Staff at the UK arm of OpenAI cost the business about £2.3m each on average last year, according to newly filed accounts for the London-based subsidiary of the company behind ChatGPT.
Total staff costs, comprising salaries, pension costs, share-based compensation and other benefits, reached £258m in 2025, up from £60.7m in 2024, the accounts show. The figure includes £87.3m in wages and salaries and £168m in share-based compensation.
The subsidiary employed an average of 110 people each month during the year. On those figures, employees received an average salary of roughly £794,000, and cost about £2.3m each once share awards and other benefits are included.
The subsidiary develops “UK-based commercial capabilities” for the OpenAI group and carries out research and development, which it charges to its parent company, according to the accounts.
Its turnover rose from £79.2m in 2024 to £293m last year. The company said the increase reflected the expansion of its sales and marketing and research and development activities, as part of the “substantial increase in the scale of the company’s operations during the year”.
The UK company put the costs associated with its research and development work at £117.8m, up from £48.2m in 2024. Higher staff costs contributed to administrative expenses of £264.1m, up from £64.6m a year earlier.
The accounts also record income of £4.7m from UK taxpayers through a research and development tax credit. The relief is a government scheme intended to encourage innovation, and HMRC guidance states that R&D tax reliefs support UK companies working on innovative projects in science and technology. Under the current rules, a merged scheme applies to accounting periods beginning on or after 1 April 2024. Business Matters has previously reported on how companies across a range of sectors use research and development tax credits to offset the cost of innovation.
When OpenAI announced the opening of its London office in 2023, it said it wanted to “build dynamic teams in research, engineering and go-to-market functions” in the UK.
“The teams in London will focus on advancing OpenAI’s leading-edge research and engineering capabilities while collaborating on our mission with local communities and policy makers,” it said at the time.
The company has since expanded its presence in the capital. In April, OpenAI signed a lease on an 88,500 sq ft office in King’s Cross with capacity for 544 staff, as Business Matters reported, as part of plans to more than double its London workforce from roughly 200 people at the time.
The broader OpenAI group is reported to be seeking to raise $30bn in funding at a valuation of about $1.4trn. It faces increased scrutiny of its losses and finances, with projections that it will burn through almost $280bn by 2030, amid deflationary pressure from Chinese rivals.
OpenAI filed confidentially for a stock market listing in June, after reports in May that it was working on an IPO filing with Goldman Sachs and Morgan Stanley. In September, however, Sam Altman, its chief executive, said the company would not go public in 2026 because of concerns about AI safety.
Critics of the company have said they suspect concerns about its financial position are a factor in that decision.
The International Monetary Fund warned this week that large-scale, debt-fuelled investment in artificial intelligence poses a new risk to global financial stability. The fund’s latest Global Financial Stability Report was published on 13 October during its annual meetings in Bangkok.
The UK accounts show staff costs rising more than fourfold in a single year, while the number of people employed by the subsidiary averaged 110.
The share-based element, at £168m, made up the largest single component of staff costs in 2025, ahead of wages and salaries at £87.3m. Pension costs and other benefits accounted for the remainder of the £258m total, according to the filing.
