Airlines can't hold you hostage if you want to extend your stay for a leisure or work trip. But depending on what sort of ticket you bought, they can hold your money hostage – so in most cases you should be prepared to pay hefty fees to extend your airline reservations.
Changing Your Tickets
Most domestic U.S. airlines will offer you two ways to change your reservations well in advance: Either do it yourself online, or do it over the phone with the help of a customer service agent. If you use a customer service agent, watch out for extra service fees that may be tacked onto your fare, in addition to any standard change fees.
Ticket Changes at the Airport
You can also makes changes to your flight reservations at the airport. In fact, you might actually pay a much smaller change fee – about half the usual fee – if you're changing to another flight that leaves on the same day. Each airline's policy varies, but as a general rule, they require your new flight to have exactly the same itinerary (and be on the same airline, of course) to qualify for that reduced fee.
How to Get Out of Change Fees Entirely
If you accidentally booked the wrong ticket and noticed within 24 hours of the purchase, or decided you wanted a longer stay within that 24-hour window, you're in luck: The U.S. Department of Transportation requires that all airlines allow no-fee changes within 24 hours of your ticket purchase. And in very rare cases, an airline will buck the industry trend and not collect change fees at all – Southwest Airlines is the most notable example.
But for most flyers, there are two ways to get out of paying additional change fees. The first is to purchase a more expensive ticket class, like first class or business class, in which case change fees are usually waived. The second is to hold elite status with your airline's frequent flyer program; often, having your change fees waived is a perk of that elite status.
Airlines will also waive change fees if your tickets are rebooked because of natural disasters and other factors beyond your control or theirs. However, they may restrict which dates or flights your ticket can be changed to without incurring a fee. If you have a genuine medical or family emergency, they may also offer reduced fees or no fees at all for changes to your flight plans. This is usually done at the discretion of the airline agent, so be ready to offer proof of the emergency that's prompting your rebooking.