There will be a $49 cancellation fee if you need to change your plans between 59 and seven days before travel. Additionally, there is a $79 cancellation fee if you need to change your plans less than six days before your departure. If you cancel a Frontier flight you'll get a credit for the price you paid in accordance with the Frontier refund policy. The credit has a 90-day expiration date, but you simply need to book a flight by that time; you are not required to fly on that day.