OpenAI Is Catching Up to Anthropic in the Battle for Business Customers

OpenAI is closing the gap with Anthropic among US business users, according to spending data from Ramp released on August 20, 2026. Ramp, a company that helps businesses manage corporate cards and expenses, reports that OpenAI's share of its paying business customers has been climbing in the third quarter of 2026, after Anthropic pulled ahead earlier in the year.

Anthropic first overtook OpenAI in May 2026, reaching 41% of Ramp's paying business users versus OpenAI's 39%. By July 2026, Anthropic held nearly 44% compared to OpenAI's nearly 40%. But Ramp economist Ara Kharazian says OpenAI is currently growing faster than Anthropic among Ramp's business customers so far in Q3 2026. TechCrunch

Ramp's data covers more than 70,000 American businesses. The company declined to share actual dollar amounts, only percentages. Ramp's customers tend to be tech companies, since its card is popular in Silicon Valley, and the data leaves out large corporations that use other expense tools like American Express.

The rivalry between the two companies has shifted a lot over the past year. In April 2025, OpenAI held roughly 32% of business AI adoption on Ramp's platform, while Anthropic sat at under 8%. VentureBeat Separately, Menlo Ventures reported that Anthropic tripled its enterprise market share to 40%, up from 12% in 2023, while OpenAI fell from 50% to 27% and Google reached 21%. LinkedIn/Menlo Ventures

Kharazian posted on X that OpenAI's latest model, GPT-5.6 Sol, is increasingly the choice for developers. Meanwhile, Anthropic's model called Fable 5 disappointed in adoption because of its price and data retention rules imposed by regulators. Anthropic warned Fable users that it must keep their data for 30 days.

The overall market is growing too. The percentage of Ramp customers that pay for AI topped 50% in March 2026 and reached nearly 56% by July 2026. Enterprise customers, meaning large organizations, account for roughly 40% of OpenAI's business and 80% of Anthropic's business, according to executives. CNBC

Anthropic's annual revenue run rate, a way of estimating yearly revenue based on current monthly performance, topped $65 billion by the end of July 2026, up from about $47 billion at the end of 2025. Reuters OpenAI says its enterprise product has more than 5 million business users and counts SoftBank, Target, and Lowe's as customers. TechCrunch

The broader context here is that data from a single expense platform can only tell us so much. Ramp's customers lean toward smaller, tech-focused companies, and the data excludes the largest corporations that route expenses through American Express or other established providers. The percentages show momentum within Ramp's group of customers, not the full enterprise AI market. Still, spending data is a stronger signal than surveys where companies self-report their usage, because it reflects actual money spent month after month.

Kharazian's commentary on X adds another layer worth considering. If OpenAI's GPT-5.6 Sol is winning developers while Anthropic's Fable 5 struggles with higher prices and a mandatory 30-day data retention rule, the factors driving the shift are specific and product-based, not about brand loyalty. A 30-day data retention requirement, imposed by regulators and disclosed to users, is the kind of compliance burden that corporate buying teams take seriously, especially in industries that are heavily regulated. The fact that a model's data rules can noticeably affect how fast it gets adopted tells us the market is growing up, moving beyond simply comparing which AI is smartest to evaluating which one meets the practical and legal requirements of large organizations.

Anthropic's heavy reliance on enterprise customers, with 80% of its business from that group versus OpenAI's 40%, has two sides. It means Anthropic has landed valuable large accounts, but it also means its revenue is more vulnerable if a single compliance problem or pricing mistake causes those customers to leave. OpenAI's more balanced mix of everyday consumers and enterprise customers may give it more flexibility to adjust its enterprise strategy without the same risk.

The geographic picture is also changing. According to Anthropic's own Economic Index report, the share of per-person usage going to the top five US states decreased from 30% to 24% between August 2025 and February 2026, suggesting AI use is spreading beyond early concentrations on the coasts. Anthropic

What the Ramp data ultimately captures is a market that is both growing and reshuffling at the same time. More than half of Ramp's business customers now pay for AI. The question of which provider leads on any given platform in any given month is becoming less a story of one winner taking everything and more a matter of which company shipped the better model, at the better price, with the more acceptable data rules in that particular quarter.