A Known Traveler Number (KTN) is issued to all individuals approved to receive TSA PreCheck® expedited screening. The KTN must be added in the KTN field when booking airline travel reservations to have the TSA PreCheck® indicator appear on your boarding pass.
For members approved for the TSA PreCheck® Application Program, this number is 9 digits long, can be a combination of numbers and letters and typically begins with TT.
For members approved for Global Entry, NEXUS, or SENTRI, the KTN is the CBP PASSID. This nine-digit number usually begins with 15, 98 or 99 and can be found on the back of your NEXUS, SENTRI, or Global Entry card or by logging on to the Trusted Traveler Program website. Your trusted traveler card will not grant you access to TSA PreCheck® lanes, instead you must add your PASSID number in the KTN field when making airline reservations to ensure the TSA PreCheck® indicator appears on your boarding pass.