If you’re considering flying with United Airlines anytime soon or already have something booked, it’s a good idea to learn the cancellation and refund rules. This way, if something comes up and your travel plans change, you’ll know how to cancel your flight.If you’re considering flying with United Airlines anytime soon or already have something booked, it’s a good idea to learn the cancellation and refund rules. This way, if something comes up and your travel plans change, you’ll know how to cancel your flight.