You can add TSA PreCheck to an existing Delta reservation, but the process depends on whether you already have an active PreCheck membership

If you have a valid TSA PreCheck membership, you can link it to your Delta booking through your online account or by calling Delta directly. If you do not yet have PreCheck, you will need to enroll separately before adding it to your reservation — Delta cannot process the membership process for you.

The fastest route is to add your Known Traveler Number (KTN) to your reservation yourself through Delta's website or app. This takes about five minutes and costs nothing if you already hold an active membership. If you do not have PreCheck yet, you will need to complete the enrollment process through the official TSA PreCheck program first, which involves an process fee and an in-person appointment.

Key Takeaways

  • You can add an existing TSA PreCheck membership to a Delta reservation at any time before your flight by entering your Known Traveler Number in your booking.
  • If you do not yet have TSA PreCheck, you must enroll through the official TSA PreCheck program separately — Delta does not handle memberships or applications.
  • Adding your KTN to your reservation is free and takes minutes through Delta's website, app, or by phone.
  • Your PreCheck benefit will appear on your boarding pass once your KTN is linked and the reservation is updated in the system.

Adding your Known Traveler Number to an existing Delta booking

Log into your Delta account on the website or open the Fly Delta app, then find the reservation you want to update. Look for a section labeled "Manage My Booking" or "Trip Details." Once you open your reservation, you should see a field for "Known Traveler Number" or "KTN" — this is where you enter your TSA PreCheck number.

Type your KTN exactly as it appears on your TSA PreCheck approval letter or membership card. Delta will save the change when ready. Your boarding pass will update to show your PreCheck status once the system processes the change, which usually happens within a few minutes but can take up to 24 hours.

If you cannot find the KTN field online, call Delta reservations at 1-800-221-1212 and give the agent your confirmation number and your Known Traveler Number. They can add it to your reservation over the phone.

What happens after you add your KTN to Delta

Once your Known Traveler Number is linked to your reservation, your boarding pass will display a TSA PreCheck indicator — usually a checkmark or the words "TSA PreCheck" printed on the pass. This tells the TSA officer at security that you are enrolled in the program.

You will then be able to use TSA PreCheck lanes at the airport, where you can keep your shoes, belt, and light jacket on, leave your laptop and liquids in your carry-on bag, and move through security faster. The benefit applies to the specific flight you added the KTN to, so if you have other Delta flights booked without the number, you will need to add it to those reservations separately.

Getting TSA PreCheck if you do not have it yet

TSA PreCheck membership is a separate process from booking a flight. You cannot purchase or enroll through Delta — you must go through the official TSA PreCheck program directly. The membership costs $78 to $85 depending on your state and covers five years of benefits.

To enroll, visit the TSA PreCheck website or use the official TSA PreCheck mobile app. You will answer security questions, provide your personal information, and pay the enrollment fee online. After that, you will schedule an in-person appointment at a TSA PreCheck enrollment center or an approved partner location (many airports, some UPS stores, and some pharmacies offer appointments). At your appointment, a TSA officer will verify your identity and take your fingerprints. The whole process usually takes four to six weeks from process to approval.

Once you receive your approval notice and your Known Traveler Number, you can then add that number to any existing or future Delta reservations.

Adding your KTN to Delta flights booked through a travel agent or third-party site

If you booked your Delta flight through a travel website like Expedia, Kayak, or Costco Travel, or through a travel agent, you still need to add your KTN directly to Delta. Log into your Delta account using your confirmation number and last name, or call Delta reservations. The airline will have your booking in their system even if you purchased through another site.

Some third-party booking sites have their own KTN fields, but adding it there does not may provide it will transfer to Delta's system. To be certain your PreCheck benefit shows on your boarding pass, add your number through Delta directly.

Timing: when to add your KTN before your flight

You can add your Known Traveler Number to your Delta reservation at any point — months in advance or the day before your flight. However, it is best to add it as soon as you have your TSA PreCheck membership, because the change needs time to sync through Delta's system and appear on your boarding pass.

Add your KTN at least 24 hours before your flight to be safe. If you add it closer to departure, check your boarding pass online or through the app before you go to the airport to confirm the PreCheck indicator is showing. If it is not there and your flight is within a few hours, call Delta reservations when ready so an agent can manually verify the change in the system.

What to do if your KTN does not appear on your boarding pass

If you added your Known Traveler Number to your Delta reservation but it is not showing on your boarding pass, first check that you typed the number correctly. Log back into your reservation and verify the KTN matches your TSA PreCheck approval letter exactly — even a single wrong digit will cause the system to reject it.

If the number is correct, wait a few more hours for the system to update. If your flight is tomorrow or later, the change should appear by then. If your flight is today or in a few hours and the PreCheck indicator still is not on your boarding pass, call Delta reservations at 1-800-221-1212 before you leave for the airport. An agent can check whether the KTN is in the system and may be able to manually add it to your boarding pass.

Frequently Asked Questions

Can I add TSA PreCheck to a Delta flight I booked years ago but am flying soon?

Yes. As long as your TSA PreCheck membership is still active, you can add your Known Traveler Number to any existing Delta reservation, no matter when you booked it. Log into your Delta account, find the reservation, and enter your KTN in the trip details.

Do I have to pay Delta to add my TSA PreCheck number to my reservation?

No. Adding your Known Traveler Number to a Delta booking is free. You only pay for TSA PreCheck membership itself, which is a separate enrollment through the TSA PreCheck program.

What if I have TSA PreCheck but Delta does not recognize my KTN?

Check that you typed your Known Traveler Number exactly as it appears on your TSA PreCheck approval letter — spaces and hyphens matter. If the number is correct, wait 24 hours for the system to update. If it still does not work, call Delta at 1-800-221-1212 and have your TSA PreCheck approval letter handy so an agent can verify the number in their system.

Can I add TSA PreCheck to a Delta flight booked for someone else?

Only the passenger on the reservation can add their own Known Traveler Number. If you booked a flight for a family member or friend, they will need to log into their own Delta account using the confirmation number and add their KTN themselves. You cannot add another person's PreCheck number to their ticket.

Will adding my KTN to Delta change my ticket price or seat assignment?

No. Adding your Known Traveler Number does not change your fare, your seat, or any other part of your reservation. It only updates your boarding pass to show that you are enrolled in TSA PreCheck.