8. Insight

The UK arm of this global reseller behemoth smashed the £500m revenue barrier in its fiscal year ending 31 December 2017 thanks to a "strong performance" in its public sector business. Hardware sales led the way, swelling 23 per cent to £312m, while software sales dipped from £185m to £173m and services revenues jumped 28 per cent to £17m. This was more than matched at the bottom line, as net profits widened from £5.1m to £8.1m. In May, UK MD Emma de Sousa attributed the firm's uptick in fortunes to its investment in field-based sales staff, revealing that Insight now has three times as many staff in the field than it had three years previously.