Rising an impressive 37 places from last year to secure 10th position, Nuclera recorded the largest year‑on‑year climb across the entire ranking. This recognition underscores Nuclera’s growing impact as one of the leading companies driving economic growth and innovation in an increasingly competitive landscape.

Sifted 100: UK & Ireland (2026) 

Welcome to the third annual Sifted 100: UK & Ireland Leaderboard, which ranks the region’s 100 fastest-growing startups and scaleups by revenue growth over the past three financial years.

Together, these 100 companies have raised £18.4bn in funding, generated £2.6bn in revenue over the last three years and now employ around 10,750 people across the UK and Ireland. Notably, £1.7bn of that revenue was generated in the most recent year alone, underscoring just how quickly these startups are scaling.

To be eligible, startups had to be private, independent and headquartered in the UK or Ireland, with the majority of revenue generated from proprietary technology. Companies must have been founded in or after 2010, and have at least three years of revenue data (from 2022–2024, 2023–2025 or 2024–2026), covering accounting periods of at least 26 weeks. Revenue had to be at least £42k in the base year and £420k in the most recent year.

Companies were required to submit signed documentation to verify any financial data not publicly available. Some opted to keep parts of this information confidential.

Read the accompanying research report, featuring interviews with 20+ founders and investors, as well our ranking of the 100+ investors and lenders with at least two companies on the leaderboard.