Claude Narrows ChatGPT's Lead in UK's £1 Billion Consumer AI Subscription Market

The study, a working paper titled "Who Pays for AI?" by economists Nikhil Datta, Peter John Lambert and Patrick Schneider of the University of Warwick, the London School of Economics and Imperial College London, is based on de-identified UK bank and card records covering about 14 million accounts. It is one of the first detailed looks at what consumers actually pay for AI rather than what they say they use, and it shows market share among paying customers can shift quickly.

ChatGPT's share of direct UK spending on AI subscriptions fell from 73.5 per cent in December 2025 to 52.5 per cent in July 2026, while Claude's rose from 7.4 per cent to 29.4 per cent, according to a summary of the paper published by FourWeekMBA. Google's Gemini held about 5 per cent over the same period. Claude's share roughly quadrupled, Bloomberg reported.

The researchers found that part of Claude's gain came from its users choosing more expensive plans. About 6.2 per cent of Claude subscribers paid for power-user plans costing £80 or more a month, against 0.3 per cent of ChatGPT subscribers, according to the summary. Roughly a quarter of Claude's increase in spending share between December and July came from existing customers upgrading, with the rest from new subscribers.

Switching also played a part. About a fifth of new Claude subscribers had previously cancelled ChatGPT, and the share of departing ChatGPT subscribers who moved to Claude within 60 days rose from 1.4 per cent through 2025 to 11.7 per cent between March and May 2026. The authors date the shift to the period after the release of Claude Opus 4.5 and the spread of Claude Code, the summary said. Major Anthropic model releases were associated with sharp jumps in new sign-ups, while OpenAI releases had little measurable effect on first-time subscriptions.

Paid adoption remains small but is growing. More than 5 per cent of British adults paid for their own AI subscription as of July, about double the share a year earlier, Bloomberg reported. The paper puts the number at about 2.8 million people.

The figures cover direct payments only. They exclude subscriptions bought through app stores, and some card issuers' privacy filters hide the Claude name, so those accounts were left out and the remainder reweighted to represent UK adults. The share figures therefore reflect spending rather than user numbers: among active assistant subscribers in July, ChatGPT still held 71.2 per cent to Claude's 27.1 per cent, according to the summary. ChatGPT Go, OpenAI's cheaper plan priced at £7 to £8 a month, mainly drew people who had never paid for AI before.

The data arrive as both companies prepare for public markets. Anthropic has filed for an initial public offering, and OpenAI president Greg Brockman said this week that the company now earns most of its revenue from businesses rather than consumers.