Customs exchange rate

It is neither the rate on the day you bought the goods nor the rate your card company settled at. It is the published rate for the week in which the import declaration is filed. Korea Customs averages the telegraphic transfer selling rates of the preceding Monday to Friday and publishes the result, which then applies from Sunday to Saturday. Cross a week boundary and the same goods have a different value for duty. The de minimis thresholds — USD 200 from the United States, USD 150 elsewhere — are judged in dollars, so the rate does not affect whether you are over them. It affects how much duty is charged once you are. This is why the amount on your card statement and the amount tax was calculated on do not agree. The card company uses the settlement date; customs uses the week of declaration. The two are not supposed to match. The current week's rate is published at unipass.customs.go.kr.