Southwest Airlines' cancellation policy allows passengers to cancel their flights without a fee within 24 hours of booking if the reservation was made at least two days before departure. After this period, cancellation fees may apply depending on the fare type. Basic Economy tickets are generally non-refundable and non-changeable. For Main Cabin, Premium Economy, Business, and First-Class fares, fees vary, but refunds or travel credits are usually provided for cancellations. Refundable tickets offer more flexibility, allowing full refunds. Passengers can manage cancellations online or via customer service at 1-888-486-7875. It's recommended to review specific fare rules during booking for detailed information.