Add your TSA PreCheck number directly in the Southwest app

To add TSA PreCheck to your Southwest Airlines account, open the Southwest app, go to your profile or account settings, find the "Known Traveler Number" or "KTN" field, and enter your nine-digit TSA PreCheck number. The app will save it to your account, and it will appear on your boarding pass when you check in for a flight. You do not need to contact Southwest or TSA — the connection happens automatically once the number is in the system.

Your TSA PreCheck number is printed on your actual TSA PreCheck card. It is a nine-digit code that starts with your initials or a letter. If you have already received your card in the mail after your TSA PreCheck appointment, you have everything you need to add it right now.

Key Takeaways

  • Your TSA PreCheck number appears on your physical TSA PreCheck card and is nine digits long.
  • The Southwest app stores your TSA PreCheck number in your profile under Known Traveler Number, and it automatically shows on your boarding pass.
  • You can add or update your TSA PreCheck number anytime, even after you have already booked a flight.
  • If your boarding pass does not show TSA PreCheck after you add the number, wait a few hours and refresh the app, or contact Southwest support to confirm the number was saved correctly.

Where to find your TSA PreCheck number

Your TSA PreCheck number is printed on the front of your physical TSA PreCheck card, usually in the upper right corner. It is a nine-digit code. If you have not received your card yet, you cannot add the number to the app — you must wait for the card to arrive by mail. TSA typically mails cards within two weeks of your appointment, though timing varies.

If you have lost your card or cannot find the number, you can look it up on the TSA website by signing into your TSA PreCheck account at tsa.gov. Log in with the same email and password you used when you scheduled your appointment. Your Known Traveler Number will be listed in your account dashboard.

Step-by-step: adding the number in the Southwest app

On iPhone or iPad: Open the Southwest app and tap the profile icon (usually in the bottom right corner). Select "Account" or "Profile Settings." Look for a field labeled "Known Traveler Number" or "KTN." Tap into that field and type your nine-digit TSA PreCheck number. Tap "Save" or "Done." The app will confirm the number has been saved.

On Android: Open the Southwest app and tap the menu icon (three horizontal lines) or your profile icon. Select "Account" or "Profile Settings." Find the "Known Traveler Number" field. Enter your nine-digit TSA PreCheck number and tap "Save." The app will confirm the update.

On the Southwest website: Log into southwest.com, go to "My Account," select "Profile," and look for "Known Traveler Number." Enter your TSA PreCheck number and save the changes. The number will sync to your app within a few hours.

When the TSA PreCheck number appears on your boarding pass

Once you have added your TSA PreCheck number to your Southwest account, it will show on your boarding pass the next time you check in for a flight — either online, in the app, or at the airport. You do not need to do anything else. The number stays linked to your account for all future flights.

If you check in before adding the number, your boarding pass will not show TSA PreCheck. You can add the number after checking in, but it will not update that boarding pass. For your next flight, the number will appear automatically when you check in again.

What to do if the number does not appear on your boarding pass

If you have added your TSA PreCheck number but it is not showing on your boarding pass, first wait a few hours and refresh the app. Sometimes the system takes time to sync. Close the Southwest app completely and reopen it, then check your boarding pass again.

If the number still does not appear, contact Southwest customer service by phone, chat, or the app's help section. Have your TSA PreCheck card handy so you can confirm the nine-digit number is correct. Southwest can verify that the number was saved to your account and troubleshoot why it is not displaying on your boarding pass. It is also worth double-checking that you entered the number exactly as it appears on your card — even one wrong digit will prevent it from working.

Updating or changing your TSA PreCheck number

If you renew your TSA PreCheck or receive a new card with a different number, you can update it in the Southwest app the same way you added it the first time. Go to your profile, find the Known Traveler Number field, delete the old number, and enter the new one. Save the changes.

Your old TSA PreCheck number will stop working on new boarding passes once you update it. If you have already checked in for a flight with the old number, that boarding pass will not change — but all future check-ins will use the new number.

Frequently Asked Questions

Do I have to add my TSA PreCheck number to fly with Southwest?

No. You can fly without adding it to the app. However, adding it ensures TSA PreCheck appears on your boarding pass, which tells TSA agents at security that you have already been vetted. Without it on your boarding pass, you may not receive TSA PreCheck screening benefits even though you have an active membership.

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

Yes. You can add or update your TSA PreCheck number anytime, even after you have booked. Just add it to your profile before you check in for your flight, and it will appear on your boarding pass.

What if I have not received my TSA PreCheck card yet?

You cannot add the number until your card arrives. TSA mails cards within two weeks of your appointment. Once it arrives, you can add the number when ready. If you are traveling before your card arrives, you will not be able to use TSA PreCheck for that trip.

Will adding my TSA PreCheck number to Southwest cost anything?

No. Linking your number to your Southwest account is free. You already paid for TSA PreCheck when you completed your appointment and background check. Southwest does not charge a fee to store the number in your profile.

Can I use the same TSA PreCheck number on other airlines?

Yes. Your TSA PreCheck number works with every airline. You can add it to American, Delta, United, and any other carrier the same way you added it to Southwest. The number itself never changes — only the airline's system where you store it.