Advertising technology is one of the UK’s most commercially mature startup sectors, powering the systems behind how brands target, deliver, measure, and optimise digital advertising. Investment in UK adtech companies reached a peak of £443.8m in 2022, and while funding dipped in 2023 and 2024, 2025 saw a strong rebound with £426.1m raised — more than five times the prior year’s £81.8m.
We’ve ranked the top 100 adtech companies by total equity raised (all data sourced from the Beauhurst platform).
What is adtech?
Adtech — short for advertising technology — refers to companies that develop the software, platforms, and tools used to plan, buy, deliver, and analyse digital advertising. This includes programmatic ad platforms, data management and audience targeting tools, ad verification and fraud prevention, content personalisation engines, digital signage, influencer marketing platforms, and analytics software.
The UK has more than 570 adtech companies currently active. This has increased 76% in the past ten years (2015–2025).
Collectively, UK adtech companies have raised £2.66b in equity funding so far, with £1.61b secured since 2020 alone. These companies employ an estimated 21,474 people and generate a combined turnover of £3.84b.
Key findings
- Rezolve, which develops mobile sales software using image and voice recognition to enable instant purchases from advertisements, tops the list with £178.4m raised. It is closely followed by GWI (£169.5m), a consumer data platform serving marketing agencies and global brands, and Amplience (£164.8m), a SaaS content management platform for retailers.
- London overwhelmingly dominates the ranking, accounting for 71 of the top 100 companies — the highest London concentration of any sector we’ve analysed. The South East and South West follow with nine and eight companies respectively, while Edinburgh’s cluster includes four companies such as TVSquared and AdInMo.
- The stage breakdown is notably different from earlier-stage sectors like PropTech and IoT. Established companies account for 25 of the top 100, reflecting the sector’s relative maturity and the fact that several AdTech businesses have been operating for over a decade. Venture-stage companies make up 31, with Growth at 21 and 16 companies already exited — a high exit rate that reflects the sector’s attractiveness to acquirers.
- The top 100 have collectively raised £2.11b — representing roughly 79% of all AdTech equity funding in the UK. The top five alone account for over £717m, highlighting the significant concentration of capital at the top of the market.
