Yes, Allegiant Airlines does charge cancellation fees, but the amount depends on how far in advance you cancel and the fare you purchased. After the 24-hour cancellation window, passengers may be subject to a cancellation fee deducted from their refund or credit. The remaining balance is issued as a travel credit, which can be used for future bookings on Allegiant Airlines. If you’ve purchased Trip Flex, Allegiant’s flexible fare option, you can cancel without additional fees.