Spend on your domestic debit or credit card overseas and you could be stung with steep foreign usage fees, so a £100 transaction could in fact cost you £109.

To prevent holidaymakers suffering from “post-holiday bank card bill shock”, Travelex has today launched the Supercard which incurs no fees and charges when spending abroad.

What is the Supercard?

It’s not quite a pre-paid card or a debit or credit card but it’s an electronic money payment product which links to your existing debit and credit cards so you can spend abroad.

It’s free to get and there are no fees or charges when spending overseas. Once you’re set up, it’s exactly like using your normal cards at home, just that you’re using them abroad so you won’t be stung with hefty foreign transaction charges.

Travelex claims “there isn’t a cheaper way to spend abroad” because there’s no mark up on the MasterCard wholesale exchange rate it uses so you get the exact same rate that Travelex gets.

But if you withdraw money from an ATM, you’ll be charged 2.99% of the transaction value. As it is a specialist card for foreign use, there are additional charges if you use it in the UK.

You can link up to five of your debit or credit cards to the Supercard, excluding American Express.

The Supercard launch follows a pilot scheme last year, which saved users nearly £1m in foreign fees and charges.

How to get a Supercard?

To be eligible you need to be 18 or over, a UK resident and have a UK bank account. You can apply online through the Travelex site.

You won’t be credit checked as it’s not a credit card, although a soft footprint may be left on your credit file. A soft footprint does not affect your credit rating.

The Supercard is free and there are no annual charges or dormancy fees. You’ll need to download the free app from the Apple Store or Google Play, register and then set up a Supercard password.

Once you’ve received the Supercard, you’ll need to activate it via the app and link your chosen cards to it. When using it abroad, it works on the Mastercard wholesale exchange rate, which tends to pip rates offered by Visa.

This means you can use the Supercard anywhere you see the Mastercard sign. It uses chip and pin technology and once you add your chosen cards, you can select your ‘primary card’ via the app from which the money will be deducted.

You’ll still be able to earn any cashback you are entitled to and the maximum amount you can spend on the Supercard is the same limit you get with your usual provider.

Via the app, you can keep track of how much you spend and approximately how much you save.

How does it stack up against other overseas products?

Importantly, the Supercard offers no Section 75 protection.

Section 75 protection means if you buy anything costing between £100 and £30,000 on a credit card and something goes wrong, your provider is equally liable for any breach of contract or misrepresentation by a company so you’ll be able to claim back any losses from the card supplier.

However, as Supercard is essentially a layer on top of your existing debit or credit card, you won’t get the same level of protection.

Andrew Hagger of financial research company MoneyComms.co.uk said: “If you’re only going to use the card for spending (and not cash) abroad then Supercard is a very competitive card with no charges. But if you take cash from an ATM the charge is 2.99% – so £2.99 per £100 withdrawn.

“I think most travellers on holiday use a reasonable amount of cash, particularly for bars, taxis and perhaps restaurants too to some extent so they would incur costs.”

Hagger says the top three credit cards for overseas spending – MBNA Everyday Plus, Creation Everyday Card and Halifax Clarity – are all cheaper options as they have no charges for overseas spending or ATM transactions.

“Debit cards from Norwich & Peterborough Building Society and Metro Bank (Europe transactions only) are also cheaper than Supercard as there are no ATM charges abroad,” he said.

See YourMoney.com’s Pick the right plastic for your summer holiday guide to find out how you can save £80 in charges on the cost of a fortnight spent abroad.