Southwest airlines flight change policy Depending on the terms and conditions mentioned in the Southwest Flight Change Policy, the airline may provide you partial or full compensation if it changes your itinerary or flights for whatever reason. The airline will charge you a penalty fee if you opt to amend or cancel your flight reservation in the opposite scenario. For those with experience, the process will be straightforward, but it might be a nightmare for others who have never done it before. The whole process for modifying your Southwest flight is outlined below. You have two alternatives when trying to change your Southwest Airlines trip. Changes to Southwest Airlines can be made online or by phone.