The Post Office has entered the mobile market with the launch of a pay-as-you-go service. The mobile offering -- called Post Office Mobile -- uses EE's network and is designed to offer an alternative for the 44% of mobile users who don’t have a contract. Calls to both landlines and mobiles will be 8p per minute while it will cost 10p per text -- which is up to 77% cheaper than other networks -- although customers will only be able to access 3G networks, not the faster 4G speeds.