Flight Cancellation Procedures for Allegiant Airlines Making last-minute changes to your travel arrangements might be annoying! However, a few dire circumstances could develop and have a significant, overall impact on the journey. Do you use Allegiant Air? Do you anticipate making changes to your Allegiant Airlines reservation for any reason? You might find this manual useful. It will give you information on the comprehensive Allegiant Airlines ticket exchange policy. You must take into account a variety of possibilities, rules, and laws before submitting a request to modify a flight.