Sometimes a card gets unexpectedly declined at a shop. In the past I only ran into foreign card problems at big hotels or department stores, but these days it happens more often because of terminal settings or authentication methods at small shops, street stalls, and cafes. So you need to prepare more than before. ## Why are they declined The terminal can't accept overseas payments (EMV/chip·IC or contactless), or the card issuer blocks the transaction for security reasons. Sometimes it asks about DCC (payment in your home currency), and it's declined then. Because authentication (3D Secure) requirements differ, a card meant for online use might be blocked for offline transactions. Each card issuer has different risk-transaction criteria, so overseas use can sometimes be automatically blocked. ## Actions you can take immediately 1) Try using a different terminal or ask another staff member. 2) Call your card issuer right away using the emergency contact number on the back of the card and request approval for the overseas payment. 3) Be prepared with cash, mobile payment apps, or a transit card (topped up). Sentence to use: “My card isn't being approved. Could you try another terminal?” When you call, check the customer service number on the back of your card and tell the operator 'please approve overseas payments' — they often temporarily lift it. They may require verification by text or app, so have your smartphone ready. If a DCC screen appears, 'paying in KRW' usually adds extra fees, so it's better to pay in 'local currency' if possible. If you don't have cash, ask the shop if they accept transport cards or mobile payments.