With 49 per cent of travellers reported as planning to use their cards to shop abroad, the average fee for overseas transactions of 2.75 per cent translates into a whopping £258 million going to the banks.

But almost half of those polled (47 per cent) have no idea that such charges are made, while 34 per cent of card users believe that they are not charged for overseas transactions.

Post Office head of lending Gary Fitton said Britons are now four times more likely than a decade ago to spend on plastic during trips abroad.

“It’s shocking not only to see how much people are being penalised to use their cards on holiday, but how few are aware of this,” he added.

Mr Fitton urged travellers to check with their credit card provider before they go about fees for using their plastic abroad.

“There are great value zero per cent deals available which can ensure you return home with only shopping bags and happy memories, and not a bigger credit card bill,” he concluded.

The Post Office’s study also pointed out that some debit card operators are beginning to make charges for the use of their cards in other countries.

A recent report by moneysupermarket.com claimed that Britons using a high street credit card could be paying an extra 12 per cent when using their card abroad than when using a card from some other providers.

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