Korean Air bid upgrade program that allows passengers to bid for an upgrade to a higher class. With the bid upgrade program, passengers holding eligible tickets in Economy Class have the opportunity to place a bid to upgrade to Business Class or First Class. The program operates on a competitive bidding system, where passengers can submit their desired bid amount for the upgrade. However, it's important to note that bid upgrades are subject to availability and are not guaranteed. Passengers will be notified before their flight if their bid has been successful. To participate in the bid upgrade program, passengers can visit the Korean Air website or contact the airline directly for more information and to submit their bid.