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.

To ensure the TSA PreCheck indicator appears on your boarding pass, your "Known Traveler Number" (KTN) must be correctly entered into your airline profile before you check in. When booking a flight, there is always a field for "Known Traveler Number"—make sure the 9-digit number from your Global Entry or PreCheck card is entered exactly. If you've already booked, you can go to "Manage Trip" on the airline's website to add it. Crucially, the name on your airline ticket must be an exact match to the name used for your PreCheck application; even a missing middle initial or a hyphen can prevent the system from validating your status. If you check in and don't see the "TSA PRE" logo, do not go to security yet; instead, visit the airport check-in counter. An agent can often re-sync your profile and reprint your pass with the correct status. Remember that PreCheck is not 100% guaranteed for every flight, as the TSA occasionally uses "random exclusion" for security audits, though this is rare for most frequent travelers.