Link your TSA PreCheck number to Southwest during booking or after

You add TSA PreCheck to Southwest by entering your Known Traveler Number (KTN) when you book a flight or by adding it to an existing reservation. Southwest does not issue TSA PreCheck itself — you obtain that through the TSA's official program — but once you have your KTN, linking it to your Southwest account takes about two minutes and appears on your boarding pass at check-in.

The KTN is a nine-character code you receive when TSA PreCheck approves your process. You can add it during the initial booking process, after you have booked but before you fly, or even at the airport, though doing it beforehand is simpler and ensures it prints on your pass.

Key Takeaways

  • Your TSA PreCheck KTN is a nine-character code issued by the TSA, separate from your Southwest confirmation number or frequent flyer account.
  • You can enter your KTN when booking a Southwest flight, or add it afterward through your reservation under the "Passenger Information" section.
  • Adding your KTN to Southwest does not cost extra and does not change your fare — it only links your PreCheck status to that specific flight.
  • Your KTN must be entered exactly as it appears on your TSA PreCheck approval letter, including any spaces or hyphens.

Add your KTN during Southwest booking

When you book a flight on Southwest's website or mobile app, you reach a page asking for passenger details. This page includes a field labeled "Known Traveler Number" or "KTN" — it often appears near the name and date of birth fields. Enter your nine-character KTN exactly as it appears on your TSA PreCheck approval documentation.

If you book by phone through Southwest's reservations line at 1-800-I-FLY-SWA, the agent will ask whether you have a KTN and will enter it into your reservation. Providing it at booking means your boarding pass will display your PreCheck status, which the TSA agent at security will see and use to direct you to the PreCheck lane.

Add your KTN to an existing Southwest reservation

If you already booked a flight without entering your KTN, you can add it afterward. Go to Southwest's website, select "Manage Reservations," and enter your confirmation number and name. Once your reservation appears, look for a link or button labeled "Passenger Information" or "Edit Passenger Details."

Click that option and find the KTN field. Enter your nine-character number, save the changes, and your boarding pass will update to reflect your PreCheck status. You can do this at any time before your flight, though doing it at least a day before departure gives you time to confirm the change took effect.

Where to find your TSA PreCheck KTN

Your KTN appears on the approval letter you received from the TSA when your PreCheck process was processed. If you completed your process online through the TSA's official website at tsa.gov, you can also log into your account there and view your KTN in your profile.

The KTN is not the same as your TSA PreCheck membership number or your frequent flyer account number. It is a separate nine-character identifier used specifically for linking your PreCheck status to airline reservations. If you cannot locate it, contact the TSA directly at 1-855-347-8371 or check your email for the original approval message.

What happens after you add your KTN to Southwest

Once your KTN is linked to your reservation, your Southwest boarding pass will show a TSA PreCheck indicator — usually a small mark or the letters "TSA Pre" printed on the pass. When you arrive at security, show this boarding pass to the TSA agent. They will direct you to the PreCheck screening lane, where you can leave shoes, belts, and light jackets on, keep laptops and liquids in your bag, and move through the line faster than standard screening.

Adding your KTN to Southwest does not change your ticket price, seat assignment, or any other part of your reservation. It is purely informational and tells the TSA that you have completed their background check and vetting process.

Common mistakes when entering your KTN

The most frequent error is typing your KTN incorrectly — even a single wrong character will prevent the TSA from recognizing your PreCheck status at security. Copy and paste your KTN directly from your approval letter or TSA account rather than typing it by hand. Pay attention to spaces or hyphens; some KTNs include them and some do not, and they must match exactly.

Another common mistake is confusing your KTN with your frequent flyer number or confirmation number. These are three different codes. Your KTN is the one the TSA issued, and it is the only one that matters for PreCheck screening. If you are unsure which number is your KTN, check your TSA approval letter — it will be clearly labeled.

Adding your KTN to your Southwest frequent flyer profile

Beyond adding your KTN to individual reservations, you can also store it in your Southwest Rapid Rewards frequent flyer account. Log into your account on Southwest's website, go to "Account Settings" or "Profile," and look for a section labeled "Travel Information" or "Trusted Traveler Programs." Enter your KTN there, and Southwest will automatically populate it on future bookings under that account.

This saves time if you fly Southwest regularly. Every time you book a flight while logged into your Rapid Rewards account, your KTN will already be filled in. You can still edit or remove it for any specific reservation if needed.

Frequently Asked Questions

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

No. If you store your KTN in your Rapid Rewards profile, Southwest will add it automatically to every booking you make under that account. If you do not have a frequent flyer account or prefer not to store it there, you can add it manually to each reservation, but you only need to do it once per booking.

What if I do not have a TSA PreCheck KTN yet?

You must obtain TSA PreCheck through the TSA's official program first. Visit tsa.gov or find an enrollment center near you. The process involves an process, background check, and in-person appointment. Once approved, you will receive your KTN, which you can then add to Southwest.

Can I add my KTN at the airport if I forgot to do it online?

Yes. You can provide your KTN to a Southwest agent at the ticket counter when you check in, and they can add it to your reservation before your boarding pass prints. However, doing it online beforehand is faster and ensures your PreCheck status appears on your pass from the start.

Will adding my KTN to Southwest cost me anything?

No. Linking your KTN to a Southwest reservation is free. You paid for TSA PreCheck when you enrolled in the program, but adding it to airline reservations has no additional charge.

What if my boarding pass does not show TSA PreCheck after I added my KTN?

Double-check that you entered your KTN correctly and that it matches your approval letter exactly. If it does, wait a few hours and check again — sometimes the system takes time to update. If it still does not appear, contact Southwest at 1-800-I-FLY-SWA or visit a ticket counter before your flight to have an agent verify the entry.