The voltage difference is not an issue when moving between the UK and the EU.
All power supplies in PC's are equipped to cope with 220/240V 50Hz AC current (220V being Mainland Europe, 240V being UK). The only "issue" would be making sure a lead with the 2 pin EU plug on the end is packed with a desktop or server - otherwise a 3pin-to-2pin plug adapter will do.
Some desktops will even auto sense 110V/60Hz for US/Japan and a lot of others PSU's (Power Supply Units) have a switch.
All laptops are auto sensing for 110/220-240V 50Hz/60Hz for worldwide usage.