How to Change Airlines While Traveling
If you don't have a direct flight between your city of origin and your destination, you'll have to stop at least once along the way and board another plane. The second flight may be on another airline and may board in a different airport terminal, so knowing how to change airlines ahead of time can save a lot of time and stress once you land.
Print a terminal map for your connecting airport and bring it with you. You may also be able to find maps for select major airports in the back of your in-flight magazine.
Get off the plane when it lands at your connecting airport. Look around for a television monitor displaying a list of departing flights sorted by destination city. Find your flight and note the corresponding gate number (e.g., A21). Ask an airline employee for assistance if you do not see a monitor. Do not rely on the gate number printed on your ticket, as it may have changed while you were in the air.
Follow signs for your flight's terminal. Typically, the gate letter indicates the terminal. For example, for Gate A21, follow the signs for Terminal A.
Find your gate number once you are in the correct terminal. Look for a sign at the gate indicating the boarding time, which is usually 30 minutes prior to take-off. Walk around the airport, grab a bite to eat or use the restroom if you have time before boarding. Do not leave your bags unattended.
Confirm during the check-in process whether your checked baggage will be checked to your final destination or if you will have to claim it during your connection. Most of the time your bags will be checked all the way through, but if you purchased the connecting tickets separately, they will probably not. Find out ahead of time if your separate airlines offer an interline baggage agreement, which means they will transport a partner airline's checked bags on their behalf. Strongly consider taking your luggage as a carry-on in this situation, as claiming your bags means you will have to exit and re-enter the airport and may cause you to miss your second flight.
Pass through customs, declare any necessary items and have your passport stamped, and then proceed to your connecting terminal if your original flight is international and your second flight is domestic. You should not need to pass through customs or security if you are connecting between two international or two domestic flights.
Board your next flight when they begin boarding.
Speak with an employee at the airline desk or use a courtesy phone, if available, if you miss your connecting flight. Some airlines will automatically move you to a later flight if the missed connection is due to the late arrival of your original flight, but don't rely on it. If the missed connection is your fault, it is up to the airline whether to charge you for another flight to your final destination.