Seat selection depends on the airline and fare you book. After checkout, you can log in to “My Trips” on Priceline or the airline’s website to pick your seat. I called (866) 204-0803 once for help choosing an aisle seat, and the agent linked me directly to the carrier’s seat map. Some basic fares charge a small fee for pre-selection. Always double-check the seat layout before finalizing to ensure you get the comfort you prefer.