How to pay like a local in Korea.
The ultimate all-in-one card for tourists. Use it for payments, transit (T-money), and exchange cash at machines.
The standard transit card. Buy at any convenience store (GS25, CU, 7-Eleven).
Credit Cards
Visa/Mastercard are accepted almost everywhere (even small cafes).
Cash (KRW)
Keep some cash for street food and traditional markets.
Also useful
Need transit card info? T-Money Card Guide — where to buy and recharge your Korea transit card.