Passengers can receive a full refund if they cancel their flight at least 24 hours before departure. Southwest Airlines offers refunds if you cancel your flight at least 3 hours before departure. If you booked a ticket for travel to or from the US, the refund will be credited within a week. Here are some key points of Southwest Airlines’ 24-hour cancellation policy:
Source: https://support.google.com/voice/thread/305853097?hl=en&sjid=15917305590038096087-AP