UPDATE: SOUTHWEST’S CUSTOMER OF SIZE POLICY HAS CHANGED!
As of spring 2025, Customers of Size who request a second seat at the airport will only be given a second seat if the flight is not full. If the flight is full, the Customer of Size will be asked to take a later flight, regardless of how long that would require them to wait for another flight.
Customers who purchase a second seat in advance will only receive a refund after their travels if they request it AND if every flight on their itinerary was NOT full.