As with all international flights, when boarding a Korean Airlines plane for international travel, passengers must show a valid passport and boarding pass. If passengers have carry-on luggage, it must also conform to the number of items and dimensions set forth by the airline.
Most documentation required of international travelers is attained and evaluated once an international flight lands at its destination airport rather than prior to departure. When an international flight arrives in a different country than that from which it departed, passengers must undergo a customs check. During this process, customers must again show their passport as well as visa permitting entry into the destination country, if applicable. Visa laws vary by country. To enter South Korea, American citizens do not need a visa if their stay is less than 90 days. Passengers may also be asked other questions about their visit, such as the length of their intended stay, the purpose of the visit and the address of their residence while in the country.
Once passengers have answered the questions to the satisfaction of the customs agent and their passport and/or visa numbers are validated and cleared, they are free to enter the country. If passengers are not able to show valid documentation or provide satisfactory answers to the questions asked of them by the customs agent, they may be detained and/or ultimately sent back to their country of origin.