Five AI firms feature in UK’s fastest-growing businesses

Five AI-focused companies appear in the ORESA Executive Search Growth Index 2026 ranking of the UK’s 100 fastest-growing businesses, suggesting AI firms are gaining ground in Britain’s scale-up market.

The ranking identified five AI pure-plays in the top 100, alongside three other companies that put AI at the centre of their offer while operating outside the core technology sector. The index measures growth by two-year compound annual growth rate in revenue, using Companies House data.

Shop Circle was the highest-ranked AI business, placing 10th overall with a compound annual growth rate of 259.8%. It is building an AI-native software platform through the acquisition and integration of software businesses.

Synthesia ranked 17th with a 160.5% compound annual growth rate, while PolyAI placed 46th at 103.5%. Yoti ranked 72nd and Luminance 98th, completing the five specialist AI companies on the list.

Three other companies in the ranking point to broader AI adoption across established business models. Cleo, ranked 44th, describes itself as an AI financial assistant, while teacher recruitment platform Zen Educate, in 61st place, uses AI-driven matching to connect schools with educators. Insurance provider Marshmallow, ranked 69th, uses machine learning in underwriting and pricing.

Outside the specialist software category, Pure DC was the closest example of an AI infrastructure business on the list. The data centre consultancy ranked 16th overall with a 171.2% compound annual growth rate.

AI presence

The findings suggest AI is becoming more visible among fast-growing UK companies, though it still makes up a modest share of the ranking. Financial services remained the largest sector overall, accounting for a quarter of the companies featured.

Healthcare also gained ground, with biotechnology businesses contributing strongly to sector performance. Retail returned to growth after more difficult years, reflecting demand for health, wellbeing and value-led products.

The average company in this year’s ranking recorded compound annual revenue growth of 136.1% over two years. Combined annual revenue for the 100 businesses exceeded GBP £11 billion.

The list spans a wide mix of sectors, from electric buses and art galleries to media and food chains. That breadth suggests AI is emerging as one theme among many in the scale-up market, rather than the dominant force.

Orlando Martins, Founder, Growth Index, commented on the pattern.

“What’s striking is not that AI companies are dominating the rankings – they aren’t, as of yet. What’s striking is that AI is increasingly visible in many different forms, beyond specialist AI businesses. In conversation with many of the UK’s high-growth leaders, we’re seeing companies in sectors such as fashion, insurance and health using AI as a core enabler of both growth and profitability.

“Because Growth Index is based on the latest available full-year accounts, it reflects a period when many businesses were still experimenting with AI rather than fully integrating it into their operations. It will be fascinating to see whether the UK’s AI-native businesses occupy a substantially larger share of future rankings, or whether the bigger story proves to be the widespread adoption of AI across existing industries,” said Martins.

Top rankings

Among technology-related businesses in the index, Shop Circle led the group, followed by Pure DC and Synthesia. Asun Services, a technology services provider, ranked 35th with a 142.1% compound annual growth rate, placing it among the stronger performers in the sector.

PolyAI’s 46th-place position put it in the middle tier of the top 100, while Yoti and Luminance appeared lower down the table. Even so, their presence suggests revenue growth at AI-led companies is translating into a larger presence in broader business rankings.

The methodology sets a minimum base-year turnover of £100,000 and a minimum final-year turnover of £5 million. That means companies in the ranking have moved beyond very early-stage growth and reached a more substantial level of commercial scale.

For AI businesses, that threshold matters because much of the debate around the sector has centred on investment, experimentation and adoption rather than revenue performance. The latest ranking offers a snapshot of which businesses are converting that interest into measurable sales growth.

It also shows that many of Britain’s strongest scale-up performers still come from outside the specialist AI field. For now, AI appears to be spreading through sectors and business models at least as quickly as it is producing a dominant class of stand-alone winners.

Together, the Growth Index 100 generated more than GBP £11 billion in annual revenue.