What happens when you go through TSA PreCheck screening

TSA PreCheck lets you use a separate, faster security line at the airport. You keep your shoes, belt, and light jacket on. You leave your laptop and liquids bag in your carry-on instead of removing them. You walk through a metal detector instead of a full-body scanner. The whole process usually takes five to ten minutes instead of thirty.

You do not need to do anything special to set up this at the airport. Your membership is tied to your Known Traveler Number (KTN), which is linked to your name and date of birth in the TSA system. When you book a flight, you enter your KTN during checkout. The airline adds it to your reservation. When you arrive at the airport, you show your boarding pass at security, and the TSA officer sees that you are enrolled.

If you have not yet enrolled in TSA PreCheck, you cannot use it at the airport that day. Enrollment happens before your trip, not at security. The process takes four to six weeks from process to approval.

Key Takeaways

  • You must add your Known Traveler Number to your airline reservation when you book your flight, or the TSA PreCheck line will not recognize you.
  • At security, show your boarding pass to the officer directing passengers to lanes; they will send you to the PreCheck line if your KTN is in the system.
  • Keep your shoes, belt, light jacket, and carry-on liquids in your bag during PreCheck screening.
  • If your boarding pass does not show your KTN, you will go through standard screening even if you are enrolled.
  • TSA PreCheck works at most major U.S. airports and on flights with participating airlines, but not all airports or airlines offer it yet.

Adding your Known Traveler Number to your reservation

Your KTN is a nine-character code you receive when your TSA PreCheck enrollment is approved. You find it in your approval email and in your TSA PreCheck account online at universalenroll.dhs.gov.

When you book your flight, enter your KTN in the "Known Traveler Number" field during checkout. Most airlines ask for it on the same page where you enter your name and date of birth. If you book through a travel website like Kayak or Expedia, look for a field labeled "Frequent Traveler Programs" or "TSA PreCheck" and enter it there. The website passes it to the airline.

If you already booked your flight without entering your KTN, log into your airline account and edit your reservation. Go to "Manage My Booking" or "My Trips," find the flight, and look for a section to add or update your KTN. You can do this up to 24 hours before departure. If you are within 24 hours of your flight, call the airline directly and ask them to add it to your reservation.

Your boarding pass will show your KTN once it is in the system. Check your boarding pass before you arrive at the airport. If the KTN does not appear, contact the airline to confirm it was added.

Finding the TSA PreCheck line at security

TSA PreCheck lanes are marked with blue signs that say "TSA PreCheck" or "TSA PreCheck / Clear." They are usually located near the main security checkpoint, sometimes to the left or right of the standard lanes. At some smaller airports, there is only one security lane, and it serves both PreCheck and standard passengers.

When you enter the security area, look for an officer standing near the lane entrances. Show them your boarding pass. If your KTN is in the system, they will direct you to the PreCheck lane. If your boarding pass does not show your KTN, you will be sent to a standard lane even if you are enrolled.

Do not assume you can use the PreCheck line just because you are enrolled. The airline has to add your KTN to your specific reservation. If it is missing, you go through standard screening.

What to do at the TSA PreCheck checkpoint

Place your carry-on bag on the conveyor belt. You do not need to remove your laptop, tablet, or liquids bag from your carry-on. Leave them inside. Remove your boarding pass and ID and place them on top of your bag or hold them in your hand.

Keep your shoes, socks, belt, and light jacket on. A light jacket means a thin sweater or blazer. A heavy winter coat should come off. Keep your keys, phone, and wallet in your pocket or bag.

Walk through the metal detector. If you set it off, you will be asked to step aside for additional screening, which may include a pat-down or a swab of your hands. This happens occasionally and does not mean anything is wrong.

Collect your bag and ID on the other side of the detector. Put your shoes back on if you removed them, and move to the side to gather your things before you leave the security area.

TSA PreCheck at different airports and airlines

TSA PreCheck works at most major U.S. airports, including Atlanta, Los Angeles, Chicago, Dallas, New York (all three airports), Denver, and San Francisco. Smaller regional airports may not have a dedicated PreCheck lane. Call your airport's TSA office or check the airport website before your trip if you are flying out of a smaller city.

TSA PreCheck lanes are available only on flights with participating airlines. Major carriers like American, Delta, United, Southwest, Alaska, and JetBlue participate. Some regional carriers and budget airlines do not. If your airline does not participate, you cannot use PreCheck even if you are enrolled and your KTN is in your reservation.

Check the TSA website at tsa.gov/precheck to see the full list of participating airports and airlines. The list changes occasionally as new airports and airlines join the program.

What to do if your boarding pass does not show your KTN

If you added your KTN to your reservation but your boarding pass does not display it, contact your airline before you go to the airport. Call their customer service line or use their app or website to check your reservation. Ask them to confirm that your KTN is in the system.

If the airline says your KTN is there but your boarding pass still does not show it, ask them to reissue your boarding pass. Sometimes the system needs a few minutes to update. If you are at the airport, go to the airline ticket counter and ask them to print a new boarding pass with your KTN included.

If your KTN is not in your reservation at all, you will go through standard security screening. You cannot use the PreCheck line without it in the system, even if you have an active TSA PreCheck membership.

International flights and TSA PreCheck

TSA PreCheck works for the security checkpoint before you board a domestic flight. It does not work at international airports outside the United States or for screening when you arrive in another country.

If you are flying from a U.S. airport to another country, you use TSA PreCheck to get through U.S. security. When you land abroad, you go through that country's immigration and security screening, which has its own rules and lines.

If you are flying from another country back to the United States, you do not use TSA PreCheck at the foreign airport. You go through that country's security. When you land in the U.S., you go through U.S. Customs and Border Protection, not TSA PreCheck.

Frequently Asked Questions

What if I forget to add my KTN when I book my flight?

Log into your airline account and edit your reservation to add it. You can do this up to 24 hours before departure. If you are within 24 hours of your flight, call the airline directly. They can add it over the phone and reissue your boarding pass. Without your KTN in the system, you cannot use the PreCheck line.

Do I need to print my boarding pass or can I use my phone?

Either works. Show the TSA officer your boarding pass on your phone or a printed copy. The officer needs to see your KTN on the pass to send you to the PreCheck line. Make sure your phone has enough battery to display it clearly.

Can my family members use my TSA PreCheck membership?

No. TSA PreCheck is tied to one person's name, date of birth, and fingerprints. Each family member needs their own enrollment and their own KTN. Children under 12 can go through the PreCheck line with a parent or guardian who is enrolled, but they do not need their own membership.

What happens if I use someone else's KTN on my boarding pass?

The TSA officer will see that the KTN does not match your name and ID. You will be sent to standard security screening. Using someone else's information can result in fines or other penalties.

Do I lose TSA PreCheck if I do not use it for a while?

No. Your membership stays active for five years from the date you were approved. You do not have to use it on every flight. As long as you keep adding your KTN to your reservations when you fly, you can use the PreCheck line whenever it is available.