Revenue: £108.6m (+17%)
Net profit: 2.5% Staff: 151
Having broken the £100m revenue barrier in 2018, this Watford-based reseller is clearly in expansion mode, opening a 1,200 sqm warehouse and swanky new headquarters in quick succession. The HP, HPE, Dell, Cisco, Microsoft, Lenovo, Citrix and VMware partner hasn't filed any new accounts since calendar 2018, when it banked a £2.7m net profit on revenues of £108.6m. Founded in 2000, Storm claims to be one of the UK's fastest-growing VARs.