How to Add a Known Traveler Number to an Existing Flight Reservation

You can add your KTN to a flight you already booked, but the method depends on which airline you used and when your flight departs

A Known Traveler Number (KTN) is a code that connects your TSA PreCheck, Global Entry, NEXUS, or SENTRI enrollment to your airline reservation. If you booked a flight before you enrolled in one of these programs — or before you added your number to your reservation — you can update it without rebooking. Most airlines let you add or change your KTN through their website, mobile app, or by calling their reservations line. The exact steps vary by carrier, and some airlines require the update at least 24 hours before departure.

Adding your KTN is free and takes only a few minutes. The update does not change your seat, boarding group, or ticket price. Once your KTN is in the system, the airline flags your reservation so TSA knows you are may be able to access for PreCheck screening at the security checkpoint.

Key Takeaways

You can add your KTN to an existing reservation through the airline's website, app, or phone line without paying a change fee.
Your KTN must match exactly what appears in your TSA PreCheck or Global Entry account, including hyphens and spacing.
Most airlines require the update at least 24 hours before departure, though some allow changes closer to flight time.
If you cannot update online, call the airline's reservations number — they can add it while you hold or send you a link to update it yourself.

Adding your KTN through the airline website or app

Log into your airline account using your confirmation number and last name, or your frequent flyer account if you have one. Look for a section labeled "Manage Reservation," "Edit Booking," "Trip Details," or "Passenger Information." Click into the passenger details for the traveler whose KTN you want to add.

You should see a field for "Known Traveler Number," "KTN," "TSA PreCheck Number," or "Trusted Traveler Number." Enter your number exactly as it appears in your TSA PreCheck or Global Entry account — include all hyphens, spaces, and characters. Save the changes. The update usually takes effect when ready, though some airlines process it within a few hours. Check your reservation again after 30 minutes to confirm the number appears in your booking.

Adding your KTN by phone

Call the airline's main reservations line and provide your confirmation number and last name. Tell the agent you want to add your KTN to your reservation. Have your KTN ready — it appears on your TSA PreCheck card, in your TSA PreCheck account online, or in your Global Entry account.

The agent will either add it directly while you wait or send you a link via email to update it yourself. If they add it over the phone, ask them to confirm the number was entered correctly before you hang up. If they send a link, click it within 24 hours and enter your KTN in the same format it appears in your trusted traveler account.

Where to find your KTN

Your KTN is printed on the front of your TSA PreCheck card, usually in the upper right corner. If you do not have the card in front of you, log into your TSA PreCheck account at tsa.gov, click "View process Status," and your KTN will appear on that page. For Global Entry, NEXUS, or SENTRI, log into your account at cbp.gov and find your membership number — this is your KTN for flight reservations.

Write down your KTN exactly as it appears, including any hyphens or spaces. Airlines are strict about matching, and a single character out of place may prevent the number from linking to your reservation.

Timing: when to add your KTN before departure

Most airlines require you to add or update your KTN at least 24 hours before departure. Some carriers allow updates up to 12 hours before departure, and a few accept changes at the airport, though this is not may provide. Check your airline's policy on their website or call reservations to confirm the important date for your specific flight.

If your flight departs in fewer than 24 hours and you have not yet added your KTN, call the airline when ready. Explain that you recently enrolled in TSA PreCheck or Global Entry and want to add your number. The agent may be able to process it as a priority request, though there is no may provide it will be in the system before you reach security.

What happens if you add your KTN too late

If your KTN does not appear in the airline's system before you check in, you will not automatically receive TSA PreCheck benefits on that flight. You can still use your TSA PreCheck card or membership number at the security checkpoint — show your card to the TSA officer, and they can manually verify your status. You will not lose your PreCheck benefits; you straightforward will not have the convenience of the airline flagging your reservation in advance.

For future flights, add your KTN at the time of booking or within 24 hours afterward. This ensures the airline has time to sync your information with TSA before you arrive at the airport.

Fixing a KTN that was entered incorrectly

If you added your KTN but it was entered with a typo or in the wrong format, update it the same way you added it the first time — through the airline website, app, or by calling reservations. You can change it as many times as you need before your flight departs. After you correct it, wait 30 minutes and check your reservation again to confirm the new number appears.

If the airline's system is not accepting your KTN even though you have entered it correctly, call reservations and ask them to verify the number against your TSA PreCheck or Global Entry account. Sometimes the airline's system has a delay syncing with TSA's database, and the agent can flag your reservation manually.

Frequently Asked Questions

Can I add my KTN after I check in online?

Yes. You can add or update your KTN at any time before your flight departs, even after you have checked in online. The update will not change your boarding pass or seat assignment. straightforward log back into your reservation and add the number to your passenger details.

What if I have a connecting flight?

Add your KTN to your entire itinerary at once through the airline's website. If you booked two separate tickets with different airlines, you will need to add your KTN to each reservation separately through each airline's system.

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

Yes. Your KTN is tied to individual reservations, not to your frequent flyer account. You will need to add it each time you book a flight. Some airlines let you set a default KTN in your profile, which will auto-populate when you book, but you should always verify it was added correctly.

What if my KTN changed or I renewed my membership?

If you renewed your TSA PreCheck or Global Entry and received a new KTN, update all your upcoming flight reservations with the new number. Log into each airline reservation and replace the old KTN with the new one. Do this at least 24 hours before each flight.

Will adding my KTN late affect my boarding group or seat?

No. Adding your KTN does not change your boarding group, seat assignment, or any other part of your reservation. It only tells the airline that you have TSA PreCheck so they can flag your record for the security checkpoint.

This guide is for general information only and is not medical, financial, legal, or other professional advice. For decisions specific to your situation, consult a qualified professional. See our Editorial Policy.