If customers do not board in time for their flight, they will forfeit their entire payment. If a flight is cancelled within 24 hours after booking, jetblue cancellation, like other airlines, will incur cancellation fees based on passenger destinations. The amount of a passenger cancellation fee is determined by when and why tickets are cancelled.. Cancel tickets as soon as possible after purchase to avoid paying a cancellation fee. Read more: alaska airlines cancellation policy | british airways cancellation