If you lose something in Korea, first narrow down where it was last seen. If it was on a subway, railway, bus, taxi, at an airport or inside a major facility, contact that operator or its lost-property center as soon as possible. Operators can often check items before they move into a wider lost-property process.
Korea's National Police Agency operates LOST112, an integrated lost-and-found portal that brings together police records and found-property information from participating institutions such as transport operators and public facilities. The portal also publishes a directory of lost-property centers, including subway systems, airport rail, airports and other major operators.
Use a precise description: item type, brand or model, color, distinctive marks, where and when you last had it, and any safe identifying details. For a phone or wallet, protect accounts and payment cards separately rather than waiting for the physical item to be recovered.
If theft or another crime is suspected rather than simple loss, contact police at 112. For ordinary lost property, use the relevant operator and LOST112 as complementary routes. The portal's Korean-language account and reporting flow can be harder for some international visitors, so a hotel desk, tourist information center or 1330 travel helpline may be useful for language assistance.