What is Flying Standby?

At one point, flying standby meant that if there were empty seats on an earlier flight on the same route (and airline), you could change to that one for free. These days, most airlines charge for the service, the exception being for elite flyers. Two other exceptions: Southwest and JetBlue both offer free same-day changes (though, depending on your fare, there can be a $75 standby fee on JetBlue; on Southwest, standby is free). 

It’s important to note that some fare classes, like basic economy, may be ineligible for the service at all, whether paid or complimentary.

If you’re looking to fly standby, the process differs by airline. On some you might be able to add yourself to the list and pay the fee online, or you might have to call the airline. If you’re already at the airport, you can typically request standby at check-in or at the gate. Usually, standby seats are filled on a first come, first served basis. You might not clear on the standby list until boarding is complete.

You might also fly standby if you’ve missed your flight (because, for example, your connecting flight was delayed) and the airline isn't sure there will be seats on the next available flight.

Same-day standby flights are free on Southwest (though you'll have to pay the fare difference for a confirmed change if you have a Wanna Get Away ticket). Other airlines charge anywhere from $25 to $75 for the service.

Only airline employees and their companions flying on a buddy pass can really save money through flying standby. Otherwise you’ll have to already have purchased a ticket to even fly standby at all, and in most cases, you’ll pay at least a small fee to do so, unless you’re an elite flyer.