What TSA PreCheck Does at Security

TSA PreCheck is a program that lets you go through a faster security line at the airport. When you have PreCheck, you keep your shoes, belt, and light jacket on, leave your laptop and liquids bag in your carry-on, and walk through standard metal detectors instead of full-body scanners. You still go through security screening—nothing is skipped—but the process moves faster because you remove fewer items.

PreCheck works at over 200 U.S. airports and is available on most domestic flights. You need to enroll in the program first, which involves an process, a background check, and an in-person appointment at an enrollment center. Once you are enrolled, you use your Known Traveler Number (KTN) when you book flights, and the TSA will recognize you at security.

Key Takeaways

  • PreCheck enrollment requires an process, background check, and appointment at an enrollment center, and costs $78 to $85 for five years.
  • You must add your Known Traveler Number to your airline reservation before each flight for PreCheck to work at security.
  • At PreCheck security lanes, you keep shoes, belt, and light jacket on, and leave laptops and liquids in your bag.
  • PreCheck is available at over 200 U.S. airports but only on domestic flights; international flights do not use PreCheck lanes.

Adding Your Known Traveler Number to Your Reservation

Your Known Traveler Number (KTN) is a nine-character code you receive after you complete your PreCheck enrollment. This number tells the airline and TSA that you are enrolled in the program. You must add it to your airline reservation before you check in for your flight, or the TSA will not recognize you as a PreCheck member at security.

When you book your flight online, look for a field labeled "Known Traveler Number," "KTN," or "TSA PreCheck" in the passenger information section. Enter your nine-character code exactly as it appears on your PreCheck approval notice. If you are booking by phone, give the airline your KTN when you provide your name and flight details. If you forget to add it during booking, you can usually add it through your airline's website or mobile app up until check-in, though some airlines have earlier cutoff times.

Different airlines store this information differently. Some airlines save your KTN to your frequent flyer account so it carries over to future bookings automatically; others require you to enter it for each reservation. Check your airline's website to see if you can save your KTN to your profile.

What to Expect in the PreCheck Security Lane

When you arrive at security, look for signs that say "TSA PreCheck" or "PreCheck" above certain lanes. These lanes are usually shorter and move faster than standard security lines. Walk to a PreCheck lane and have your boarding pass and ID ready. The TSA officer will scan your boarding pass to confirm your PreCheck status.

Once you are in the PreCheck lane, you can keep your shoes, socks, belt, and light jacket or cardigan on. Remove your watch and any large metal items from your pockets. Open your carry-on bag and leave your laptop, tablet, and liquids bag inside—you do not need to remove them. Place your carry-on and personal item on the conveyor belt. Walk through the metal detector (not a full-body scanner). Collect your items on the other side and move to your gate.

The entire process typically takes 5 to 10 minutes, compared to 15 to 30 minutes in standard security lines during busy travel times. PreCheck does not may provide you will skip the full-body scanner or pat-down—the TSA can still direct you to additional screening if something triggers an alarm—but this happens less often in PreCheck lanes.

When PreCheck Does Not Work

PreCheck only works on domestic flights within the United States. If you are flying internationally, you will go through standard security screening even if you have PreCheck. Some airports also do not have PreCheck lanes; in those cases, you will go through regular security even with a valid KTN. Check the TSA website for a list of airports that offer PreCheck before you travel.

If your boarding pass does not show a "TSA Pre✓" indicator next to your name, you will not be able to use the PreCheck lane. This usually means your KTN was not added to your reservation, or the airline did not transmit it correctly to the TSA. If this happens, ask a TSA officer at security whether you can still use the PreCheck lane; some officers will let you through if you can show your PreCheck approval letter or membership card, but this is not may provide.

PreCheck status also does not carry over to connecting flights on different airlines. If you have a connection, make sure your KTN is added to both flight reservations.

Renewing Your PreCheck Membership

PreCheck membership lasts five years from your enrollment date. About nine months before your membership expires, you will receive a notification from the TSA. You can renew online through the TSA's official website without visiting an enrollment center, which takes about 10 minutes. The renewal fee is the same as the initial enrollment fee.

If you renew online, your existing KTN stays the same, and you do not need to update your airline profiles. If you wait until after your membership expires, you will need to enroll again from the beginning, which requires a new appointment and a new background check. It is easier to renew before your membership runs out.

Troubleshooting Common Problems

If your PreCheck is not working at security, the most common reason is that your KTN was not added to your reservation. Check your airline confirmation email to see if "TSA Pre✓" appears next to your name. If it does not, log into your airline account and add your KTN manually. Some airlines require you to add it at least 24 hours before your flight.

If you added your KTN but it still does not show on your boarding pass, contact your airline's customer service before you go to the airport. They can confirm whether your KTN was entered correctly and update your reservation if needed. Bring your PreCheck approval letter or membership card to the airport as backup proof of enrollment.

If you are at security and the TSA officer says your PreCheck is not valid, ask them to check your KTN manually. Sometimes the system has a delay, especially if you enrolled recently or renewed your membership. The officer can look up your status in the TSA database using your ID and KTN.

Frequently Asked Questions

Do I have to use PreCheck every time I fly?

No. PreCheck is optional. Even if you are enrolled, you can choose to go through standard security instead. However, you will not get the faster screening unless you add your KTN to your reservation and use a PreCheck lane.

What if I lose my PreCheck membership card?

Your membership card is not required to use PreCheck. The TSA identifies you through your KTN in the airline reservation system. If you lose your card, you can request a replacement through the TSA website, but you do not need it to go through PreCheck security.

Can I use PreCheck if I am traveling with children?

Children under 12 can go through PreCheck lanes with an adult who has PreCheck, even if the child is not enrolled. Children 12 and older must have their own PreCheck membership to use the PreCheck lane. Infants do not need PreCheck.

Will PreCheck work if I change my name?

If you legally change your name, you should update your PreCheck membership through the TSA website. Your KTN stays the same, but your name in the system needs to match your ID. Contact the TSA to update your profile before your next flight.

What happens if I forget to add my KTN before I check in?

You can usually add your KTN through your airline's app or website up until check-in, though some airlines have earlier cutoffs. If you miss the important date, you will go through standard security. For future flights, add your KTN as soon as you book.