According to the Frontier Airlines 24-Hour Cancellation Policy, travellers have seven days (168 hours) before the scheduled departure to cancel their flight and receive a full refund.
The same Frontier airline cancellation policy states that there are no fees for same-day ticket cancellations. Frontier wants customers to book with confidence, so they've made it as inexpensive as possible to make adjustments to your advanced reservation.
Frontier also wants to make sure that the software change is reasonably priced. Therefore, you must prefer to purchase the discounted package, the Works at the time of original booking if you book with the confidence to incur no modifications charge. Travelers who purchase the Works are entitled to the best seat on the plane, refundable purchases, one free carry-on bag, and one free checked bag.
Read also : Southwest Airlines 24-Hour Cancellation Policy| Jetblue Airlines 24-Hour Cancellation Policy
