On the last day of June, American Airlines agents at Gainesville Regional Airport in Florida canceled a North Carolina teenager’s flight after realizing that he had used a booking tactic called "skiplagging” or "hidden-city travel” — a method forbidden by airlines but used by some travelers to net flight bargains.

The teen’s father, Hunter Parsons, says it was his 17-year-old’s first time flying unaccompanied and that the timing and price of the booking made it appealing. For $150 (about ¥22,000), his son was to fly from Gainesville to Charlotte, North Carolina, and not continue on the second flight to New York, a cost savings of roughly $300 (about ¥43,000) if the family had simply purchased a direct flight to Charlotte. Parsons’ son didn’t even make it past the check-in counter in Gainesville, where airline agents questioned why the teen would fly to New York when his layover was in his hometown, Charlotte. He was forced to pay for a direct flight.

Skiplagging is buying a ticket for a connecting flight with a layover in the city that’s the real destination for the traveler. Flyers disembark after the first leg and simply fail to board the second. Often, the fare is cheaper than if they’d actually bought a direct flight to their desired destination. At least two websites now help unearth these deals for consumers.