Consumers are incurring costs of over £200 annually because they fail to fully understand the contractual terms imposed by broadband suppliers, according to new research.

A quarter of internet users in the UK have experienced hidden costs. The most common reasons for this include failure to use direct debit, missing payment deadlines and exceeding monthly allowances.

Rob Barnes, of the price comparison website Moneysupermarket.com, which carried out the survey, said: "With so many offers out there it's easy to be blinded by the headlines and enter into a contract without thinking about what it entails.

"Some providers look to make money in ways they're not prepared to tell you about upfront."

Virgin Media customers pay an extra £5 a month for using means other than direct debit, while Madasafish users are charged £2 a gigabyte after their monthly allowance.

Over half of new broadband customers admit they fail to examine the fine print in their contracts, which can leave them exposed to such additional costs.