Known Traveler Number (KTN)
A unique identification number from a government trusted-traveler program that activates expedited security screening at participating airports.
A Known Traveler Number is the unique identifier assigned to a traveler who has been enrolled in and approved for a government-operated trusted-traveler program — such as TSA PreCheck, Global Entry, NEXUS, or SENTRI in the North American context. When the KTN is added to a flight booking, it is transmitted to the Transportation Security Administration, which designates the traveler for expedited screening on eligible flights. The traveler can then use dedicated PreCheck lanes at participating US airports.
Why it matters
For frequent business travellers, the KTN is the mechanism that transforms the airport security experience from a queuing exercise into a reliable, predictable process. TSA PreCheck lanes are shorter, faster, and require less disruption — shoes, belts, and laptops can stay in place. The time saving per security checkpoint is meaningful on a weekly or monthly basis, and the reduced stress of a predictable process has a real impact on traveler wellbeing. Organizations that pay for or reimburse PreCheck and Global Entry enrollment should guarantee travellers know where to enter their KTN in the booking workflow.
How it works in practice
The KTN is stored in the traveler's profile in the booking tool and is automatically populated into flight reservations. It is then transmitted to TSA through the airline's passenger pre-screening data. If the KTN is not on the reservation before check-in — or if the name on the reservation does not exactly match the enrollment name — the PreCheck designation may not appear on the boarding pass, defaulting the traveler to standard screening.
The takeaway
Add your KTN to your traveler profile in the corporate booking tool, the airline's loyalty account, and any other system used to make reservations. Guarantee the name on the enrollment exactly matches the name on all booking profiles. A mismatched middle name or initial between the TSA enrollment and the booking is the most common reason PreCheck fails to activate — an easily preventable frustration.