Declarations to Customs
When you enter Korea possessing traveler's checks over the equivalent of USD 10,000, you should declare the fact to the customs and acquire a Declaration of Foreign Exchange.
Exchange of Traveler's Checks at KEB
When you exchange your traveler's checks, you need to sign your name in the "Countersign" column in the presence of a KEB teller.
In the case of traveler's check less than the equivalent USD 20,000, visit the nearest KEB branch with your passport.
In the case of more than the equivalent of USD 20,000, visit the nearest KEB branch with your passport/ Declaration of Foreign Exchange and submit an Application for Sale/Deposit in Accounts/Withdrawal. (If you don't have a Declaration of Foreign Exchange, you should visit the Bank of Korea and acquire a Declaration Document of trading of the means of foreign payment.)
After exchanging your traveler's checks, keep KEB's certificate of foreign exchange purchased or receipt of foreign exchange purchased.(They might come in handy when you exchange Korean won into a foreign currency.)