Add your Known Traveler Number before you book or at check-in

Your TSA PreCheck Known Traveler Number (KTN) appears on your boarding pass when you enter it during online check-in or at the airport ticket counter. The airline uses this number to flag your reservation, which tells TSA screeners that you've already passed a background check and can use expedited security lanes.

You don't need to do anything special to "add" PreCheck to an existing boarding pass—you straightforward provide your KTN to the airline, and they print or display it on the pass. The best time to do this is during online check-in, which opens 24 hours before departure for most airlines. If you miss that window, you can add it at the airport before you reach security.

Key Takeaways

  • Your Known Traveler Number is a nine-character code that came in your TSA PreCheck approval letter or is visible in your TSA account online.
  • Enter your KTN in the "Known Traveler Number" field during online check-in on the airline's website or app, and it will appear on your boarding pass.
  • If you miss online check-in, tell the agent at the ticket counter your KTN before you go through security, and they can add it to your pass.
  • Your KTN must match the name on your ticket exactly, or the TSA system won't recognize it and you won't get expedited screening.
  • PreCheck status lasts five years from your approval date, so check your TSA account to confirm your membership is still active before you travel.

Find your Known Traveler Number

Your KTN is a nine-character code that TSA issued when you completed your PreCheck appointment and background check. You can find it in three places: your approval letter (mailed to you after your appointment), your TSA account online, or your PreCheck card if you received one.

To locate it online, go to the TSA PreCheck website and log in with your account credentials. Your KTN will appear on your account dashboard. Write it down or take a screenshot—you'll need it for every flight you take. If you can't find your approval letter and don't remember your login, you can call the TSA PreCheck program directly or visit an enrollment center to retrieve it.

Enter your KTN during online check-in

Online check-in opens 24 hours before your flight. Go to your airline's website or open their mobile app, enter your confirmation number and last name, and proceed through the check-in steps. You'll see a field labeled "Known Traveler Number," "KTN," or sometimes "TSA PreCheck Number"—the exact wording varies by airline.

Type your nine-character KTN into that field exactly as it appears in your approval letter. Do not add spaces, dashes, or extra characters. Your name on the ticket must match your name on your TSA PreCheck approval exactly, or the system will reject the KTN. Once you submit, your boarding pass will display your KTN, and you're ready to use PreCheck screening at the airport.

Add your KTN at the airport if you missed online check-in

If you didn't enter your KTN during online check-in, you can still add it at the airport. Go to the airline's ticket counter or bag drop desk before you head to security. Tell the agent you have TSA PreCheck and provide your KTN. They can update your reservation and reprint your boarding pass with the number on it.

This process usually takes a few minutes. The agent will verify that your KTN matches your ticket name and then issue a new boarding pass. Once you have the updated pass in hand, you can proceed to the TSA PreCheck security line. Arriving at the airport early enough to do this—at least 90 minutes before domestic flights—gives you time to handle it without rushing.

Verify your PreCheck membership is still active

TSA PreCheck membership lasts five years from your approval date. If your membership has expired, your KTN won't work at security, and you'll be sent to the standard screening line even if you enter it on your boarding pass. Check your TSA account before you travel to confirm your membership status and expiration date.

If your PreCheck has expired, you'll need to complete a new appointment and background check to renew it. The TSA PreCheck website shows enrollment centers near you where you can schedule an appointment. Renewal typically costs the same as the initial membership and takes about the same amount of time to process. Plan ahead if your membership is expiring soon, because the renewal process can take several weeks.

What happens when your KTN is on your boarding pass

When your boarding pass displays your KTN, TSA screeners will direct you to the PreCheck security lane at the checkpoint. In this lane, you can leave your shoes, belt, and light jacket on; keep your laptop and liquids bag in your carry-on; and move through the process faster than standard screening. You still go through a metal detector or body scanner, but the process is streamlined.

PreCheck status applies only to the airport where you're departing. If you're connecting to another flight, you'll need your KTN on that boarding pass too. Most airlines automatically carry over your KTN to connecting flights if they're on the same ticket, but check your second boarding pass to be sure. If it's missing, ask an agent at your connection airport to add it before you go through security again.

Common mistakes that prevent your KTN from working

The most common error is entering your KTN with spaces, dashes, or extra characters. Your nine-character code should be entered exactly as it appears in your approval letter, with no modifications. Another frequent mistake is having a different name on your ticket than on your TSA PreCheck approval—if you got married, divorced, or changed your name since your PreCheck appointment, you may need to update your PreCheck record before the KTN will work.

Some travelers enter an expired KTN without realizing their membership has lapsed. Always check your TSA account to confirm your membership is active before you travel. Finally, some people assume that entering their KTN on a boarding pass guarantees PreCheck screening, but TSA reserves the right to conduct standard screening on any passenger. Your KTN gets you to the PreCheck lane, but TSA makes the final decision about which screening process you receive.

Frequently Asked Questions

What if I don't have my KTN memorized?

You can look it up on the TSA PreCheck website by logging into your account, or check your approval letter. Many people take a photo of their KTN and keep it in their phone. You don't need to memorize it—you just need to have it available when you check in online or at the airport.

Can I use someone else's KTN on my boarding pass?

No. Your KTN is tied to your identity and your background check. Using someone else's number will cause the system to reject it, and you'll be sent to standard screening. Each person traveling needs their own PreCheck membership and their own KTN.

What if my boarding pass doesn't show my KTN even though I entered it?

Check that you entered it exactly as it appears in your approval letter, with no spaces or dashes. If it still doesn't appear, contact the airline's customer service before you travel. Your KTN may not have synced to their system, or there may be a mismatch between your ticket name and your PreCheck approval name.

Do I need to add my KTN every time I fly?

Yes. You need to enter your KTN during check-in for every flight you take. It doesn't carry over automatically between airlines or bookings. The process takes less than a minute during online check-in, so it's worth doing to may support you get PreCheck screening.

What if I'm traveling with my family—do they each need their own KTN?

Yes. Each family member who has TSA PreCheck needs their own KTN on their boarding pass. Children under 12 can go through PreCheck screening with an adult, but they still need their own PreCheck membership and KTN to get the benefit. If a family member doesn't have PreCheck, they'll go through standard screening.