DCC means "dynamic currency exchange". That is to say, in the process of overseas credit card swiping, the acquiring bank converts the local currency into the currency selected by the cardholder in real time (generally the functional currency of the cardholder or the domestic currency), aiming at reducing the exchange risk of the cardholder from the transaction date to the repayment date. However, in currency exchange, a currency conversion fee of about 3% is usually added on the basis of the real-time exchange rate, so it is much higher than the normal exchange rate.

If you use a dual-currency credit card in consumption abroad, you'd better take the master to swipe the local currency. UnionPay may lose 0- 1.5%, and DCC will lose more than 3%. Therefore, in order to avoid DCC, you should stick to the currency of the country where you swipe your card, and choose UnionPay card or American Express card.