DALLAS, Texas -- Southwest Airlines is about to start hitting customers with higher fees to check in early for flights.
The Dallas-based carrier charges a flat $15 for early bird check-in so travelers can get better boarding positions for Southwest's open seating system.
RELATED: Southwest changing service animal rules for passengers
[Ads /]
Starting on Aug. 29, though, that flat fee will change to one of three fees: $15, $20 or $25 per one-way flight.
The price will depend on the length and popularity of early bird check-in for each way on the flight.
[Ads /]
Southwest says as early bird check-in increases in popularity, it wants to protect the value it offers its customers.