51. Altodigital - £40m

The bottom line was the big winner in FY12 for the south London-based print specialist, with operating profit growing by more than £1m to £3.2m. Sales were up from the £37.4m posted in FY11. On top of print, audiovisual and digital signage hardware, the firm also sells office supplies. Leading vendor partners include Kyocera, HP, Canon and Lexmark. Crawley Borough Council and Lincoln College are among Altodigital’s top customers.