More than 12,000 organisations — from schools and fire services, to brands such as Ocado and Specsavers — use Esendex’s mobile messaging services to communicate with staff and customers. Darwin Private Equity led an £11m buyout from Esendex’s founders in 2013, and the group is now led by chief executive Geoff Love, 45. Strong demand in Europe and Australia, and the acquisition of financial services specialist Collstream last November, for an undisclosed sum, helped profits at the Nottingham firm rise to £3.2m in 2015.