To clarify: How much does it cost for a 02 number prefix number on the o2 mobile phone network? It costs between 3p and 55p on that specific mobile system, but note that numbers are approximate. Numbers which begin zero 2 are known as geographic numbers and linked to specific areas of the UK.
O2 is the more usual name given to Telefonica UK Ltd. Previously known as Cellnet and mmo2 plc O2 was taken over by Telefonica in 2006. It has a number of 2G, 3G and 4G phone networks throughout the networks. It has sponsored the arena in Greenwich since 2007 which was known as the Millenium Dome until the redevelopment.
If you have problems with your call charges on your mobile phone please contact Ofcom with your details.