According to this website
Roughly 90% of all credit cards charge a 2% - 4% foreign transaction fee for any purchase processed outside of the United States. Such unnecessary, high costs can add up quickly for any international traveler or shopper, so it's a good idea to consider the increasingly popular category of cards that do not levy foreign fees
My Bank of America visa credit card charges me a fee and for that reason I have only used it once or twice in Ecuador in my 4.5 years here. For that reason, I am on a mission to get one that doesn't.