What is southwest airlines flight change policy? You can alter your flight by calling Southwest Airlines customer care if you know the below rules. It is well known that Southwest Airlines does not impose fees for flight changes. You also need to know a few facts about Southwest Airlines' change flight policy. If you need to change your flight, do so at least an hour before takeoff to avoid paying additional costs or experiencing a price increase. If you don't cancel your airline ticket before the cutoff, you will need to do so, and there could be a fee. Ten minutes before your planned departure is the deadline.