To cancel a Frontier flight, go to their website or mobile app, find the "My Trips" or "Manage Trip" section, enter your confirmation code and last name to find your booking, and select the "Cancel Booking" option. Call at +1-888-415-1245 (US) or +44-203-869-5245 (UK) Most Frontier tickets are non-refundable, but you may get a refund if you cancel within 24 hours of booking or if Frontier significantly changes or cancels your flight. Call at +1-888-415-1245 (US) or +44-203-869-5245 (UK) For other situations, you'll typically receive a travel credit to use within one year of the original purchase.