A foreign transaction fee is a charge assessed by a credit card company when you make a purchase with your card in a foreign currency. This type of fee will often appear on your credit card statement as a separate charge. And the amount is determined by the cost of the purchase in U.S. dollars, not the currency in which you made the purchase.

You’ll typically be charged a foreign transaction fee when you make a credit card purchase in a different country. But it’s possible to be charged this fee when making a purchase in the U.S. if the purchase is routed through a foreign bank. One example is when you make an online purchase at a store that’s based outside of the U.S. If you’re charged this fee and think it’s an error, we recommend contacting your credit card issuer to sort it out.

Some cards advertise having no foreign transaction fees, but you can check the terms and conditions to find more specific information.

Foreign transaction fees vary, but they’re typically around 2.7% to 3% of the cost of the transaction. So that means you could end up paying an extra $3 for every $100 you spend in a foreign country.

That can be a notable extra cost, and it could exceed any benefits you might earn from rewards. For instance, if a card earns 1.5% cash back on every purchase but also carries a 3% foreign transaction fee, then the fee costs double the value of the rewards you’d earn for that purchase.

Any kind of card can come with or without foreign transaction fees. So a card issuer might charge this type of fee for all of the cards it offers, only a select few — or none at all.

Foreign transaction fees might not be a primary concern for everyone. For example, people looking to use a credit card primarily or solely for a balance transfer should be more worried about the terms of the introductory low-interest period than they are about foreign transaction fees.

The same is true if you’re looking for any credit card and don’t plan to travel internationally any time soon. In that situation, no foreign transaction fees might just seem like a nice bonus feature in case you eventually want to use the card abroad.

On the other hand, a card that charges foreign transaction fees might end up costing frequent international travelers. If you like traveling to other countries — even just once every few years — you should probably aim to have a card in your wallet that doesn’t charge this type of fee. Otherwise, you might end up paying so much in fees on a trip that it cancels out whatever benefit you get from the card.

Whether your credit card will be accepted internationally depends on each card’s payment networks, and availability can differ between merchants. For that reason, it’s difficult to say whether any one card is sure to be accepted everywhere internationally. A card that’s accepted at one store or restaurant might not be at another — it all depends on where you use it.

But while there’s no guarantee that your card will be accepted, foreign merchants that take credit cards as a form of payment are likely to accept at least one of the four major U.S. payment networks — American Express®, Discover®, Mastercard® or Visa®. So if you want to increase your chances of being able to use a credit card when you’re in a foreign country, we recommend carrying a combination of cards on at least two of those payment networks, with Visa as your best bet.