Log on to the website of the airline with which you are flying. For international flights, you may have a layover in another country and have to change airlines. You can still check in online and receive all of your boarding passes by checking in for your first flight.
Enter the information required by your airline. When you visit its website and choose the "online check-in" system, enter your last name and flight confirmation number, your flight number or your email address. The exact information required depends on your airline.
Provide your passport number and an emergency contact. Both are required for online check-in for international flights.
Upgrade your seat during the online check-in process for a fee, if upgrades are offered. Print your boarding pass and take it with you to the airport.
