You can add your TSA PreCheck number to Delta after you check in, but the process and timing depend on how you checked in

If you checked in online or through the Delta app and forgot to enter your TSA PreCheck number, you can still add it before you reach the airport. If you already checked in at a kiosk or counter, you will need to speak with a Delta agent at the airport to update your reservation. The key is doing this before you go through security — once you are past the TSA checkpoint, the number cannot be added to that flight.

The reason this matters: your TSA PreCheck number must be linked to your specific flight record so the TSA can see it when you scan your boarding pass at security. Adding it after check-in is possible, but the window is narrow, and the method depends on which check-in method you used.

Key Takeaways

  • If you checked in online or via the Delta app, you can log back in and add your TSA PreCheck number up until you reach the airport security line.
  • If you checked in at an airport kiosk or ticket counter, you must visit a Delta ticket counter agent to update your reservation before security.
  • Your TSA PreCheck number must be attached to your flight record before you scan your boarding pass at the TSA checkpoint.
  • Adding the number after check-in takes only a few minutes but requires you to have your confirmation number and TSA PreCheck ID number ready.

Adding TSA PreCheck through the Delta website or app after online check-in

If you checked in through Delta.com or the Delta app, you can return to your reservation and add your TSA PreCheck number without checking in again. Go to Delta.com, select "Manage My Booking," and enter your confirmation number and last name. Once you are in your reservation, look for a section labeled "Passenger Information" or "Known Traveler Number" — the exact wording varies depending on whether you are using the website or app.

Click or tap the field next to your name and enter your TSA PreCheck ID number. This is the nine-digit number that begins with your initials and appears on your TSA PreCheck card. Do not enter your driver's license number or passport number — the system will reject it. After you enter the number, save the changes. The update usually takes effect within seconds, though it can take up to 15 minutes to sync across Delta's systems.

You can do this from home, from your car on the way to the airport, or even from the airport itself — as long as you do it before you reach the TSA security line. Once you scan your boarding pass at security, the update window closes.

Adding TSA PreCheck at the airport if you checked in at a kiosk or counter

If you checked in at an airport kiosk or at the Delta ticket counter, you cannot update your reservation through the website or app. Instead, go to the Delta ticket counter and ask an agent to add your TSA PreCheck number to your flight record. Bring your boarding pass, your TSA PreCheck card (or the ID number), and your government-issued ID.

The agent will pull up your reservation, verify your identity, and manually enter your TSA PreCheck number into the system. This process takes about two to three minutes. The agent will print you a new boarding pass if necessary, though in most cases your existing boarding pass will work once the number is added to the system.

Do this as soon as you arrive at the airport, before you head to security. If the ticket counter is crowded, you may wait 10 to 20 minutes, so plan accordingly. Some airports have dedicated customer service desks separate from the main ticket counter — ask a Delta employee where to go if you are unsure.

What happens if you add the number too late

If you reach the TSA security line before your TSA PreCheck number is added to your flight record, the TSA officer will not see it when they scan your boarding pass. You will go through standard security screening instead of the faster PreCheck line, even if you have an active TSA PreCheck membership.

This does not affect your flight or your TSA PreCheck status — it only means you will remove your shoes, belt, and light jacket, and place your laptop and liquids in a separate bin for that one flight. Your TSA PreCheck membership remains valid for future flights. You can add the number to your return flight or any future Delta flight using the same process.

Common mistakes that prevent the number from being added

The most common error is entering the wrong number. Your TSA PreCheck ID is a nine-digit number that appears on your actual TSA PreCheck card or in your TSA account online. It does not include dashes or spaces — enter it as a continuous string of nine digits. If you enter your driver's license number, passport number, or frequent flyer number by mistake, the system will either reject it or accept it but not link it to TSA PreCheck.

Another mistake is waiting too long. If you are checking in at the airport and realize you forgot your TSA PreCheck number, add it when ready at the ticket counter. Do not wait until you are in the security line or at the gate. Once you scan your boarding pass at the TSA checkpoint, the system locks in your passenger information, and adding the number after that point will not help you on that flight.

A third mistake is confusing your TSA PreCheck number with your Known Traveler Number (KTN) from another program. If you have Global Entry, NEXUS, or SENTRI, your TSA PreCheck number is embedded in that membership, but the field may ask for your "Known Traveler Number" instead. Check your card or your TSA account to find the correct nine-digit number.

If your TSA PreCheck number is not in the system yet

If you recently enrolled in TSA PreCheck and your membership was approved, it can take up to two weeks for your number to appear in the TSA database. During this time, you will not be able to add it to Delta or any other airline. Check your TSA PreCheck status at the TSA website using your process receipt number — it will tell you whether your membership is active.

If your membership is approved but you do not have your physical card yet, you can still use your TSA PreCheck number. The TSA sends the number in your approval email, and you can enter it into Delta's system right away. You do not have to wait for the card to arrive in the mail.

Frequently Asked Questions

Can I add my TSA PreCheck number after I go through security?

No. Once you scan your boarding pass at the TSA checkpoint, your passenger information is locked in for that flight. Adding the number after you pass security will not change your screening experience on that flight. You can add it to future flights using the same process.

Do I need a new boarding pass after adding my TSA PreCheck number?

Usually not. If you added the number through the website or app, your existing boarding pass will work. If a Delta agent added it at the counter, they may print a new one, but it is not required. Either boarding pass will show your TSA PreCheck status at security.

What if I do not have my TSA PreCheck card with me?

You can add your number if you know it. Your TSA PreCheck number appears in your approval email and in your TSA account online. If you do not have it memorized, log into your TSA account from your phone and look it up before you go to the ticket counter or security line.

Will adding my number late cause me to miss my flight?

No. Adding your TSA PreCheck number does not delay your flight or your boarding. It only affects which security line you use. Even if you go through standard screening instead of PreCheck, you will still have time to board as long as you arrive at the airport with enough time before departure.

Can I add my TSA PreCheck number to a flight I already boarded?

No. The number must be added before you scan your boarding pass at security. If you missed the window on a past flight, you can add it to your next Delta flight or any other airline using the same process.