Anthropic has overtaken OpenAI in a critical business metric: new enterprise customer spending. According to Ramp's March 2026 AI Index published on March 18, Anthropic now captures over 73% of all spending among companies purchasing AI tools for the first time. The shift has been swift - as recently as early December 2025, OpenAI held a 60/40 advantage, and the split was 50/50 just ten weeks before the latest data.
The data point matters because new customer acquisition is a leading indicator of where the enterprise market is heading. While OpenAI still leads in total annualized revenue at roughly $25 billion compared to Anthropic's $19 billion, Anthropic's growth rate tells a different story. The company hit $19 billion in annualized revenue in March 2026, up from $14 billion in February and $9 billion at the end of 2025.
Epoch AI analysis suggests that if current trajectories hold, Anthropic could surpass OpenAI in total annualized revenue by mid-2026. The enterprise preference for Claude appears driven by its strong performance on coding and analytical tasks, which are the primary use cases for business buyers.
The revenue race between the two companies has intensified at a time when both are navigating significant external pressures - OpenAI with its transition to a for-profit structure, and Anthropic with its ongoing legal challenges.