This post contains references to products from one or more of our advertisers. We may receive compensation when you click on links to those products. The content on this page is accurate as of the posting date; however, some of the offers mentioned may have expired. For more information check out our Advertising Disclosure. Having TSA PreCheck is a huge time-saver at the airport, getting you in a faster security lane where you can keep your liquids and electronics in your bag and your shoes on. But nothing can sour the start of your trip more than getting to the security checkpoint only to discover TSA PreCheck doesn't show up on your boarding pass.

In order to get into the TSA PreCheck lane, your ticket must display the TSA PreCheck logo, even if you can prove you're signed up. Without it on your boarding pass, you'll have to go through the general security screening process with the throngs of other travelers.

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It's annoying to be sure, but it happens to the best of us. There are a number of reasons why TSA PreCheck might not be showing up on your boarding pass, and in many cases, they're easily remedied.

Read on to find out why TSA PreCheck isn't showing up on your boarding pass and what you can do to make sure that it does.

Reasons TSA PreCheck Isn't Showing Up on Your Boarding Pass There are several reasons why TSA PreCheck won't show up on your boarding pass. Sometimes, you simply don't have the option to add it. Other times, it's something that's easily remedied so long as you realize it before you get to the airport.

Understanding some of the common reasons TSA PreCheck isn't showing up on your boarding pass may help you prevent it from happening in the first place and save you some stress when you arrive at the airport.

The Name on Your Booking Doesn't Match Nine times out of ten, it's all about your name.

Don't get us wrong, you have a beautiful name. But the issue is usually that the name you input on your flight booking does not match the name registered to your Known Traveler Number (KTN) the key to using PreCheck.

The quickest way to resolve this issue is to contact your airline via chat or on social media (Twitter and Facebook). If all fails, you should contact TSA directly through Apple iMessage by texting Travel to 275-872, calling (866) 289-9673 or messaging @AskTSA on social media.

You Didn't Add Your Known Traveler Number to Your Booking We all make mistakes. Once you've signed up for PreCheck and you've got your KTN, you have to make sure you enter this number in the correct box when booking your flights.

Better yet, we recommend adding your KTN to each of your frequent flyer accounts that way, it should be automatically included whenever you book a flight. It's better to do it early on in the process rather than waiting to input your KTN during online check-in.

For example, here's what to look for if you're trying to add your KTN to your American Airlines AAdvantage account.

Do not put it into the Redress number field, even if that's the only option available.

If, while checking in online for your flight, you discover that TSA PreCheck somehow didn't show up on your ticket or your KTN did not populate automatically to your reservation, you should have the option to add it at this stage. Simply edit your traveler information on the web or mobile app.

Your TSA PreCheck is Expired There's a good chance you forgot or were unaware of your TSA PreCheck expiration date.

You'll need to renew your PreCheck every five years to keep it active. Luckily, the TSA PreCheck renewal process is much easier than the enrollment and cheaper, too.

Unlike the initial application that requires a background check, the vast majority of current TSA PreCheck members can simply renew their memberships online. The renewal window opens six months before the current expiration date.

A few years ago, the TSA made a consumer-friendly move by lowering the cost of renewing PreCheck to $70 for another five-year stint when renewing online. In-person renewals which are mandatory when a traveler has a name change, for example will still cost $78 for another five years.

When you're ready to renew, simply head to the TSA PreCheck renewal page and fill out the form. Of course, if you access TSA PreCheck through Global Entry you'll need to go through the Global Entry renewal process instead.

Your Airline Isn't Part of TSA PreCheck Once upon a time, I was flying with ZIPAIR from Honolulu (HNL) to Tokyo (NRT) when I encountered a stressful situation: After several delays and cancellations, I finally made it to my hotel and went to check in for my flight onward to Japan.

My day got worse: There was no place to put in my KTN to get PreCheck.

Having taken for granted how easy it is to get PreCheck when flying with most U.S. airlines, I realized that not all international carriers participate in the program. Of course, now, ZIPAIR participates in TSA PreCheck. With more than 100 airlines and counting now on the TSA PreCheck list, most U.S. and major international carriers offer PreCheck but there are still a few exceptions notably, European budget carrierPLAY Airlines, EgyptAir, and major Chinese airlines China Eastern and China Southern.

Do some prior research on whether your airline participates in TSA PreCheck so you won't be flustered when you get to security and have to wait in the general security line. Messaging the airline the day before will not help if they simply offer no option for you to input your KTN. And again, under no circumstances should you put your KTN in the Redress number box.

How To Add TSA PreCheck to Your Boarding Pass When booking a flight, you will have the option to input your TSA PreCheck number along with your other passenger information. Your Known Traveler Number (KTN) is what you need to enter here.

However, it's best to add your KTN to your frequent flyer account so you have a faster time checking out when booking a flight. Your TSA PreCheck number will be automatically associated with your booking if you are logged into your airline account at the time of booking. You can add your KTN under your profile settings.

You should also have the option to add your KTN to your booking while checking in for your flight online or on the mobile app. Remember: Do not put your KTN into the Redress field.

If TSA still isn't showing up on your boarding pass, contact contact your airline via chat or on social media (Twitter and Facebook). If all else fails, you should contact TSA directly through Apple iMessage by texting Travel to 275-872, calling (866) 289-9673, or messaging @AskTSA on social media.

Before heading to the airport, double-check that the TSA PreCheck logo appears on your final mobile or paper boarding pass. You'll have fewer options to resolve the issue if you try to do so at the airport.

What To Do If You Can't Add TSA PreCheck? Sometimes, your airline and TSA customer support simply can't help you.

Earlier this year, I was traveling with my dad and his TSA PreCheck was not showing up on his boarding pass. Despite hours of communicating with my airline and TSA customer support, the issue could not be resolved before my flight.

In these situations, it's better to keep calm and consider your alternatives as far in advance as possible.

Read on to learn a few alternatives to have in your back pocket prior to checking into your flight to be prepared if TSA PreCheck is not showing up on your boarding pass.

Sign Up For CLEAR CLEAR® Plus is a privately run trusted-traveler program that uses both fingerprint and iris identification technology to confirm a traveler's identity.After enrolling on their website, travelers can go to any airport offering the service to complete the registration process, which takes around five minutes.

Once you have been cleared at the CLEAR personal kiosk, ambassadors escort you to the front of airport security lines to have your boarding pass checked by a TSA agent.

But that brings us to an important point about CLEAR® Plus: It's much different from TSA PreCheck. CLEAR® Plus simply allows you to jump to the front of the general screening security line. You still have to remove your jacket, shoes, liquids, and electronics like everyone else. TSA PreCheck is a completely different security line.

It's a good alternative to save time going through security, but do understand this: it's not a replacement for TSA PreCheck.Having both could be a powerful combination, though, as you'll jump to the front of the PreCheck line rather than the general security line after being cleared at the CLEAR kiosk.

But not always. With more and more travelers signing up for CLEAR® and a limited number of agents available to keep travelers moving, CLEAR® queues can get long at many busy airports.

Unlike TSA PreCheck, airlines don't have to opt into participating in CLEAR® Plus. Whether or not you'll be able to use CLEAR depends on the airport. Currently, CLEAR is available at over 50 airports across the U.S. and counting.

But CLEAR® Plus comes with a hefty price tag of $189 a year. While you could get it for cheaper through an airline frequent flyer account or by holding credit cards with a CLEAR credit, the price is still quite expensive compared to the $78 (or less) you pay for five years of TSA PreCheck.

Whether or not it's worth the cost, especially given you might still have to show your ID to the TSA agent, is up to you. But it's an option if you can't get TSA PreCheck to show up on your boarding pass and are worried about getting bogged down at security.

Read our full guide to how CLEAR works!

Reserve Your Spot in the Security Line For Free! Don't feel like paying for TSA PreCheck or CLEAR? Select airports across the country, including some in Canada and Europe, allow U.S. travelers to reserve their space in line to go through TSA security screening at a specific time. The best part? It's 100% free.

Your window to make a reservation is between seven days and 60 minutes before your scheduled flight boarding time. You simply arrive at the airport with the QR code you receive after making a reservation and enter a special lane that takes you and your traveling party (up to 10 passengers total) to the front of the general security line.

Today, it's available at nine U.S. airports though not at every terminal. It's also available at a handful of Canadian airports as well as a few in Europe.

Denver (DEN) Houston-Intercontinental (IAH) Los Angeles (LAX) Minneapolis-St. Paul (MSP) New York City (JFK) Newark (EWR) Orlando (MCO) Phoenix (PHX) Seattle (SEA) More airports across the country are expected to adopt a similar program in the near future.

Read more on the free airport security reservation system

Bottom Line TSA PreCheck not showing up on your boarding pass is a common problem heck, it's happened to many of us on the Thrifty Traveler team. And there could be a number of factors at play causing that issue.

Understanding the most common problems can help you prevent it from happening in the first place, helping you speed through TSA PreCheck as planned.