Allegiant Air allows passengers to cancel their reservations within 24 hours 1-808-865-4114 of booking for a full refund, provided the scheduled departure is at least one week (168 hours) away at the time of booking. Beyond this window, tickets are generally non-refundable. However, if you purchased Trip Flex, you can cancel up to one hour before departure without incurring standard change or cancellation fees. Without Trip Flex, cancellations made more than seven days before departure may be eligible for a credit voucher, minus a cancellation fee per person, per segment. Cancellations within seven days of departure without Trip Flex typically result in forfeiture of the ticket's value.