To add someone to your already booked Frontier Airlines flight, follow these steps: 1. Check Frontier’s Policy · Frontier does not allow adding a passenger to an existing reservation. · Instead, you will need to book a separate ticket for the new person. 2. Book a New Ticket for the Additional Passenger · Call Customer Service: 1 (866-284-3022) ... https://sites.google.com/view/airlinephonenumber/1-866-284-3022-how-to-add-someone-to-my-flight-after-booking-frontier