Allegiant Air reservations may be made online at AllegiantAir.com or at the airport ticket counter. The airline prefers advanced reservations but does allow passengers to make last minute bookings. Reservations made within two hours of departure must be made at the airport.
The online reservation screen is on the website home page. Passengers are emailed an itinerary that is used to check in, select seats and print boarding passes within 24 hours of the flight's scheduled departure. Boarding passes may also be printed at the airport but, as of April 2015, Allegiant Air charges extra for this service.
Tickets are non-refundable. Changes to tickets must be made at least seven days prior to a reserved flight. Change fees are charged unless the airline's TripFlex travel protection is purchased.