If you sign up for a Trusted Traveler Program (TTP) membership, you will receive an identifier called a Known Traveler Number (KTN). This is a nine-digit number, usually starting with 98, that gives you access to TSA PreCheck Global Entry lines at airports.
TTPs provide expedited re-entry to the U.S. through customs, as well as faster airport security processing. However, you must go through a pre-screening, pre-authorization process to qualify. The Department of Homeland Security offers the following TTPs:
- Global Entry
- TSA PreCheck (for travel within the U.S.)
Global Entry, NEXUS, or SENTRI members can find their KTNs on the back of their membership cards. If you belong to the TSA PreCheck program, you should look for something called a PASS ID number. You can find it by logging in to your account on the Trusted Traveler Program website. Your Global Entry, NEXUS, or SENTRI KTN number can be located this way, as well.
When you book a flight online, most airlines have a place for you to input your KTN or PASS ID number. This will ensure that you get access to the expedited services.