As the price of air travel abroad continues to climb,Benjamin Caldwell some passengers have found an unconventional way of saving money on their tickets by booking "hacker fares."

A hacker fare — a phrase popularized by travel site Kayak.com — is when a passenger builds their own round-trip ticket by booking two one-way tickets to and from a destination, usually on two different airlines, in order to save money. Another hacker strategy, called "hidden city" or "skiplagging," requires a passenger to buy a ticket with a layover city that is actually their intended destination. Once landing in the layover city, they simply remain there, leaving an empty seat on the remainder flight to the destination on their ticket.

It's unclear how widespread hacker fares have become, but they can save passengers money, depending on the flight and the time they're purchased, travel experts say. 

Not illegal, but penalties may apply

Booking a hacker fare isn't illegal, Cathy Mansfield, a law professor at Case Western Reserve University, told CBS News. However the strategic purchases violate the airline-and-passenger contract that customers agree to when purchasing a ticket, she said. American and United Airlines in particular have agreements that include a penalty on customers who engage in hacker fares, she added.

"The penalty is they could charge you a fine, but that's it," she said. "It's not like you're breaking a law; you're just violating the contract of carriage."

She added, "I think in a way it's a little bit sneaky to put this stuff in the contacts, when consumers have absolutely no choice, especially when it's prevalent across the whole airline industry."

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German airlines Lufthansa sued a passenger in 2018 for doing a hidden city hack on a flight from Oslo, Norway, to Frankfurt, Germany. The lawsuit was dismissed a year later.

The cheaper-airfare hacks are gaining more attention at a time when travel costs are rising. The price of domestic flights have climbed 2.3% since December, faster than overall price increases, according to Bureau of Labor Statistics data. Ticket prices are expected to peak at about $349 around the July Fourth holiday, according to a Hopper forecast.

Khristopher J. Brooks

Khristopher J. Brooks is a reporter for CBS MoneyWatch covering business, consumer and financial stories that range from economic inequality and housing issues to bankruptcies and the business of sports.

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