https://www.lowfaresfinder.com/blogs/does-frontier-have-a-24-hour-cancellation-policy Frontier 24-Hour Cancellation: Frontier Airlines provides a 24-hour cancellation window for passengers to change or cancel their reservations without incurring fees. This policy applies to tickets purchased at least seven days before departure. Passengers must initiate the cancellation within 24 hours of booking to qualify for a full refund.