JetBlue 24-hour cancellation policy allows passengers to cancel their flights within 24 hours of booking without incurring any cancellation fees. This policy applies to all fare classes and routes. Passengers can cancel their JetBlue flights online, via the JetBlue app, or by contacting JetBlue customer service. Beyond the 24-hour window, cancellation fees may apply, depending on the fare class and route of the ticket.