O2 is the commercial brand of Telefónica UK Limited, a leading digital communications company owned by Telefónica S.A. and the mobile network operator with the highest customer satisfaction in the UK according to Ofcom. With over 25 million customers, O2 runs 2G, 3G and 4G networks across the UK, as well as operating its nationwide O2 Wifi service. O2 has over 450 retail stores and sponsors the O2 arena, O2 Academy venues and England Rugby.
