North Cyprus has two mobile service operators, namely KKTCell (Kuzey Kıbrıs Turkcell) which everyone calls Turkcell which is actually the parent company based in Turkey. This company’s numbers start with 0533; and then there’s Telsim which is now owned in part by Vodafone, this company’s numbers start with 0542.
Both companies can offer competitive service rates, with GPRS, 3G as well as standard tariffs available. It’s who you prefer really, although KKTCell does seem to have a hold on the market at present. They both also offer your itemised billing via email, and have English speaking staff at their offices which are in all major towns and villages and even in some supermarkets. Staff can assist you with any problems that you may have with a phone or help you configure your phone for any number of applications and services.