Southwest cancellation policy travellers can use the official website in case they do not wish to continue with their flight. Calling the helpline number for cancellation is also an option. Thus, according to your preference and time you can either choose the online or the offline method. Southwest also provides a 24 hour free cancellation policy which offers travellers an option to get a refund on cancellation. In case passengers are cancelling after a risk-free period, they have to pay a cancellation fee.