Revenue: £272.3m (+6%)
Net profit margin: 1.2% Staff: 598
This global Cisco Gold partner was rolled into an $11bn-revenue business known as NTT Ltd on 1 July 2019. Having acquired Dimension Data in 2010, Japanese parent NTT has now united the networking specialist with NTT Security, NTT Communications and 25 of its other businesses. The new firm is based in London. Dimension Data's UK business posted revenues of £408.4m in its most recent accounts covering an elongated 18-month period, equating to a six per cent rise pro rata.