TheAllegiant Air cancellation policyallows travelers to cancel their flight within 24 hours of booking for a full refund, as long as the departure is at least a week away. After 24 hours, cancellations may incur a fee, depending on the fare type. Allegiant does not offer refunds for non-refundable tickets, but passengers may receive travel credits for future use. Trip Flex ticket holders can make changes without extra fees. To cancel or modify your booking, contactourcustomer service at+1-860-321-4022.