A third of mobile phone customers are still being charged the full price of their contract after they have paid off the cost of their phone, consumer rights group Which? has said.
Consumers overpaying for phones
Which? is now calling for phone networks to stop overcharging customers, which costs an estimated £182m a year.
The consumer group found that 36 per cent of people whose contract ended in the past two months are still paying off the price of their smartphone, estimating that some people may be out of pocket of more than £400 every year.
However, this is despite phone providers promising regulator Ofcom that customers would get a reduced tariff after their contracts end from February 2020.
The survey questioned 4,006 people across the UK last month, including 856 customers whose contracts had expired in the past year.
Which? claims that Three was the worst provider for customers overpaying, with 43 per cent of customers whose contracts ended in the past six months seeing no drop at in their monthly bill price.
Around 40 per cent of EE customers saw no price drop at the end of their contract, with 31 pent of Vodafone customers also seeing no change.
End-of-contract discounts for EE and Vodafone did come into effect, but only after three months of their contract ending, which meant many customers were still left overpaying.
Natalie Hitchins, head of home products and services at Which?, said: "While some mobile firms have taken action to end overpayments, our research suggests that others could do a lot more to ensure that customers are not being exposed to rip-off charges.
"Ofcom should ensure that all providers are treating their customers fairly and have taken enough steps to stop people overpaying."