If you want to cancel. Frontier Airlines Flights then you can simply click on the cancel my seat option showing on the right corner of your mobile screen on the official website if you have login with your account. If you are canceling your ticket in the period of 24 hours then you can cancel your ticket and will get a full fee refund while if you have taken time more than 24 hours then you have to request to make your refund. While Frontier Airlines Tickets can be canceled online or offline. For the offline option, you have to rush to the airport, and then with the help of staff or agents, you can cancel your booked ticket.