How to Change Allegiant Flight If you are familiar with Allegiant's air change flight rules, the process of changing, changing or canceling a ticket is quite simple and convenient. Read on to learn more about flight policy changes and how they affect you. Allegiant's air change policy allows all passengers to make changes in accordance with the policy below. The traveler must make all flight changes seven days before the booked trip, without taking advantage of the flexibility of the trip. Allegiant charges a $75 flight modification fee for all changes. All adjustments are non-refundable and cannot be transferred to other travelers. Travel credits are valid for two years and cannot be renewed after expiration. Passengers can book a flight adjustment one hour before departure free of charge. Byer can change vacation packages 72 hours before the trip. The non-refundable component is the difference in ticket prices. Any change or cancellation of a flight presented within 24 hours after the purchase of the ticket is completely free of charge. Passengers who adjust the flexible travel option receive a travel coupon.