Allegiant offers passengers three ways to check in: at the airport, online or via a mobile device. Online check-in starts 24 hours before and ends up to 60 minutes prior to the scheduled departure. Passengers checking in at the airport should arrive at least two hours before the departure time.
Online and mobile check-in are free. Passengers using airport check-in are charged a fee for the service, though there are some exemptions, as is the case for passengers with special needs. Passengers using online check-in should print their boarding passes before arriving at the airport, and all passengers must check in at least one hour before the scheduled flight departure.