Add Your TSA PreCheck Number During Booking or in Your Profile

You add your TSA PreCheck number to Southwest by entering it in your passenger profile before you book a flight, or by adding it to an existing reservation. Southwest calls this your Known Traveler Number (KTN). The airline uses this number to match you with your TSA PreCheck status at check-in, so security knows to send you to the shorter PreCheck line.

You can enter your KTN in two places: when you first create your Southwest account, or later in your profile settings. If you already have a Southwest account without your TSA PreCheck number, you can add it anytime—it will explore to future bookings and any reservations you have not yet checked in for.

Your TSA PreCheck number is the 10-digit identifier you received when you were approved for the program. It appears on your approval notice and on your actual TSA PreCheck card or ID. Do not confuse it with your confirmation number for a flight—they are different things.

Key Takeaways

  • Your TSA PreCheck number is a 10-digit code that you enter into Southwest's system as your Known Traveler Number (KTN).
  • You can add your KTN when you create a new Southwest account, or update an existing account in your profile settings at any time.
  • Once your KTN is in your Southwest profile, it automatically applies to all future bookings under that account.
  • If you book a flight before adding your KTN, you can still add it to that reservation up until you check in online or at the airport.

Add Your KTN When Creating a New Southwest Account

When you sign up for a new Southwest account, the airline asks for your Known Traveler Number during the account setup. Look for a field labeled "Known Traveler Number (KTN)" or "TSA PreCheck Number." Enter your 10-digit TSA PreCheck number exactly as it appears on your approval notice or card. If you do not have your TSA PreCheck number yet, you can skip this step and add it later.

After you finish creating your account, your KTN is saved to your profile. From that point forward, every flight you book through Southwest will automatically include your TSA PreCheck status, and the airline will display a TSA PreCheck indicator on your boarding pass.

Add Your KTN to an Existing Southwest Account

If you already have a Southwest account, log in and go to your profile or account settings. The exact location varies slightly depending on whether you are using the Southwest website or the mobile app, but both have a section for passenger information or travel preferences.

On the Southwest website, click your name in the top right corner, then select "My Account" or "Profile." Look for a section called "Passenger Information" or "Known Traveler Number." Click the option to add or edit your KTN, enter your 10-digit TSA PreCheck number, and save the changes.

In the Southwest mobile app, tap the menu icon (three horizontal lines), select "My Account," then find "Passenger Information" or "Known Traveler Number." Enter your number and save. Once you have saved your KTN, it applies to all future bookings and any existing reservations you have not yet checked in for.

Add Your KTN to a Specific Flight Reservation

If you have already booked a Southwest flight and did not include your TSA PreCheck number, you can still add it to that reservation. Go to Southwest's website or app, find your reservation using your confirmation number and name, and look for an option to edit passenger information or add a Known Traveler Number.

You can make this change up until you check in for your flight—either online (24 hours before departure) or at the airport. Once you check in, the boarding pass is locked and you cannot add your KTN to that specific flight. If you miss the window, your TSA PreCheck status will not show on that boarding pass, but you can still go through PreCheck screening if you show your TSA PreCheck card or ID at security.

What Happens After You Add Your KTN

After your KTN is in your Southwest account, the airline sends it to the TSA before your flight. The TSA matches your name and number against its PreCheck database. If everything matches, your boarding pass will display a TSA PreCheck indicator—usually a small TSA logo or the words "TSA PreCheck" printed on your pass.

When you arrive at security, show your boarding pass and a valid ID. The TSA agent will see the PreCheck indicator and direct you to the PreCheck line, where you can keep your shoes, belt, and light jacket on, and leave your laptop and liquids in your carry-on bag. The process is faster than standard screening.

If your boarding pass does not show the TSA PreCheck indicator but you have an active TSA PreCheck membership, bring your TSA PreCheck card or ID to the security checkpoint. The agent can manually verify your status and send you to the PreCheck line even without the indicator on your pass.

Common Mistakes to Avoid

The most common error is entering your TSA PreCheck number incorrectly. Double-check that you have typed all 10 digits exactly as they appear on your approval notice or card. Even one wrong digit will prevent the TSA from matching your record, and you will not get the PreCheck indicator on your boarding pass.

Another mistake is assuming that adding your KTN to your Southwest account automatically updates past reservations. It does not. Your KTN applies to new bookings and existing reservations you have not checked in for, but flights you booked before adding your number will not show the PreCheck indicator unless you manually edit that specific reservation.

Do not confuse your TSA PreCheck number with your Southwest confirmation number. Your confirmation number is a six-character code Southwest gives you when you book a flight. Your KTN is your 10-digit TSA PreCheck identifier. Southwest needs both, but they go in different fields.

Frequently Asked Questions

Where do I find my TSA PreCheck number?

Your TSA PreCheck number is on the approval notice you received when you were accepted into the program. It is also printed on your TSA PreCheck card or ID if you received a physical card. The number is 10 digits long. If you cannot find it, log into your TSA PreCheck account at tsa.gov to view your approval details.

Can I add my TSA PreCheck number after I have already booked a Southwest flight?

Yes. You can add your KTN to an existing reservation anytime before you check in. Once you check in online or at the airport, the boarding pass is locked and you cannot edit it. If you miss that window, bring your TSA PreCheck card to the security checkpoint and the agent can verify your status manually.

What if my boarding pass does not show the TSA PreCheck indicator even though I added my number?

This usually means the TSA could not match your name and number in its database. Check that you entered your KTN correctly—even one wrong digit will cause a mismatch. If the number is correct, bring your TSA PreCheck card or ID to security and show it to the agent. They can verify your status and send you to the PreCheck line.

Do I need to add my TSA PreCheck number to every Southwest flight?

No. Once you add your KTN to your Southwest account, it automatically applies to all future bookings made under that account. You only need to add it once. If you book a flight before adding your number, you can edit that specific reservation to include it.

Can I use TSA PreCheck on Southwest if my number is not on my boarding pass?

Yes. Even if your boarding pass does not display the TSA PreCheck indicator, you can still use PreCheck screening if you have an active TSA PreCheck membership. Show your TSA PreCheck card or ID at the security checkpoint, and the agent will verify your status and direct you to the PreCheck line.