Did you know that you can sometimes save money by buying more airfares than you actually need? This is called skiplagging.

For example. Let’s say you want to fly from New York to San Francisco. A direct flight might be $400, but a flight from New York to Seattle with a stop in San Francisco might be $250. So you could save $150 by buying the Seattle flight and getting off at San Francisco.

This travel trick, known as “skiplagging” or “hidden-city ticketing,” may save money, but some travel experts warn that it costs travellers in other ways.

For example, if you are skiplagging, you can’t check luggage, because any checked bags will go to your final destination. Even carry-on bags could get lost if the airline checks them at the gate.

This trick only works for one-way flights, since the airline will cancel any return flight if you don’t complete your first journey. Also, any changes to the flight route could send you to a different destination.

Travel writer George Hobica adds that skiplagging hurts other travellers by taking away seats they need. And as more people skip their flights, the number of empty seats increases, which can cause airlines to raise their prices. Because airlines often wait for late passengers, skiplagging can also cause flight delays.