No, you cannot add TSA PreCheck after you check in at the airport

TSA PreCheck is a membership program you must enroll in and pay for before you travel. Once you have checked in for your flight—either at the counter or online—it is too late to join. The TSA PreCheck benefit applies only to flights booked under the membership account you enrolled in, and the airline needs to see your Known Traveler Number (KTN) when you check in to link your reservation to the program.

If you have already checked in without TSA PreCheck, you will go through standard security screening at the airport. You can enroll in TSA PreCheck for future trips, but it will not affect this flight.

Key Takeaways

  • TSA PreCheck enrollment must be completed before you check in for your flight; you cannot add it after checking in.
  • You need a Known Traveler Number (KTN) from your TSA PreCheck membership to link it to your airline reservation during check-in.
  • Enrollment takes about 10 to 15 minutes online, but approval can take several days to a few weeks before your KTN is issued.
  • If you forgot to enroll before your trip, you can still enroll for future flights and will use the expedited security lanes on your next may be able to access trip.

When you need to enroll in TSA PreCheck

You must complete TSA PreCheck enrollment and receive your Known Traveler Number before you book your flight or at least before you check in. The enrollment process happens online through the official TSA PreCheck website (tsa.gov/precheck) and takes about 10 to 15 minutes to fill out. You will provide your name, date of birth, citizenship status, and background information.

After you submit your online process, the TSA reviews your information. This review can take anywhere from a few days to several weeks. Once approved, the TSA issues your Known Traveler Number by email. You then add this number to your airline profile or enter it when you check in for your flight.

How to add your KTN when checking in

If you have your Known Traveler Number before you check in, you can link it to your reservation in two ways. When you check in online through your airline's website or app, there is usually a field labeled "Known Traveler Number" or "KTN" where you enter the nine-character code. If you check in at the airport counter, tell the agent your KTN and they will add it to your reservation.

Once your KTN is linked to your reservation, the TSA will see it when you arrive at security. Your boarding pass will show that you are enrolled in TSA PreCheck, and you will be directed to the expedited security lane where you can keep your shoes, belt, and light jacket on, and leave your laptop and liquids in your bag.

What to do if you forgot to enroll before your trip

If you are already at the airport and realize you do not have TSA PreCheck, you cannot enroll in time for this flight. You will go through standard security screening. However, you can still enroll in TSA PreCheck right now for future trips by visiting tsa.gov/precheck on your phone or computer.

The enrollment fee is $78 to $85 depending on your state, and the membership lasts five years. Once you are approved and receive your KTN, you can use it on every flight you take during those five years. Many employers and credit card companies reimburse the enrollment fee, so check your benefits before paying out of pocket.

The difference between TSA PreCheck and other programs

TSA PreCheck is the most common expedited security program for domestic flights. There is also Global Entry, which includes TSA PreCheck benefits plus expedited customs screening when you return to the United States from international travel. Global Entry costs $100 and lasts five years. If you travel internationally, Global Entry may be worth the extra cost because it covers both domestic and international flights.

Some trusted traveler programs like NEXUS and SENTRI also include TSA PreCheck benefits, but they are designed for specific border crossings. For most domestic travelers, TSA PreCheck is the straightforward choice.

How airlines handle missing KTNs at check-in

If you have TSA PreCheck but forget to add your KTN when you check in, you can still add it at the airport. Go to the airline counter or a kiosk and ask an agent to add your number to your reservation. They can usually do this in a few minutes, and your boarding pass will be updated to show your TSA PreCheck status.

However, if you do not have a KTN yet because you have not enrolled, the airline cannot create one for you. You will need to go through standard security. The TSA PreCheck program is separate from the airline, so only the TSA can issue your number.

Frequently Asked Questions

Can I use TSA PreCheck on a flight I already booked without a KTN?

No. You must have your Known Traveler Number before or during check-in. If you have not enrolled yet, you can still enroll now, but approval takes several days to weeks. If your flight is soon, you may not receive your KTN in time. Enroll anyway so you can use TSA PreCheck on future trips.

What if the TSA website says my process is still pending?

Your process is still under review. You cannot use TSA PreCheck until you receive your Known Traveler Number by email. Check your email (including spam folder) and the TSA PreCheck website regularly. If it has been more than a month, contact the TSA through their website to ask about the status.

Do I need to add my KTN every time I book a flight?

No. Once you add your KTN to your airline frequent flyer account, it will automatically appear on every reservation you make with that airline. If you book through a third-party site or a different airline, you may need to add it manually during check-in.

Can my family member use my TSA PreCheck number?

No. Your Known Traveler Number is tied to your identity and can only be used on your own reservations. Each family member needs their own TSA PreCheck enrollment and KTN. Children under 18 can enroll, and the fee is the same.