The more savvy mobile users out there will already know this, but it appears many mobile users in the UK are paying mobile operators money they don't need to. In a report by Which? that was posted last month, it states that around 46% of people continue to pay the full price of their monthly contracts even after their duration is over, which on average works out at overpaying £92 a year. Collectively, that's an estimated £355 million per year that the UK is giving to networks unnecessarily.
This is mainly because a large number of providers do not separate out the handset charge from the monthly airtime cost. There are exceptions, though, as O2, Virgin Media, Tesco Mobile and Utility Warehouse do allow monthly costs to be dropped once the handset is paid off. You can learn more by reading the Which? report on their website, along with details on their Unlock Better Mobile Deals campaign which aims to stop unnecessary charges to customers.