What Is a Known Traveler Number (KTN)?

TL;DR

A Known Traveler Number (KTN) is the 9-digit code TSA issues when your TSA PreCheck application is approved. You add it to airline reservations so “TSA PRE✓” prints on your boarding pass and you can use the fast lane. If you have Global Entry, your PASSID works as a KTN.

At a glance

• What it is: A unique 9-digit identifier issued by TSA after PreCheck approval
• Where to find it: TSA UEC dashboard at tsa.gov, or your original approval email
• How to use it: Add to your airline profile or individual reservations in the “Known Traveler Number” field
• Global Entry: Uses a PASSID — enters the same KTN field, activates PreCheck too
• If PreCheck doesn’t print: Check name-match, KTN accuracy, and membership status

Why your KTN matters

Getting approved for TSA PreCheck is only half the job. The KTN is the link between your TSA approval and your airline reservation. Without it on your booking, TSA’s system has no way to know you’re a vetted traveler, and the “TSA PRE✓” indicator won’t appear on your boarding pass.

Many people get approved, receive their KTN, and then never quite figure out how to connect it to their reservations — and end up in the standard security line wondering why PreCheck isn’t working. This guide fixes that.

What a Known Traveler Number looks like

A KTN is exactly 9 digits. It looks like: 123456789

It isn’t an account number, a confirmation number, or a barcode. It’s a fixed identifier attached to your identity in the TSA Secure Flight system. Once assigned, it doesn’t change — renewing your PreCheck membership keeps the same KTN.

Don’t confuse it with your:

• TSA UEC login credentials (email + password for the dashboard)
• Application reference number (the tracking ID you used to check approval status)
• Redress Number (a separate DHS number for travelers who’ve been flagged by mistake)

Where to find your KTN

Option 1: TSA UEC dashboard

Go to tsa.gov/precheck and log into your account. Your KTN appears on the membership overview page.

Option 2: Original approval email

When TSA approved your enrollment, they sent an email with your KTN. Search your inbox for “TSA PreCheck” or “Known Traveler Number.”

Option 3: Physical approval letter

If you requested paper mail during enrollment, your KTN was on the approval letter. Some enrollment providers (IDEMIA, Telos) also send a card with your membership details.

Option 4: If you have Global Entry — use your PASSID

If you’re a Global Entry member, your PASSID is your trusted-traveler number. It’s printed on the back of your Global Entry card (CBP Trusted Traveler card). Enter that 9-digit number in the KTN field on airline reservations — it activates PreCheck on your boarding pass automatically, because Global Entry includes PreCheck.

The PASSID and the TSA-issued KTN are different numbers from different programs, but both go in the same airline KTN field. Don’t try to enroll in PreCheck separately if you already have Global Entry — you already have the benefit.

How to add your KTN to airline reservations

Save it to your airline loyalty profile (recommended)

The most reliable approach is to store your KTN in your frequent flyer profile once. Every future reservation you make while logged in will inherit it automatically.

Where to find it in major airline profiles:

• American Airlines AAdvantage: My Account → Personal Information → Known Traveler Number
• Delta SkyMiles: My Profile → Personal Information → Known Traveler #
• United MileagePlus: My Profile → Personal Details → TSA Pre✓ / Known Traveler Number
• Southwest Rapid Rewards: My Account → Personal Info → Known Traveler Number
• JetBlue TrueBlue: Manage Account → Traveler Information → Known Traveler Number

Adding it once covers all future bookings on that airline.

Add it to an individual reservation

If you already have a booking and need to add the KTN:

1. Log into the airline’s website and go to “Manage Trip” or “My Trips.”
2. Find the reservation and look for “Passenger Details” or “Edit traveler info.”
3. Enter your KTN in the Known Traveler Number field.
4. Save and re-check your boarding pass.

Changes to individual reservations should reflect on your boarding pass within a few hours, though some airlines refresh only at check-in.

At check-in

If you forgot to add your KTN beforehand, you can sometimes enter it during online check-in. Look for a traveler-information step in the check-in flow.

KTN vs PASSID: what’s the difference?

	KTN	PASSID
Issued by	TSA (PreCheck program)	CBP (Global Entry / NEXUS / SENTRI)
Where to find	TSA UEC dashboard, approval email	Back of your Global Entry card
Activates PreCheck?	Yes	Yes — Global Entry includes PreCheck
Activates Global Entry?	No	Yes
Format	9 digits	9 digits
Field to enter on airline booking	KTN field	KTN field (same field)

If you have both Global Entry and TSA PreCheck, use your PASSID — it’s the number that covers all benefits. Using your TSA KTN is also fine, but it’s simpler to maintain one number.

What to do if PreCheck isn’t printing on your boarding pass

If you’ve added your KTN to a reservation and still don’t see “TSA PRE✓” on your boarding pass, work through this checklist:

1. Name mismatch. The name on your reservation must exactly match the name on your TSA PreCheck enrollment. A middle name included in one but not the other, a suffix (Jr., III), or a nickname vs. full legal name can break the match. Check both.

2. KTN typo. Double-check every digit. Copy-pasting from the UEC dashboard (rather than typing by hand) reduces errors.

3. Membership expired. Log into the UEC dashboard and verify your membership is active. Expired members don’t get PreCheck. See TSA PreCheck renewal to fix this quickly.

4. Flight or airline not participating. Not every flight qualifies. Check the TSA participating airlines list. Regional feeder flights operated by express subsidiaries are sometimes excluded.

5. International-to-domestic connection. On some itineraries that begin internationally, the domestic leg may not carry PreCheck even if you’re technically eligible.

6. Reservation made as guest. If you booked without logging into your loyalty account, the KTN in your profile wasn’t pulled through. Add the KTN directly to the booking via “Manage Trip.”

If none of the above resolves it, call the TSA Contact Center at the number on tsa.gov before your trip. They can verify your record is active and correctly linked.

Common pitfalls

• Never saved the KTN anywhere. Your KTN doesn’t expire or change, but if you lose the approval email and forget your UEC login, recovering it takes a support call. Save it in your password manager or a note you’ll actually find.
• Adding KTN after check-in closes. Airlines typically lock the traveler-info fields once check-in closes. If you forget, you’re in the regular line that trip.
• Using the wrong 9-digit number. Confirmation numbers, redress numbers, and passport numbers are all about 9 digits. Make sure you’re using the right one from the UEC dashboard or your Global Entry card.
• Booking through a third-party travel site. OTA bookings (Expedia, Kayak, Google Flights) sometimes don’t display a KTN field. Book directly with the airline or add the KTN via the airline’s manage-trip tool after booking.

What to do next

If you don’t have a KTN yet, the first step is enrolling in TSA PreCheck. Once approved (typically 2–8 weeks), TSA sends your KTN by email. Drop it into your airline loyalty profiles immediately — you’ll never have to think about it again.

If you already have your KTN but the setup has been confusing, egovrush can help with the PreCheck enrollment and renewal process end to end. Get started with TSA PreCheck and we’ll guide you through it.

Frequently asked questions

What is a Known Traveler Number?

A Known Traveler Number (KTN) is a unique 9-digit code issued by TSA after your PreCheck application is approved. You add it to airline reservations so “TSA PRE✓” prints on your boarding pass and you can use the expedited security lane.

Where do I find my Known Traveler Number?

Log into the TSA Universal Enrollment Center dashboard at tsa.gov. Your KTN is displayed on your membership page. It was also included in your original PreCheck approval email.

Is a PASSID the same as a KTN?

They’re different numbers from different programs, but a PASSID works as a KTN. Global Entry members enter their PASSID in the KTN field on airline reservations to activate PreCheck — no separate PreCheck enrollment needed.

Why isn’t TSA PreCheck printing on my boarding pass?

The most common causes: KTN wasn’t saved to the reservation, the name on the booking doesn’t exactly match your enrollment name, your membership expired, or the specific flight or airline isn’t participating. Check each one in that order.

Can I use my KTN on someone else’s reservation?

No. Your KTN is tied to your identity and your TSA vetting. It won’t give PreCheck to someone else, and intentional misuse violates the terms of your enrollment.

Does every airline accept a KTN?

Most major U.S. carriers participate. You can check the full list at tsa.gov/precheck. Some international carriers on domestic routes may not be on the list.

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Sources: TSA PreCheck — Known Traveler Number, TSA participating airlines.