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 policy, 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 | british airways cancellation policy