People using credit cards may be paying out large sums of money in hidden charges, it has been claimed.
Costs which arise from processing payments made via a debit or credit card could see these expenses being transferred onto the customers.
Consumers could be paying as much as 200 per cent on top of their purchases if they choose to with their cards rather than dish out cash, according to consumer watchdog Which?
This is because banks levy a 0.8 per cent fee on retailers for processing credit card payments, while charging 0.1p for debit card payments, according to a Which? Money report.
Peter Vicary-Smith, chief executive of Which?, said: "While companies may want to recoup merchant fees, these charges need to be fair and transparent, so consumers know the real price before they begin a transaction."
Last month, Moneyfacts.co.uk advised consumers to keep a close eye on their credit card spending and ensure that they make repayments on time.