian described. Whether small businesses convert at the same rate as technical enterprise teams is an open question. Small businesses churn faster and have lower willingness to pay for API-level products.
Anthropic's share of business AI spending jumped from 9% to 34.4% in twelve months according to Ramp's AI Index, overtaking OpenAI for the first time.
Source: ramp.com
What the Numbers Don't Say
Ramp's index measures businesses that pay for AI products through Ramp. It doesn't capture companies that pay through other expense systems, direct invoice relationships, or enterprise agreements negotiated at the CFO level. Large-cap enterprise deals often bypass standard corporate card flows completely - which means the actual split at the top of the market may look quite different.
OpenAI also remains the dominant consumer brand by a wide margin. ChatGPT has hundreds of millions of users. Ramp's index measures business payment adoption, not total usage or total revenue. OpenAI reportedly created around $24 billion in annualized revenue before Anthropic's recent ARR milestone - and those revenue figures cover a different population than Ramp's sample.
Kharazian himself wrote in the report that its findings "should not be construed to suggest Anthropic is the definitive leader." He flagged three headwinds: pricing incentives that don't align well with enterprise buyers (Anthropic profits when customers use more tokens, which can push users toward its pricier models), recent service quality issues, and product changes that have raised costs for some customers.
"Anthropic's incentives are misaligned with those of business customers," Kharazian wrote, noting the company profits when businesses purchase more tokens - potentially driving "users to more expensive models."
OpenRouter's data adds independent corroboration that the shift is real, not a Ramp-specific artifact. On its leaderboard - which samples a different user population - OpenAI last ranked above Anthropic in December 2025. The two datasets point in the same direction.
Anthropic's Claude for Small Business offers integrations with QuickBooks, Canva, and HubSpot as the company extends its reach beyond technical enterprise teams.
Source: anthropic.com
The Valuation Signal
There's a financial dimension to this market shift that's worth noting. Anthropic is currently seeking a new funding round at approximately $950 billion valuation - above OpenAI's March 2025 valuation of $854 billion. If Ramp's data is any guide to what investors are seeing, the growth arc makes the ask look defensible, even if the absolute number raises eyebrows.
The company has already raised substantial capital and counts Amazon and Google among its major backers. A $950 billion valuation would make it one of the most valuable private companies ever. Whether that's justified depends heavily on how durable this business adoption lead turns out to be.
So What?
The Ramp data is a signal, not a verdict. One month of business adoption share doesn't determine the outcome of a multi-year enterprise software competition. OpenAI is redesigning its enterprise products, pushing hard on Codex for developers, and still commands a consumer audience that dwarfs Anthropic's reach. The competitive pressure from open-source providers is hitting both companies.
But Anthropic's climb from 9% to 34.4% in a single year isn't noise. It reflects deliberate product decisions, a clear sequencing strategy, and enterprise teams actively choosing Claude over GPT for production workloads. The December 2025 crossover on OpenRouter and the April 2026 crossover on Ramp don't cancel each other - they reinforce each other.
The first lead is real. Whether Anthropic can hold it is a separate question.
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