Only certain airlines will allow travelers to check in online, 24 hours prior to departure. If this option is available we recommend using it. When available, you can check in online on the airlines website using the flight booking reference number found on your e-ticket.
Passengers will be able to check in the number of bags they are bringing, and print their boarding pass during the advanced check in process.
If the option is available and it will not let you check in, this is probably because it is a group booking and you share the same reservation code with your group.
Do not worry! You can always check in once you arrive at the airport.