United Airlines is the best airline where you can book your flights and even on cancellation requests for refund. Perhaps there are different conditions for refunds on separate bookings. So, the requirements may also deny you to fully refund your canceled flight tickets, but it may pay you partially or a percentage.

If your ticket is fully refundable, you can usually cancel your flight online. Look for a “My Trips” or “Manage My Flight” section on the airline's website; the name will vary per airline. Otherwise, you can call the airline's customer service Number. For more detail about the Korean airline cancellation policy Click here.