Korea Customs splits its guidance into two separate questions that do not overlap: what is duty-free up to a value, and what is restricted no matter what it is worth. Both are published with real figures attached.
The $800 allowance, with its own carve-outs
The general duty-free threshold is “US$800 or less of the total taxable value of goods (for agricultural, livestock, and fishery products, up to 5kg of each good and 40kg of their total quantity and up to 100,000 Korean won of the price of all goods purchased overseas).” That is an overall $800 cap on taxable value, with a separate weight and value ceiling inside it for agricultural, livestock, and fishery products.
Liquor, cigarettes, e-cigarettes, and perfume sit outside that cap
These categories get their own allowance on top of the general one: “Apart from the section above (total volume up to 2L and US$400), 200 cigarette sticks, e-cigarette/liquid nicotine 20ml (Nicotine percentage less than 1%) and 100ml of perfume.” In practical terms: up to two liters of liquor valued at no more than $400, 200 cigarettes, 20 milliliters of e-cigarette or nicotine liquid under 1 percent nicotine, and 100 milliliters of perfume.
Minors do not get the alcohol and tobacco exemption
The age line is specific: “Minors under 19 years of age (based on year of birth) are not given tax exemption for liquor and cigarettes.” The parenthetical matters: eligibility is calculated by birth year, not by exact age on the day of travel.
Declare it yourself, or pay considerably more if Customs finds it first
Korea rewards voluntary declaration of goods over the allowance: “Voluntary declaration: 30% reduction from the standard customs duty.” The alternative is worse. If undeclared goods are found, the penalty is “Imposition of additional tax (40% more than the regular tax; 60% more if exposed twice or more within 2 years).”
Some goods bypass the duty-free threshold entirely
A separate category of restricted goods is not measured against the $800 figure at all: “All restricted goods need to fulfill all the requirements for customs clearance regardless of tax exemption threshold.” The source names some of what falls here: “Restricted goods: Firearms, Narcotics; animals and plants stipulated in the Convention on International Trade of Endangered Species of Wild Fauna and Flora (CITES) and their products, etc.” The source’s own “etc.” means this list continues beyond what we can quote, so check the Korea Customs Service page directly for anything not named above.
Cash and payment instruments over $10,000 must be declared
The requirement covers more than banknotes: “Means of payment, etc. exceeding US$10,000 according to Paragraph 1 of Article 5-11, Paragraph 2 of Article 6-2, and Paragraph 1 of Article 6-3 of the Foreign Exchange Transactions Regulations.” The rule for travelers is simple: cross $10,000 in payment instruments, and declare it.
Smaller categories most travelers will not hit
Mail, samples, and exhibition giveaways each have their own thresholds. Postal items worth “not more than US$150 which are received by a domestic resident and recognized to be intended for personal use” are duty-free; above $150, the same goods are dutiable. Sample goods follow the same pattern at $250: duty-free at or below it, taxed above. Free items handed out at an exhibition are duty-free only if their value is “not more than US$5” per visitor and the arrangement is approved by customs.
Prohibited on political and security grounds
Korea also prohibits certain content and instruments outright. That includes “Books, publications, pictures, movies, music records, video works, sculptures or any other items of similar nature that may disturb the constitutional order or be harmful to the public security or social customs,” and separately, “Items which may be used to disclose any confidential information of the government or engage in spy activities.” Counterfeit money is also named directly, in the source’s own wording: “currencies, bonds and securities whicih are counterfeited, forged or copied” are prohibited from import.
The restricted items list admittedly stops short
The restricted-goods category is introduced with an “etc.” that we cannot expand on, so treat the named items as a partial list, not the whole thing. It also does not state a fine or prison term for the political and security prohibitions, only that they are barred. If you are unsure whether something you are carrying falls into any of these categories, check the Korea Customs Service page directly rather than guess.