Quick Fact: By 2026, your Known Traveler Number (KTN) is a 9-digit code—letters and numbers—that unlocks TSA PreCheck at U.S. airports. KTNs from TSA PreCheck start with TT, while Global Entry, NEXUS, or SENTRI numbers begin with 98 or 99. Drop that number into your flight booking (or add it later through the airline’s website or app) so it shows up on your boarding pass.
Where does TSA PreCheck actually work?
TSA PreCheck runs in 200-plus airports across the country and covers over 80 airlines. Run by the Transportation Security Administration (part of Homeland Security), the program speeds up security for domestic flyers. Your KTN travels with you—no matter which airport you leave from. If your KTN is tied to Global Entry or SENTRI, you’ll also breeze through customs when you fly back into the U.S.
How much does everything cost?
| Requirement | Cost (as of 2026) | Duration | Where to Add |
|---|---|---|---|
| New TSA PreCheck application | $85 | 5 years | In-person enrollment center |
| Renewal (online) | $70 | 5 years | TSA PreCheck account portal |
| Adding KTN to existing booking | Free | N/A | Airline website/app or customer service |
Approval usually takes three to five days, but it can drag out to 90 days in busy seasons, says the TSA. Play it safe—apply or renew 60–90 days before your current KTN expires. Kids under 18 tag along for free when they fly with an adult who has PreCheck, but 18-year-olds and up need their own KTNs.
Why did TSA PreCheck start?
The program kicked off in 2011 as a way to move people through checkpoints faster. By 2026 it’s grown to over 12 million members, with enrollment centers in every U.S. state and a few overseas spots. KTNs were designed to tie together Global Entry, NEXUS, and SENTRI, so frequent travelers don’t have to repeat the same background checks. Fun fact: 75% of domestic flights now have dedicated PreCheck lanes, according to TSA numbers, but your boarding pass still has to show “TSA PRE” for you to use them.
What do I bring to the enrollment center?
Head to a TSA PreCheck enrollment center with a valid driver’s license, passport, or birth certificate. You’ll need something that proves who you are and where you live. The visit itself is pretty straightforward: an interview plus fingerprinting. Southwest flyers can drop their KTN into the “Add Secure Traveler Information” portal or dial 1-800-I-FLY-SWA. Other airlines have similar online or mobile options. If your boarding pass comes back without the “TSA PRE” mark, double-check three things:
- Is the KTN typed correctly in your airline profile?
- Does the name match your government ID exactly?
- Still no luck? Call the TSA Contact Center or your airline.
International travelers: a KTN tied to Global Entry (CBP) or SENTRI gives you two perks, but SENTRI by itself won’t put “TSA PRE” on your boarding pass unless you add the KTN to your reservation. Global Entry still costs $100 for five years and takes about the same amount of time to process.
