Yes, you can add your Known Traveler Number after you book, but the timing and method depend on which airline you booked with

You do not have to add your Known Traveler Number (KTN) at the moment of purchase. Most airlines let you add it to your reservation afterward through their website, mobile app, or by calling their reservations line. The sooner you add it, the better — ideally before you check in — but you have some flexibility. If you already have your confirmation number, you can log into your airline account and update your passenger details to include the KTN.

The process is straightforward on most carriers. You will find a "manage my booking" or "edit passenger information" section where you can enter your KTN in a designated field. Some airlines ask for it during online check-in if you have not added it earlier. The key is that your KTN must be in the system before you arrive at the airport for it to work with TSA PreCheck screening.

Key Takeaways

  • You can add your Known Traveler Number through your airline's website, app, or by phone after booking without changing your flight or paying a fee.
  • The best time to add your KTN is before you check in, though some airlines allow you to add it during online check-in up to 24 hours before departure.
  • Your KTN must match exactly as it appears in your TSA PreCheck record, including any hyphens or spacing.
  • If you add your KTN after checking in, you may not see the TSA PreCheck indicator on your boarding pass, but you can still use the PreCheck lane if your name matches TSA records.

How to add your KTN through the airline website

Log into your airline account using your confirmation number and last name, or your frequent flyer account if you have one. Look for a link labeled "manage booking," "edit trip," "passenger details," or "trip management" — the exact wording varies by airline. Click into your reservation and find the section for passenger information.

You will see a field for "Known Traveler Number," "KTN," or sometimes "TSA PreCheck number." Enter your nine-character KTN exactly as it appears in your TSA PreCheck approval letter or in the TSA PreCheck program website. Do not add spaces or dashes unless they are part of your actual KTN. Save the changes. The update usually takes effect when ready, though some airlines may take a few minutes to sync the information.

Adding your KTN through the airline app

Most major carriers have a mobile app that lets you manage your booking on the go. Open the app, sign in, and find your upcoming flight. Tap "manage booking" or "trip details," then look for the passenger information section. The KTN field is usually near your name and date of birth.

Enter your nine-character KTN carefully — a single typo will prevent TSA from matching it to your record. After you save, check that it displays correctly. If you are within 24 hours of your flight, some airlines let you add it during mobile check-in instead, which is even faster.

Adding your KTN by phone or at the airport

If you prefer to speak with someone, call your airline's reservations line with your confirmation number ready. A representative can add your KTN to your reservation over the phone in a few minutes. This is a good option if you are unsure whether you entered your KTN correctly online or if you just received your TSA PreCheck approval and want to confirm it is in the system before you travel.

You can also add your KTN at the airport ticket counter or gate, though this is the least reliable option. If you do this, the TSA PreCheck indicator may not print on your boarding pass, and you might not have time to get it added before you reach security. It is better to add it online or by phone beforehand.

What happens if your KTN is not in the system before you fly

If your KTN is not linked to your reservation when you check in, your boarding pass will not show the TSA PreCheck indicator. However, you may still be able to use the TSA PreCheck security lane if your name matches TSA records and you have your KTN with you at the airport. You will need to tell the TSA officer that you have a valid KTN and show proof — your approval letter or the TSA PreCheck website printout.

This is not may provide to work, and you may be sent to the standard security line instead. To avoid this hassle, add your KTN to your reservation as soon as you have it, ideally before you book your flight or when ready after.

Common mistakes when entering your KTN

The most frequent error is mistyping the nine-character number. Your KTN is not your TSA PreCheck membership number or your frequent flyer number — it is a specific identifier issued by TSA. Check your approval letter or log into your TSA PreCheck account to find the exact number, including any hyphens or spaces that are part of it.

Another mistake is adding your KTN to the wrong passenger if you are booking for multiple people. Make sure you are editing the correct traveler's information. If you are traveling with family members who also have TSA PreCheck, each person needs their own KTN added to their own passenger record.

Frequently Asked Questions

Can I add my KTN after I check in online?

It depends on the airline. Some carriers allow you to add your KTN during online check-in up to 24 hours before departure. Others require you to add it before you check in. Check your airline's website or app to see if the option is available. If it is not, call the airline or add it at the airport, though this may prevent the TSA PreCheck indicator from printing on your boarding pass.

What if I do not have my KTN yet?

You can add it later, even after you have already checked in. Log back into your airline account and update your passenger information. If your flight is within the next few days, call the airline to make sure the change is processed in time. You do not need to rebook or pay any fee.

Will adding my KTN change my seat or ticket price?

No. Adding your KTN is a free update to your passenger information. It does not change your seat, fare, or any other part of your reservation. You are straightforward linking your TSA PreCheck status to your booking.

What if my KTN is wrong on my boarding pass?

If you notice an error before you fly, log back into your airline account and correct it. If you are at the airport, go to the ticket counter and ask them to update it. TSA officers can also verify your KTN at security if your boarding pass does not show it correctly, though having it printed on your pass makes the process smoother.

Do I need to add my KTN to every flight I book?

If you have a frequent flyer account with your airline, you can usually add your KTN to your profile once, and it will automatically appear on all future bookings under that account. If you book as a guest without logging in, you will need to add your KTN to that specific reservation.