Consumers using their credit card on holiday should be wary of extra costs that are sometimes added to their bill, advises a price comparison website.

While using plastic instead of taking out foreign currency can be more convenient, credit card companies may add as much as 2.99% of the purchase cost or cash withdrawal to customer's monthly statements.

Of the institutions researched, only the Post Office does not charge for using its product outside of the UK, although both Saga and Nationwide are free to use within the EU and charge 1% of the total purchase cost for the rest of the world.

Michelle Slade, analyst at the website, said that using a card to withdraw cash is not advisable as high rates of interest will be charged, meaning consumers pay back more than the cash they withdrew.

In addition, there is a handling fee levied on top of the foreign usage charge when money is withdrawn abroad.

She added: "£100 cash taken out on an American Express, HSBC or MBNA credit card will see you paying £5.99 in charges."