New research has accused three of the UK's largest mobile phone operators of overcharging customers with long-running contracts.
The research, by Citizens Advice, said Vodafone, Three and EE, who together hold 59 per cent of the retail mobile market, charge customers the same price for their contracts even after the fixed-term deal is finished and their handset has been paid off.
Vodafone came out the worst, with customers being overcharged £25 a month on average, compared to £23 a month on Three and £22 a month on EE.
Owners of high-end handsets like the iPhone 7, Galaxy S8 and Xperia XZ Premium are overpaying up to £38 a month, the research suggested.
Gillian Guy, chief executive of Citizens Advice, said: “Mobile phones are now an essential part of modern life, but the way the cost of handsets are hidden within some mobile phone contracts gives phone providers a way to exploit their customers.”
The research found 36 per cent of customers do not cancel their contract when their fixed-term deal is up, while a fifth stay for over six months after, leading to them being overcharged.
A Three spokesperson has said they make the end-date of contracts very clear and they encourage all Three customers who would like to change their plan to contact them.
Vodafone has said they contact customers nearing the end of their contracts to offer a range of options, "wherever possible".
An EE spokesperson said separating phone and tariff can sometimes be more expensive, and they regularly update customers about their options.