You must declare foreign currency, Korean won notes and reportable checks when their combined value exceeds USD 10,000 on arrival in South Korea. This is a reporting threshold; amounts not exceeding it need no arrival declaration under this rule. KCS foreign-currency guidance
This guide concerns money physically accompanying you into South Korea. Its practical focus is counting mixed currencies and leaving customs with the right record. A bank balance or planned holiday budget is a different question.
Count won and foreign notes together
Make one inventory before making one conversion. Use separate rows for each currency and for checks. KCS explicitly includes won cashier’s checks in its arrival guidance; do not assume that only foreign banknotes matter. Items covered by KCS
A useful inventory has four columns: what you carry, original amount, dollar equivalent and where the item is packed. Keep ownership information alongside it if some funds belong to someone else. This is an organisational aid, not a substitute for the official declaration.
Count all your bags. A small emergency envelope in a passport pouch is easy to overlook when the main bundle is in a different compartment. Reconcile the physical count with your notes before using an exchange-rate calculator.
Worked example: three currencies, one total
Suppose your inventory contains:
- USD 7,800 in notes.
- Euros worth USD 1,700.
- Korean won notes worth USD 700.
The combined illustrative total is USD 10,200: 7,800 + 1,700 + 700. Comparing only the US-dollar notes with the threshold would miss USD 2,400 of the inventory.
These equivalents are assumed for the exercise, not current exchange rates. Keep the actual euro and won amounts visible in your working. Ask customs which conversion basis to use if the result is close to the boundary; the cited arrival page does not specify that basis.
Now remove the won from the hypothetical inventory. The remaining total is USD 9,500. That calculation explains why every currency matters; it is not a recommendation to rearrange money to avoid reporting.
Exactly USD 10,000 needs an exact count
The published arrival wording includes equality in the no-declaration side of the threshold. But USD 9,950 plus foreign notes equivalent to USD 75 is USD 10,025, not USD 9,950. Rounding the second amount down to “small change” changes the answer incorrectly.
For a borderline inventory, retain the unrounded calculation and ask before passing the declaration point. Do not extend this arrival wording to departure, where residence, source and purpose can change the procedure.
For comparison with another border on your itinerary, read our international cash guide. It explains why another country’s threshold or family calculation cannot simply be reused here.
Get the certificate before leaving customs
KCS instructs travellers with reportable amounts to enter the amount on the traveller declaration, submit it to an officer and receive a Certificate of Foreign Currency Declaration. It warns that the certificate cannot be issued after entry. KCS reporting procedure
Build that stop into your arrival plan. Before walking away, compare the recorded currencies and amounts with your inventory. Keep the original secure and a private digital copy accessible. A photograph of your own counting sheet is useful preparation, but it is not the customs-issued certificate.
Consider a traveller arriving with USD 12,400 who expects to spend only part of it. The useful task at arrival is documenting the incoming amount accurately, not predicting the exact departure balance. Write down later cash withdrawals or receipts separately so they do not become confused with the original funds.
Prepare departure as a new decision
Departure procedures depend on residence, source and purpose. Non-residents taking out foreign funds within their last arrival amount need the arrival certificate for the relevant exemption. KCS departure guidance
Before returning home, create three figures: the incoming amount, what remains from it, and any additional money acquired in Korea. For example, USD 12,400 minus USD 3,100 spent leaves USD 9,300; adding USD 2,000 received later gives USD 11,300 physically carried. The subtraction alone would describe the wrong departure inventory.
Use the South Korea accompanied-cash reference for country context. For business payments, earnings, unusual instruments or money carried for other people, give KCS the specific facts before travel. Airport security screening does not complete a customs currency declaration.