Make sure your Known Traveler Number (KTN) is shown under Personal Information in your MileagePlus profile after logging in to add TSA PreCheck to a United Airlines reservation. To amend the Traveler Information for an already-made reservation, go to Manage Reservations, How Do You Add TSA PreCheck to United Airlines choose your flight, and enter your KTN there. Additionally, you can enter your KTN when checking in online or provide it to a United representative at the airport. When TSA PreCheck is added, it will appear on your boarding pass and, if applicable, grant you access to the accelerated security screening lanes.
