Revenue: £113.8m (+12%)
Net profit margin: 8.2% Staff: 499
Organic growth and the contribution of recent acquisitions, including Union Solutions, helped this pan-European MSP's UK arm chalk up a £9.3m net profit on revenues that pogoed 12 per cent in its year to 30 June 2018. Client renewals or extensions during the year included William Hill and River Island. Globally, London-based Claranet employs 1,800 staff, operates 43 datacentres and has a revenue run rate of £375m. Vendor partners include AWS, Google Cloud, Microsoft and HPE.