The most widely accepted credit cards are: Visa, MasterCard, Amex, and Diners Club.  To play it safe, I bring a couple of credit cards in addition to my ATM/debit card (and a back up!). In Hong Kong, you’ll likely have no problem using any of these (I’ve never had any problems—my issuing banks are large global ones). But it doesn’t hurt to have extras in case you lose a card for whatever reason.   Travelers checks are widely accepted in HK (not so much in China). Other tips: If a merchant asks you whether to charge a credit card with local currency or foreign currency, always go with local HK$ (otherwise it’ll be converted using the merchant’s usually higher exchange rate). Also, some sellers will add an extra charge (anywhere from 2-7%) if you pay by credit card, instead of cash. They’re technically not allowed to do this, but they usually get around it by calling it a “5% discount” for cash purchases. Finally, it’s a good idea to write in “HK” in front of the dollar sign when you’re signing your credit card receipt if you don’t see one already printed.