Check your particular card
International card networks work with local payment companies in Korea. Those partnerships make payments possible at participating merchants, but they do not guarantee acceptance of every card at every terminal.
Check your issuer's overseas-use guidance before travelling. Keep access to its support service and any verification messages you may need.
UnionPay and JCB
UnionPay and JCB provide international acceptance information. Look for the relevant payment mark and ask the merchant whether your overseas-issued card is supported.
QR payments have their own app and merchant requirements. A shop accepting a UnionPay card does not necessarily support every UnionPay-linked QR wallet, or vice versa.
The Mobile Tmoney app lists supported overseas UnionPay and JCB cards for its visitor top-up route. Tmoney is a rechargeable transit card. Support in that app does not establish that a station machine accepts the same bank card for an ordinary Tmoney top-up.
Discover and Diners Club
Discover's network information identifies international acceptance partners, including BC Card in Korea. Ask whether the merchant can process your card if its logo is unfamiliar.
If a transaction is declined, the cause may be compatibility or bank authorisation. Do not assume the cashier's unfamiliarity is the only possible problem. Use another payment method and contact your issuer when needed.
American Express
American Express works at participating merchants. Confirm acceptance at your accommodation before relying on it for a room payment or deposit, and keep another card or cash for unsupported businesses.
A local processing relationship is not proof that every merchant accepts overseas Amex cards. The same caution applies to other networks.
Check retailer-specific policies
Some businesses have payment arrangements that differ from nearby shops. Check Costco Korea's policy for your exact card and purchasing channel before shopping.
Keep another way to pay
Visa and Mastercard have broad acceptance and can be useful alternatives. Carry a physical card even if you normally use a phone wallet, and keep some won for sellers without compatible payment facilities.
If a payment appears to fail, check whether it was authorised before trying again. Retain the receipt or error message if you need to ask your bank about it.
