To check in online for an Allegiant Air flight, visit the AllegiantAir.com home page and click on Check-in. Enter your information, verify your seat and number of bags, and print your boarding pass.
Online check-in is available from 24 hours to one hour before the flight's scheduled departure time. You can look up your itinerary through your first name, last name and confirmation number, or by signing into your account.
Check in on a smartphone through the Allegiant2Go application. The application has the same options as the airline's online check-in feature. The application provides a paperless boarding pass on the smartphone. Allegiant2Go is available on iPhone and Android devices, as of June 2015. Mobile check-in is only available at certain airports.
Check in at the airport is available at Allegiant Air ticket counters. There is a fee for this check-in. This type of check-in is required for certain passengers, such as those with special needs, in which case the fee is waived. Checked bag fees are higher at the airport.
You can reserve seats when purchasing your tickets. If you don't, your seats are assigned during the check-in process. You can change seats online and through Allegiant2Go, but not at the airport.
Checked baggage must be dropped off at an Allegiant Air counter between four and one hours before the flight's scheduled departure time.