Separate the old purchase from today’s decision

After a trip, the original purchase price is often the first number remembered. It helps record past spending, but today’s cash proceeds and a future chance to use the notes are different questions.

This is a comparison method for leftover cash. It does not forecast exchange-rate movements or recommend holding a particular currency.

Calculate what a cash sale pays today

For an illustrative example, assume 100 foreign units remain, the customer’s selling quote is KRW 1,350 per unit, and a separate charge is KRW 5,000. The net proceeds are KRW 130,000. Do not reuse the cash buying rate from the original purchase.

100 × 1,350 − 5,000 = KRW 130,000

These are not live prices. Ask whether the provider handles coins, older designs, or damaged notes, and confirm whether the final amount already includes charges.

Write down the route into another currency

Distinguish a direct A-to-B quote from selling A for won and then buying B. Asking how many B units you receive for exactly 100 A units helps avoid reversing a cross-rate quotation.

B received via won =
(A amount × A selling price − KRW charge 1 − KRW charge 2)
/ B buying price

This assumes prices per one foreign unit and both charges in won. Subtract an A-denominated fee from A before conversion, and a B-denominated fee after conversion into B. Normalize any per-100-unit quote first, then compare available notes and treatment of remainders.

When keeping the notes is a practical option

Keeping notes may be useful if another visit is planned and the notes can actually be used there. Match the destination currency and payment method, and consider loss risk and storage inconvenience. The calculation does not establish that waiting for a hoped-for rate rise is worthwhile.

For storage, privately record currency, denominations, quantities, total, and location. There is no need to publish note photos or serial numbers.

Finish a short comparison record

  • Sell now: actual won proceeds after charges.
  • Change currency: final foreign amount received for the same starting cash.
  • Keep it: next usage date and whether those notes can be used.
  • For all options: note and coin quantities, provider conditions, and receipt.

Start with the quote-reading guide if transaction direction or quotation units are unclear.