While changing airlines while traveling may be more work than traveling on a single airline, it can save you money and time. You will have to do some homework, however, on check-in requirements and carrier locations in the airport.
If you have to make a trip with a connecting flight, it may be cheaper and quicker to travel on different airlines for each leg of the flight. If your first carrier has a long wait in the layover city, you may find another airline with an earlier flight. It also may be less expensive to fly from to a major hub on one airline, then from the hub to the destination city on a different airline.
Airlines require you and your bags to be checked in within a certain period before the flight. A standard domestic check-in requirement is 45 minutes with baggage, less with only carry-on baggage. The standard international check-in requirement is two hours. Thus, your layover time must be longer than these minimum requirements, especially if you're changing terminals or checking in.
A travel search engine may not give you all the airline options if you type in just your departure and destination cities. Search for flights to and from a major hub, such as Atlanta, Chicago, Houston or New York. Look for special packages. For example, if British Airways offers vacation packages to many destinations in Asia, it might be advantageous to travel from the United States to London, and then purchase a British Airways package for the rest of your trip. Check that you have adequate layover time before you book.
When you book your trip on multiple airlines, you might not be able to check in for all legs at your origination airport. If you have to check in at the layover airport, proceed to either the main check-in area for the connection airline at the front of the airport, or to a gate within the secure section of the airport. Which option you choose may depend on whether you are checking luggage.
When transferring airlines mid-trip, it is easier if you have only carry-on luggage. If you check your bags, however, the first airline may not check them in for the whole the trip unless the carriers are partners. You may need to collect your luggage from baggage claim after the first flight and re-check it before boarding the second flight. You may incur additional checked baggage fees.
