What Is a Known Traveler Number, and What Do You Do With One?

A Known Traveler Number (KTN), also called a Trusted Traveler Number, is a number issued by the US Transportation Security Administration (TSA), Department of Homeland Security (DHS), or Department of Defense (DoD). This number indicates that you have undergone a pre-flight background check or other screening before checking in for a flight.

Adding your Known Traveler Number to an airline reservation greatly increases your chances of being able to use the TSA's PreCheck security screening lanes at participating US airports. Your KTN also permits you to take advantage of expedited customs processing at select airports if you are a Global Entry member.

How Can I Get a Known Traveler Number?

The easiest way to get a KTN is to enroll in either the PreCheck or Global Entry program. If your application is approved, you will receive a KTN. A Global Entry KTN is linked to your passport information, while a PreCheck KTN is connected only to the personal information you supplied when you enrolled. Participating airlines may offer their frequent flyers PreCheck status. The airline will assign these travelers a KTN as part of that process. Active duty military personnel may use their DoD identification number as their KTN.

You may also apply for PreCheck or Global Entry on your own. US citizens pay $85 for a five-year PreCheck membership or $100 for a five-year Global Entry membership. (Tip: The nonrefundable fee must be paid whether or not you are approved for PreCheck or Global Entry.) If your travels frequently take you outside the US, Global Entry might be a better option for you because it not only provides you with a KTN but also gives you access to faster customs processing access at certain airports.

How Do I Use My Known Traveler Number?

If you received your KTN through the TSA's PreCheck program, you should add it to your reservation record every time you book a flight on a participating airline. If you make a flight reservation through a travel agent, give the agent your KTN. You can also add the KTN yourself if you reserve your flight online or by telephone. 

Participating airlines, as of this writing, include:

• Aeromexico
• Air Canada
• Air France
• Air India
• Air Serbia
• Alaska Airlines
• Alitalia
• All Nippon Airways
• Allegiant Air
• American Airlines
• Aruba Airlines
• Asiana Airlines
• Austrian Airlines
• Avianca
• Azul Airlines
• Boutique Airlines
• British Airways
• Brussels Airlines
• Cape Air
• Cathay Pacific Airways
• China Airlines
• Condor Airlines
• Contour Aviation
• Copa Airlines
• Delta Air Lines
• Eastern Airlines
• Edelweiss Air
• Elite Airways
• Emirates
• Etihad Airways
• EVA Air
• Finnair
• Flycana
• Frontier Airlines
• Hawaiian Airlines
• Icelandair
• InterCaribbean Airways
• Interjet
• Japan Airlines
• JetBlue Airways
• Key Lime Air
• KLM Royal Dutch Airlines
• Korean Air
• Lufthansa
• Miami Air International
• Norwegian Air
• PAL Express
• Philippine Airlines
• Porter Airlines
• Qantas
• Qatar Airways
• Scandinavian Airlines
• Seaborne Airlines
• Silver Airways
• Singapore Airlines
• Southern Airways Express
• Southwest Airlines
• Spirit Airlines
• Sun Country Airlines
• Sunclass
• Sunwing Airlines
• Swift Air
• Swiss International Air Lines
• Swoop
• TAP Air Portugal
• Turkish Airlines
• United Airlines
• Virgin Atlantic
• VivaAerobus
• Volaris
• WestJet
• World Atlantic
• Xtra Airways

If you obtained your KTN through the Global Entry program or by virtue of your status as a US Armed Forces member, you should use it whenever you make an airline reservation, regardless of which airline you fly.

Why Don't I Get PreCheck Status Every Time?

There are several reasons why you might not be able to use the PreCheck screening lane, even though you have a KTN. For example:

Sometimes the TSA does not give PreCheck status to enrolled travelers as part of its effort to randomize security screening procedures.

The data you entered when you bought your ticket might not match the data on file with the TSA, DHS, or DoD. Your first name, middle name, last name, and date of birth must match exactly.

You may have entered your KTN incorrectly when you bought your ticket.

Your KTN might not be saved in your frequent flyer profile, or you may not have logged in to your frequent flyer account before you bought your ticket online.

If you bought your ticket through a travel agent or third party website, such as Expedia, your KTN might not have been passed along to your airline. The best way to correct this problem is to call your airline and make sure your KTN has been entered into your reservation record. Do this before you check-in for your flight.

You may not have noticed that you could not enter your KTN when you purchased your ticket online. This occasionally happens with online travel websites (third party websites). 

How to Resolve Problems

Once you have a KTN, you are supposed to use it. Always look for the KTN field when you buy an airline ticket online. Contact your airline after you complete your purchase if you do not see it.

Double-check your travel documents (driver's license, government-issued photo ID and/or passport) to be sure your full name and birth date match the information you provided to the TSA or DHS. Save your KTN in your frequent flyer account record(s). Check your frequent flyer account profiles regularly to make sure your KTN is still entered correctly. Train yourself to look for the KTN field and enter your KTN whenever you buy an airline ticket. Call your airline before your check-in date to be sure your KTN has been added to your reservation record.

When you print your airline ticket, you should see the letters "TSA PRE" in the top left corner. These letters indicate that you have been selected for PreCheck status on your flight. If you are enrolled in PreCheck but do not see "TSA PRE" on your ticket, call your airline. The reservations agent will be able to help you sort out any problems. Remember that the TSA will not always select you for PreCheck status, even if you are enrolled in the PreCheck program.

If you encounter problems at check-in or at the airport, contact the TSA as soon as possible to find out what happened. According to the Wall Street Journal, the TSA only retains PreCheck data for three days after your flight, so you will need to act quickly.