The Allegiant Air cancellation policy with Trip Flex add-ons allows you to cancel any ticket within 24 hours of purchase without being charged a cancellation fee. If you cancel within 24 hours by phone through Customer Care, you will be issued a refund. However, if you cancel online, you will be issued an Allegiant Credit voucher. If you want to know about allegiant air cancellation policy 24 hours then contact airlines at 1-844-902-2949 or visit our website: https://www.travomojo.com/cancellation-policy/allegiant-airlines-cancellation-policy/