Redeeming a Southwest reward or promo code in 2026 is a straightforward process handled during the booking phase on the Southwest website or mobile app. On the "Book a Flight" screen, look for the "Promo Code" field located just below the destination and date selectors. Enter your code there before hitting "Search" to see the discounted fares or point requirements. If you have a LUV Voucher or a Southwest Gift Card, these are entered on the Payment Screen at the very end of the checkout process. You must click on "Southwest Gift Card, LUV Voucher, or Flight Credit" under the "Payment Method" section and enter the voucher/card number and security code. For "Rapid Rewards" codes that grant points, you should log into your account and look for the "My Account" or "Promotions" tab to enter the code and have the points credited to your balance. Always check the expiration date, as Southwest is strict about code validity windows.