Southwest Airlines is offering 30% off many flights this summer and fall, but the deal isn't available on every ticket.

With a Basic plane ticket, Southwest assigns a seat at the back of the plane, which is assigned at check-in. Also, flyers with that fare type will be the last to board the plane.

Southwest has come under fire recently after it announced the end of its long-standing practice of open seating, with assigned seating coming in 2026. In March, the company announced it was creating a new Basic fare and charging baggage fees, starting May 28, a shift from the current practice of allowing two free checked bags.