26. Sabio

Revenue: £152.5m (+53%)

Staff: 837

Customer experience strategies have "grown exponentially in importance" amid the shift to remote working, this London-based contact centre specialist said as it sought to explain a 53 per cent revenue hike in its year to 30 September 2021. Sabio now claims to have an addressable market of around £5bn after it entered the CRM space by acquiring Salesforce consultancy makeposetive in March 2021 (one of two purchases completed during the period). The Horizon Capital-backed Avaya, Verint and Amazon Connect partner generated £89m of its £152.5m top line from overseas.