Originally Posted by
B407
Visa and MC will be no issue. Amex and Discover are rarely accepted. Credit card acceptance is pervasive in Korea so almost everywhere you go will accept it except for public transit systems and street vendors.
Beware of DCC if you don't speak Korean. Some merchants will just process the transaction for you and convert it to your home currency without asking you and the conversion rate is much worse than what your credit card company would charge you.
Restaurant transaction systems are not this complicated and just process as Korean won. Same for normal stores. Only major department stores might have this conversion option.