Do this before you book a flight. Unless you purchase an unrestricted ticket, you may be subject to penalties if you change or cancel your reservation.

When booking online, click on buttons that contain cancellation or rescheduling information. You typically can find airfare rules on the "conditions of carriage" section of the Web site. If you book on the phone, ask for the policies. You may be subject to rescheduling fees from $10 to $100 or more, depending on the airline, when you're traveling, and how you cancel.

Published July 30, 2008

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