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

Your TSA PreCheck number appears on your boarding pass only if the airline has it when they issue the pass. You can add it in three ways: during online booking, at the airport check-in counter, or through your airline's mobile app. The earliest you add it, the more likely it will print correctly on your first pass—some airlines sync the number when ready, while others take a few minutes.

The number you need is your Known Traveler Number (KTN), a 10-digit code that came with your TSA PreCheck approval letter or is visible in your TSA account online. You will need this number ready before you start the process, regardless of which method you choose.

Key Takeaways

  • Your Known Traveler Number must be entered into the airline's booking system before your boarding pass prints, or the TSA PreCheck indicator will not appear.
  • You can add your KTN during online booking, through your airline's app, or at the airport counter—but adding it early gives the system time to process it correctly.
  • If your boarding pass does not show the TSA PreCheck indicator, you can still use PreCheck at security if you have your approval letter or can show your KTN on your phone.
  • Each airline stores your KTN separately, so you may need to enter it for each carrier you fly with, though some airlines let you save it to your frequent flyer profile.

Adding your KTN during online booking

When you book a flight on the airline's website, look for a field labeled "Known Traveler Number," "KTN," "TSA PreCheck," or "Trusted Traveler Program." This field usually appears on the passenger information page, often near the fields for name and date of birth. Enter your 10-digit KTN exactly as it appears on your approval letter—spaces and hyphens matter to some systems, so copy it carefully.

After you complete booking, check your confirmation email. Your boarding pass should show a TSA PreCheck indicator (usually a small logo or the letters "TSA Pre✓") next to your name. If it does not appear within a few minutes, log back into your airline account and check the boarding pass there. If it still is not showing, contact the airline's customer service before you arrive at the airport.

Adding your KTN through the airline's mobile app

Most major airlines—including American, Delta, Southwest, and United—let you add your KTN directly in their app. Open the app, go to your booking or reservation, and look for a section called "Traveler Information," "Known Traveler," or "TSA PreCheck." Tap into that field and enter your 10-digit number.

Save the changes and refresh your boarding pass within the app. The TSA PreCheck indicator should appear within minutes. If you have already checked in and received a boarding pass without the indicator, you can still add your KTN in the app and request a new boarding pass at the airport counter or at a kiosk—the agent can reissue it with the PreCheck information included.

Adding your KTN at the airport check-in counter

If you did not add your KTN before arriving at the airport, you can give it to the agent at the check-in counter. Have your approval letter or your KTN written down so you can read it aloud clearly. The agent will enter it into the system and reissue your boarding pass with the TSA PreCheck indicator.

This method works, but it takes longer than adding it online or through the app. If the airport is busy, you may spend extra time at the counter. For this reason, adding your number before you travel is always faster.

What to do if your boarding pass does not show the TSA PreCheck indicator

A missing indicator on your boarding pass does not mean you cannot use TSA PreCheck at security. If your KTN is in the airline's system but did not print on your pass, you can still go through the PreCheck lane. Bring your TSA PreCheck approval letter or show your KTN on your phone to the TSA officer at the security checkpoint.

However, the safest approach is to fix it before you travel. Call the airline's customer service line, log into your account online, or visit the check-in counter early. Getting the indicator on your pass prevents any confusion at security and ensures you move through the PreCheck line without delay.

Saving your KTN to your frequent flyer profile

Many airlines let you save your KTN to your frequent flyer account so it automatically fills in every time you book. Log into your frequent flyer profile (usually under "Account Settings" or "Traveler Information"), find the Known Traveler Number field, and enter your 10-digit code. Save the changes.

Once saved, your KTN will appear on every boarding pass you generate with that airline account going forward. You will still need to enter it separately for other airlines, since each carrier maintains its own system. If you change airlines or update your frequent flyer account, double-check that your KTN is still there.

Common mistakes and how to avoid them

The most common error is entering your KTN incorrectly—a transposed digit or a missing character will prevent the system from recognizing it. Copy your number directly from your approval letter or TSA account rather than typing it from memory. If you are unsure of your KTN, log into your TSA account at tsa.gov to find it.

Another mistake is assuming the indicator will appear when ready. Some airlines process the KTN within minutes, while others take several hours. If you are checking in at the airport, add your KTN at least 24 hours before your flight to give the system time to sync. Finally, remember that your KTN is specific to you—it will not transfer to a family member or travel companion, even if you are on the same booking.

Frequently Asked Questions

What if I do not know my Known Traveler Number?

Log into your TSA account at tsa.gov using your username and password. Your KTN will appear in your account dashboard. You can also check your TSA PreCheck approval letter—the number is printed there. If you cannot find it, contact TSA at 1-844-TSA-PREK or visit a TSA PreCheck enrollment center.

Can I add my KTN after I have already checked in?

Yes. Go to the airline's website or app and request a new boarding pass, entering your KTN this time. You can also visit the check-in counter or a kiosk at the airport and ask the agent to reissue your pass with the PreCheck information. The new pass will show the TSA PreCheck indicator.

Do I need to add my KTN to every airline I fly with?

Yes, unless you have saved it to a frequent flyer profile with that airline. Each airline's system is separate, so you will need to enter your KTN for each carrier. Some airlines let you save it permanently to your account so it fills in automatically on future bookings.

Will my boarding pass show TSA PreCheck if I add my KTN at the gate?

No. Your boarding pass is already printed by the time you reach the gate. However, you can still use TSA PreCheck at security if you show your approval letter or KTN to the TSA officer, even if your pass does not display the indicator. It is better to add your KTN before you arrive at the airport.

What happens if my TSA PreCheck expires while I have a ticket booked?

Your boarding pass will still show the TSA PreCheck indicator, but TSA officers may not honor it at the security checkpoint if your membership has expired. Renew your TSA PreCheck before your flight date to avoid delays. You can renew online at tsa.gov or at an enrollment center.