Whether you’re a fan of the digital version or prefer the old-school paper printout, a boarding pass is a necessary document for air travel. Not only does it allow entry onto your flight, it also serves as an identity document and security pass, and holds some key information about your trip and passenger details—right down to whether you’ve requested a special meal for your flight.
Some of the letters and numbers on the document are fairly self-explanatory (flight number, boarding group, and an airline’s abbreviation, for example), but the rest can seem like a jumble of alpha-numeric randomness. There’s a method to the madness, however. Here, we dig in to help you decipher what it all means.
Bar code
One of the most recognizable items on your boarding pass is the bar code. The magnetic strip, called BCBP, or bar-coded boarding pass, often appears on the bottom right side of your pass, but there’s no hard and fast rule about its placement. The bar code must meet the standards of the International Air Transport Association (IATA), an airline trade group that sets criteria for consistency across the airlines and countries. The bar code is often scanned at the gate and helps speed up the boarding process. The scanner also records the information, so gate agents and the crew on the plane can easily tell how many passengers have boarded, what seats are taken, and how many bags have been checked.
Your unique identifier
The six-digit alphanumeric code that appears on your boarding pass is your PNR, or Passenger Name Reference—also known as your record locator, reservation code, or booking code.
This randomly generated sequence is what you need to type into a computer or a self-serve kiosk at the airport to retrieve your boarding pass, and is what identifies you as a unique passenger—you know, just in case there’s someone else with your exact first and last name on your flight. Among other things, this PNR holds information about your meal preferences or other special requests. It’s also one of the main reasons you shouldn’t throw away your boarding pass in a public trash can, as someone may be able to pull your information using your reservation number or bar code.
Flight code and number
There’s generally a simple formula for this one: two uppercase letters, followed by a four-digit number. The letters are the airline code, or the numbers universally recognized to represent the name of the airline in shorthand. Some are obvious—AA is American Airlines, for example. But plenty more are not, especially for carriers based outside of the United States (and some domestic airlines as well: JetBlue, for instance, is B6). IATA maintains a list of all its member airlines, including the airline code for each.
The flight number is determined by the airline, using a complex algorithm that takes into account past and current airline flight numbers, as well as factors like other airlines with similar sounding numbers scheduled to fly through the same airspace at the same time. This helps avoid potential confusion with pilots and air traffic control.
A floating letter
You may notice a letter on your boarding pass that’s distinct from all the others—a lonely “B” hanging out by itself, for instance. That letter may be the most classist part of your ticket (aside from your seat assignment). The stray letter may appear next to your seat assignment, flight number, or even just adjacent to the date and time of your flight. Different letters mean different things to different airlines, but generally, the letter marks your airline status, aka, your likelihood of getting an upgrade based on your loyalty status and which seat you booked. An “A” or “F” mean first-class treatment, while a “B” often means you’re more likely to get upgraded than if you have a “Q” or a “Y” on your ticket—the latter two are typically the cheapest economy fares.
Other airlines
Note the line on your boarding pass that says “operated by,” which tells you what you may have missed during the booking process: that your flight is not actually being flown by the airline you thought you were traveling with. Often, airlines sell tickets on their sites for flights operated by partner airlines, sometimes known as codeshare flights, or subsidiary ones on regional jets that they own but don’t operate. American Eagle is one example, as it’s owned by American Airlines but operated by a different company with distinct rules and structuring.
Security codes
There’s no way to know with certainty whether you’re going to be frisked by security at the airport. But that’s a likely scenario if there’s an “SSSS” on the bottom of your boarding pass. The code, which is the Transportation Security Administration’s way of flagging passengers, stands for “Secondary Security Screening Selection” and means you’ve been pre-selected for additional security screening.
While the criteria for how one ends up on the list isn’t clear, it includes people who appear on the No Fly List and the Do Not Board List put out by the U.S. government’s Terrorist Screening Center and the Centers for Disease Control and Prevention, respectively. In addition, passengers can be flagged for flying from, to, or through countries deemed “high-risk” by the State Department, or if their name bears even a passing resemblance to someone on a Department of Homeland Security watch list.
In addition, behavior that’s inconsistent with your previous purchasing patterns (paying cash for a flight, for example), buying a ticket less than two weeks out, and buying a series of one-way tickets (a common practice among mileage runners and points devotees) can also lead to the SSSS appearing on your boarding pass.
Stopover
You’ll see an S/O on your boarding pass if you have a stopover or layover, and “SPTC” if you have a stopover that lasts longer than a few hours, in which case the airline may even put you up in a hotel. Though many stopover programs are still on pause amid the pandemic, some are up and running again—including Turkish Airlines' Istanbul stopover, which comes with a free stay in a four-star hotel.
This story has been updated since its original publish date.