Carrying cash from South Korea to United States
Two separate rules apply to any cash journey: one where you leave, one where you arrive.
Do you need to declare?
Yes: and on both legs of the journey. Leaving South Korea, Korea Customs Service requires a declaration above USD 10,000. Entering United States, U.S. Customs and Border Protection requires a declaration above USD 10,000. The two rules are independent: satisfying one does not satisfy the other.
Travelling as a family or group?
The threshold applies to your combined total, not per person. A family of four each carrying a little under the limit is still over it, and splitting cash between travellers to stay under does not make it legal.
The two legs
| Leg | Limit | Form | Authority |
|---|---|---|---|
| Leaving South Korea | USD 10,000 | Traveler Declaration Form | Korea Customs Service |
| Entering United States | USD 10,000 | FinCEN Form 105 (CMIR) | U.S. Customs and Border Protection |
Means of payment, foreign currency, Korean won notes or cashier's cheques, exceeding USD 10,000 in total must be declared on departure.
There is no limit on how much you may carry; amounts over USD 10,000 must be reported.
If you do not declare
South Korea: Failure to report is subject to fines or penalties.
United States: Seizure of the currency and possible civil and criminal penalties.
There is no limit on how much you may legally carry in either direction, the duty is to report it, not to keep under it. Failing to report is the offence.
Currencies
South Korea uses KRW; United States uses USD.
Sources: rules as of 22 September 2026. This is general information, not legal advice; always check the official authority before travelling.