To update your designated companion on Southwest Airlines, you must log in to your Rapid Rewards account on the Southwest website or mobile app and navigate to the "My Account" section. If you have earned the Companion Pass, you will see a "Choose Your Companion" or "Change Your Companion" link. You are permitted to change your companion up to three times per calendar year. Before making the change, you must cancel any existing reservations you have for your current companion. Once the reservations are cleared, you can enter the new companion's name and details. The update is usually processed instantly, allowing you to book travel with the new companion the same day, though Southwest recommends allowing up to 48 hours for the system to fully reflect the change. If you have trouble online, you can also make the update by calling Southwest Customer Service at 1-800-435-9792.