Southwest Airlines announced Thursday that it's changing it's policy and will now begin a new "no show" policy where fliers will forfeit their fares if they fail to show up for a flight. The policy is being implemented next month.

The airline said it's changing the policy to avoid having planes stuck taking off with empty seats at the last minute.

Passengers who have booked the Wanna Get Away or DING fares, which are the least expensive fares, on or after May 10, for trips scheduled for on or after Sept. 13, will be operating under the "no show" policy. The airline will not just re-book or cancel their flight. The rest of their itinerary will also be canceled, and passengers will have to buy a new ticket.

"It's not a fee," Gary Kelly, the CEO of Southwest, told USA Today. "All we need our customers to do is simply cancel their reservation, which puts us in the position of finding a replacement customer for that seat."

Southwest currently doesn't charge customers for changing their flight plans, making them the last big U.S. carrier not to do so. The airline is in the process of merging with the low-cost carrier AirTran, and has been the most consistent airline company in the industry in regard to making a profit.

The airline also differs from the majority of other domestic carriers in that it doesn't charge passengers to check the first two bags. However, it is no longer the cheapest airline to fly, and it has also begun to adopt fees for extra perks.

In January, the airline began charging passengers $40 to be part of group "A," which boards the plane first, a desired group as Southwest doesn't assign seats on its flights.

Southwest Airlines carries more domestic passengers than any other U.S. airlines.