New data from Ramp, a corporate credit card and expense management company, indicates that OpenAI is gaining significant ground on Anthropic among U.S. businesses in Q3 2026. After losing the lead to Anthropic in May, OpenAI has posted an 82% quarter-over-quarter enterprise growth, outperforming Anthropic's 76% growth. This marks a dramatic reversal, as Anthropic held a substantial lead in enterprise market share as recently as late 2025, with Menlo Ventures pegging Anthropic at 40% of enterprise LLM spend compared to OpenAI's 27%.
The key catalyst for OpenAI's resurgence is its GPT-5.6 Sol model, launched on June 26, which has been well-received by developers and demonstrated strong performance on coding benchmarks like Terminal-Bench 2.1 (scoring 88.8 to 91.9). Additionally, GPT-5.6 Sol offers a pricing advantage at $5 per million input tokens and $30 per million output tokens. In contrast, Anthropic's Claude Fable 5, launched earlier on June 9, encountered a significant setback when it faced a US government-mandated access suspension for 19 days, starting June 12, during its crucial adoption window.
Anthropic's Fable 5 also carries a higher price tag, costing $10 per million input tokens and $50 per million output tokens, roughly twice as much as Sol on input and 67% more on output. This pricing, combined with the regulatory-imposed downtime, has hindered Fable 5's ability to gain traction and justify its premium. While both companies remain private with high valuations—Anthropic at $965 billion and OpenAI at $122 billion—OpenAI's enterprise revenue overtaking its consumer revenue in 2026 is seen as a crucial signal of its growing momentum in the business sector.
The data, based on over 70,000 American businesses using Ramp, suggests that the enterprise AI market is expanding, with the percentage of companies paying for AI solutions climbing to nearly 56% by July. Despite Anthropic's $47 billion annualized run-rate as of May 2026, the growth rate comparison highlights a shift in momentum towards OpenAI. Analysts note that regulatory compliance and relationships are becoming critical competitive variables, as demonstrated by the impact of Fable 5's suspension.
