Staying Three Beeps ahead of TSA PreCheck

TSA’s PreCheck service is great. In fact, I’m even willing to call it a “service” because it’s the one thing the TSA has actually gotten right as far as airport security is concerned. TSA officials claim that they want to make PreCheck the future for most passengers — not just elite passengers — and I sincerely hope that’s the case.

In the meantime, I am increasingly frustrated by its implementation at my home airport in Seattle. It was moved a few months back to a new location that is equally inconvenient from just about every gate and a longer walk from the transit link to downtown.

I now have to walk halfway down the airport, go through security, and then walk halfway back to reach my gate. It’s still worthwhile if I get the triple beep that says I’m cleared to use PreCheck, but if I don’t then the extra walking and waiting usually adds 10 minutes without much improvement in my security experience.

I want to know if I’m going to get approved for PreCheck before I walk out of my way to stand in that line.

Fortunately, that information is stored in your boarding pass barcode. It does not appear to be a random decision made at the time the boarding pass is scanned. If you can read that information, you should be able to find a common feature that identifies a PreCheck-approved boarding pass vs. a non-approved pass. (HT to Colpuck for being the first to share this as far as I know.)

I use an iPhone app called Qrafter (free download available from the iTunes App Store). This app was designed to scan QR codes, which advertisers often use to direct you to a web address. However, there are many forms of barcodes.

The barcode on your printed boarding pass is a standard 1D barcode since variations only occur in one dimension: the thickness of the bars. These won’t work with Qrafter. Mobile boarding passes come in a 2D form with changes along both the axes. QR codes have three squares in the corners to orient the scanner. Mobile boarding passes use a similar version called an Aztec code that uses a single square in the middle.

A boarding pass from a recent flight (the code has been corrupted).

A boarding pass from a recent flight (the code has been corrupted).

Determine Your PreCheck Status in Advance!

Here’s how I check my clearance to use the PreCheck lane before even showing up at the airport. (My example uses an iPhone.)

  1. Access your mobile boarding pass on your iPhone.
  2. Take screenshot by pressing the home button (at the bottom) and the power button (at the top) simultaneously. It helps if you press the one first and hold while you press the other button.
  3. Open Qrafter and tell it to scan a picture from your photo library. Be sure to select the option to move and scale since if the Aztec code is at the bottom it will get cut off.
  4. Access the screenshot and orient the scanner to center on the Aztec code.
  5. You’ll get a text output with lots of information, including your name, destination, confirmation number, and frequent flyer number. I’ve blurred some parts of the photos in this example to protect myself. 😉
  6. Look for a portion of the code, about four lines down in this example, right before the airline code (“UA” = United Airlines). There is a string of numbers that ends with either “2901….0 UA” or “2901…3 UA”
  7. If you get “0 UA” then you are not cleared for PreCheck. If you get “3 UA” then you ARE cleared for PreCheck.

Of course, TSA might be looking for something else, but I’ve had pretty good success using this method to predict whether I’ll get one beep or three. Remember, “3 UA” means 3 beeps and clear for PreCheck!

Sample output WITH PreCheck approval.

Sample output WITH PreCheck approval.

Sample output WITHOUT PreCheck approval.

Sample output WITHOUT PreCheck approval.

How to Improve your PreCheck Odds

Many people can get into PreCheck through an invitation from their airline loyalty program. That’s how Megan and I started (and she’s only Premier Gold with United). However, it doesn’t work that well as I explained in my introduction. At about a 50% success rate, it just created a lot of false hope.

But most people can go a step further and get a real trusted traveler ID that bumps your odds to almost perfect. The most obvious method is to get Global Entry, which costs $100 and may be reimbursed by your airline (United does this for Premier Platinum and Premier 1K members) or your credit card issuer (American Express does this for personal and business Platinum Card holders).

Less common are the NEXUS and SENTRI programs, intended for border crossings with Canada and Mexico, respectively. These two programs cost only $50, and you’ll still get a trusted traveler ID that can also be used for PreCheck.

Now I know I argued in the past with some who claimed you could use Global Entry kiosks with just a NEXUS card. I didn’t dispute that, only that I thought their use was still limited to kiosks at borders with Canada or Mexico. It just didn’t make sense that they’d give you all the same benefits as Global Entry for half the price, and the language online was a bit vague.

So I chatted up the friendly Customs and Border Patrol officer during my interview, and she confirmed this was true! She agreed it was silly but explained one catch: You can’t get NEXUS at just any CBP office; only those along the U.S.-Canada border (like in Seattle) are eligible. So you’ll need to come up here to get the sale price! Or, try for SENTRI if you live along the southern border with Mexico. In fact, NEXUS and SENTRI can potentially offer more benefits than Global Entry alone if you expect to do any land border crossings.

Once you have a trusted traveler ID, make sure it’s in your passenger profile when you book your ticket. When using the invitation-only process tied to an airline loyalty program, I was obviously out of luck if I booked with another airline besides United. But now I can use my number with any domestic airline. Finally, it’s also important to make sure your name on the reservation matches the one on your ID card, which means watching for things like middle initials.

If you don’t want to get a trusted traveler ID and want to rely on the free participation through your airline’s loyalty program, here are links to some of the major airlines’ information pages:

…And How to Game the System

I’ll end with a “trick” to at least expedite your security nightmare even if you don’t get to opt-out of the full body scan.

If you go through the PreCheck lane and get the dreaded single-beep, you will be shunted off to the normal security process, but you will also find yourself at the front of the line. Before PreCheck was moved at SeaTac, it actually ran parallel with the premium security line.

On occasions where there might be 20 people in the premium line, I knew I was PreCheck eligible, so I’d go in that line which had only one or two. Yes, my odds were only 50% in those days without Global Entry. But when I didn’t clear, I was not only at the front of the line but at the front of the premium line, too!

Airport personnel do check if you have a membership card or a first class boarding pass to enter the premium security lane. They do not check if you have Global Entry to enter the PreCheck lane, so anyone can go in knowing they will fail but still move to the front of the screening process.

I consider it dishonest to flash a grocery or other unrelated loyalty card and try to pass it off as though you’re a top-tier elite with access to the premium security lane. However, since no one is actually checking if you are eligible to use the PreCheck lane, this other approach seems somewhat permissible. I’ll leave you to make up your own mind, but I think it’s easier (and more reliable) to just pay $50-100 for a trusted traveler ID of your own.

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  • Helixcardinal

    Doesn’t work at SFO where they have the pre-check scanner at the end of the line, so you’re not all the way at the front when you’re checked.

  • Noah Kimmel

    Im slightly concerned that it is so easy to read it, and there are tons of QR code generators out there. It seems like it would be very easy to manipulate the QR to give you the three beeps, generate a fake BP, etc.

    • Scottrick

      I believe that was part of Colpuck’s original reason for posting this “hack,” to complain about lax security in the design. However, I caution anyone against generating their own boarding pass. That would violate federal laws and get you in a lot of hot water. The “3” may be easy to find, but there could be a checksum somewhere else in the boarding pass. If you just change a “0” to “3”, then the new boarding pass may deliver an error message.

      • Ben Hughes

        Right, it’s cryptographically secured with a checksum. So, although the values are readable, you would not be able to change the checksum to match your change and it would error out.

        • Javier

          Just curious, but how do you know there is a checksum that the TSA uses? I see some base64-encoded binary data at the end of my QR code, but that could be for the airline’s use and not TSA’s.

          • Scottrick

            I’m going to hope the government is moderately competent and would have thought to include that. Otherwise nothing really stops a person (including a terrorist) from making a fake boarding pass.

          • Upinzair

            It may be a matter of debate regarding the best way to get on the 3 beep “do fly list” but I can almost guarantee that tampering with a boarding pass will greatly increase your odds of landing on the “do not fly list.” You think taking your shoes off is a hassle? Try explaining to your co workers why you’ve been spirited off to the back room for a latex gloved exam and missed the flight.

  • NB

    The problem with Pre-Check is that it only covers domestic flights – which seems strange when it’s closely linked with Global Entry which is only relevant to international flights. As I generally only fly internationally, I haven’t bothered with it yet.

    • Scottrick

      Yes, I shared that frustration on my recent trip to BKK. Fortunately, most of my flights are domestic, but still often at odd hours when PreCheck is closed.

  • Tim Archer

    My home airport is small, so no pre-check. I often have to recheck in Dallas when returning from international trips, but have ALWAYS hit security at a time when Pre-Check was closed. Global Entry is wonderful; Pre-Check, not so much.

  • Jon

    If the simple appearance of a 3 allows you to get cleared for PreCheck, what would prevent someone from generating a new barcode with a 3 on it?? Certainly doesn’t sound very secure to me.

    • Jon

      I hope that there is some additional layer of validation – for example, when the barcode is scanned, I hope the scanner software compares what was scanned on the barcode with what is in the database to decide whether to allow someone through or not. Anyone dare to test the system? :)

  • Dad

    Minor correction from an old bar code expert: The code uses bars of varying widths AND SPACES of varying widths. I used to be able to read them without a scanner but I’m out of practice.

    • Scottrick

      That’s because you invented cuneiform before lasers! Everyone had to read without a scanner.

  • HoKo

    Very useful info!

  • TravelBloggerBuzz

    Good stuff here, thanks.

  • Kris Ziel

    As far as United goes, PreCheck isn’t invitation only, a simple google search for united precheck will take you to the page where you can opt in, although I’m not sure how likely you are to get precheck at the airport.

    • AKold

      It’s the same as Delta, though the “success rate” is higher if you are actually part of Trusted Traveler.

  • Colin R. Ley

    Thanks! I have been trying to figure out how to improve my 3-beep success rate. I have noticed that I always get 1 beep when I make any changes leading up to or during my trip. For example a seat change before the flight or when I fly out on a paper boarding pass (3 beep), but return on a mobile boarding pass (1 beep).

    • BlueWindez

      Scottrick – You really need to investigate this. Every time US Airways changes my seat, I lose pre-check. And since I’m silver flying a low-use route, I would guess I’m losing pre-check 60-75% of the time. It’s a major flaw in the system. I can’t get to the airport knowing I’ll get through (DCA can get hour long clogs for incompetence). Would love to hear others’ feedback on this point.

      • Scottrick

        That’s interesting. Where is your trusted traveler number stored? I know that United and Alaska store it in the passenger profile, separate from the reservation (but you can add it there, as well). If you are only adding it to each reservation but not to your general profile, then maybe it’s getting lost when the reservation details are updated.

        • BlueWindez

          I have it stored in my US Airways account. So I don’t usually have to enter it again (though today I did, for some reason). I talked to a US Airways mgmt supervisor this morning, and he said he’d look into it. Recognized that it happens. The TSA guys were the ones who alerted me to it (several different times in diff airports, so the tip seems legit).

  • mrssjr

    Any similar Apps that will work with Androids?

    • Scottrick

      I would guess most QR code readers would work. Here’s one for Android:

      • mrssjr

        FYI – this particular one does not work with Aztec. I found NeoReader that does…and I’m PreCheck approved for tomorrow’s flight:)!

        • Scottrick

          Thanks! I have no Android experience.

        • Sam

          How did you get yours to work with NeoReader? It tells me that file type is not supported.

          • mrssjr

            I sent the boarding pass to my tablet, opened it up and scanned with NeoReader. I wasn’t able to do it only on my phone. Still looking for one that works straight off the android though.

  • Ethan Jones

    This is why your blog is my favorite. Great stuff, Scott!

  • Eric Johnson

    So, my story is…I signed up for the Global Entry program (in San Diego no less – I could have saved $50 :) and although I’ve only taken a few flights since being part of the program, I have yet to be granted 3 beeps.

    Is it possible that since I book my flights on a company travel website, I am somehow being excluded?

    • Sean

      Make sure your Global Entry ID is included in your identifying information. Because you booked on a company travel website, it’s likely you need to enter your ID separately on the airline’s website using your confirmation number.

    • emcampbe

      Also, make sure the name you use in the Secure Flight information from your airline (now, I think, pretty much the same as on your ticket) matches exactly with the name you have with GE. For example, if your GE includes your full middle name, but the name the airline sends for secure flight doesn’t, or includes just your middle initial, that’s enough to mismatch, which is almost guaranteed to make pre-check fail every time.

    • Sunnydayz

      Verify you are entering the correct number (see global or for help) and verify that it is in the Known Traveler Number field of all reservations. if it’s not in the reservation or if it is in the wrong format (i.e. Redress Number), you won’t be selected. Also, verify the details in your Change Profile screen match what you or your travel agent have entered into the Secure Flight Passenger Data of all reservations. A typo can prevent you from being selected.

  • Neet

    Scott, I got the Global Entry a few years back and am a Delta Platinum and have the trusted traveler number in my profile added, yet I have never ‘ever’ been “selected” for the Pre-Check and I don’t understand why. I have talked to the TSA folks and they say it’s “random” and even called Delta platinum line and they say it has nothing to do with them. I have checked my traveler number, my name on my ids and everything checks out fine, yet for some mysterious reason, never once been given the “3 beeps”. The only benefit I get out of it is using the kiosk on my return back to US from international travels. That’s it. I’d absolutely love some guidance or ideas on what I can do. Help me folks. :)

    • Scottrick

      You got me. Are you doing any domestic flying? PreCheck doesn’t work when you’re on an international itinerary.

      • joschmo

        You probably need to enter your trusted traveler # on the Delta site. It’s fairly hidden, under profile, then hit edit your secure id profile. I just did it, and now I’m presuming it will be loaded for pre-check.

    • Brian Kusler

      i’ve seen two things trip people up: one friend was entering the number from the right-hand side of their GE card instead of the PASSID number from the left, and another had his FF profile set up with a middle name that didn’t exactly match his ID. in both cases when that was fixed, the 3 beeps started flowing.

    • Jon H.

      I have Global Entry and am American Platinum. At first getting through Precheck was iffy but the last couple trips, I noticed at MIA and SFO, there is a separate line for Precheck. Before, it was necessary to get the initial ID and boarding pass check and the TSA person would direct you to either the regular First Class/Priority Access line or the Precheck line. Another item of interest to me is I have never heard of the “beeps” before.

    • sunnydayz

      Are you a US or Canadian citizen? Are your itineraries entirely for trips within the US? Does all of your Secure Flight Passenger Data in your reservations match the Change Profile screen? The data in your reservation is matched against CBP’s data for GE/Nexus/Sentri users. If the data doesn’t match, you won’t be selected.

    • Mario L

      It could be what happened to me. I am an American Platinum with Global Entry and never worked before. I went to TSA to American checked everything and nothing. Then I saw that both my name and middle names were on the first name field on the Global Entry ID, so I called AAdvantage and asked them to add my middle name to the first name field and that actually worked.

  • emcampbe

    Two things.

    One…Using the pre-check line to get to the front only works in some places. In my home airport at CVG, for example, if you only get the 1 beep, you get sent to the back of the regular line.

    As for Nexus/Sentri folks getting access to GE, yes, this is correct…any Nexus member (who has all of their fingerprints on file) has access. Some members don’t (not intially required, but is now), but they can get it by stopping by a Nexus or GE office to have it done. The thing is, anyone who is approved for Nexus had the same background check completed by the US that is used for GE, so is silly not to allow travelers who are already approved to use GE. Nexus just happened to be available first. I’m actually surprised prices of Nexus haven’t gone up after GE was introduced at double the price…I expect it will at some point. Honestly, it’s the best $50 I’ve ever spent…that’s $10/year for access to the program.

    As for having to go to a Nexus office in Canada or near the Canadian border for Nexus, yes this is true also, and makes complete sense. To get Nexus, you have your background/criminal record check in both the US and Canada, and need to interview with both US and Canadian officials. Since Canadian customs doesn’t have officers in GE offices (or in the US…save for a few Nexus offices at border locations or in cities near the border, like Seattle), you need to go to an office where they are present to do the interviews.

  • Scott

    Sort of surprised you find it “dishonest” to flash a fake card to enter the Elite lanes, but no problem with people pretending/lying about being Pre eligible to bypass the “Elite” line.

    “They do not check if you have Global Entry to enter the PreCheck lane, so anyone can go in knowing they will fail but still move to the front of the screening process.”

    At least end it with, those that are already aware, by using this method to see if they get 3 beeps or 1 can still go into the Pre Lane.

    Truth is the TSA should have a checker prior to entering that Pre Lane and if you fail you go to the end of the Elite lanes or the regular lanes.

    • Scottrick

      If I show a supermarket loyalty card and try to pass it off as an airline loyalty card, that’s providing false information, an act of commission. If I just walk into a line where they don’t screen at the entrance, then I’m not telling anyone anything, an act of omission, which some view as less severe.

      I’ve given up telling the TSA what they should do. If they actually cared about security, things would be different.

  • Debbie B

    IS there a trick to get the $100 reimbursed from AMEX? I called and they said NO SUCH THING?? Thanks!

    • TR

      It’s actually is no trick to getting the $100 reimbursed from AMEX. You need to be an AMEX Platinum card holder or higher to get the reimbursement.

  • Debbie B

    Oh I have Costco’s AMEX card. Maybe that’s why. Hey if you are in the Travel Business this may be a good 1 – stop portal for you. You can get cashback on your travel. I just used it for our trip this wknd. It’s not much for air but it can add up because your group will be growing! Even for FREE members. And cashback for shopping online using your own credit card. Some credit cards already offer a percentage cashback! For Home Depot, we order online and pickup at store.

    They do not ‘USE’ your information…it is kept private
    and they give the money back to YOU instead of using YOU to make THEM money like


  • Myron Marvin

    “You can’t get NEXUS at just any CBP office; only those along the U.S.-Canada border” You can get your first NEXUS interview at SFO (San Francisco Airport) but no matter where you are interviewed in USA, you also need to be interviewed in Canada.

  • Sam

    An easier way to use your iPhone to scan the bar code on your boarding pass is to use the “Boarding Pass Scanner” app. It’s $.99 but it does the work of decoding the cryptic string for you.

  • Airracer

    My wife was in Pre-check in Austin and I was in the regular line. I actually finished ahead of her! When I go through the line, my pockets are empty, no belt, everything on me is in my backpack which goes through the scanner and I don’t have to fumble and shuffle around like most donkeys do when they get there. All I have to do is walk up, put my pack on the belt and walk through.
    Think people!

    • FlatusOhlfart

      you’re a good sheep.

  • Hipster

    The barcode format is pubic knowledge. IATA Resolution Standard 792. You didn’t crack any code or do anything special.

    • Scottrick

      I showed people who didn’t know what to look for how to translate it into text and what part they should examine. Correct me if I’m wrong, but that’s not common knowledge.

  • Hipster

    The barcode data format is pubic knowledge. IATA Resolution Standard 792. You didn’t crack any code or do anything special.