Tiny detail on your boarding pass could determine if you get a good plane seat

When you get a boarding pass there’s probably only one bit of information you really check - the flight number.

But have you ever wondered where those numbers come from? And do you know what all the other codes on your boarding pass mean?

In fact, there is one little code you may not have noticed before that can actually impact what seat you end up getting on the plane.

READ MORE: The $4 buy you should tuck into your suitcase every time you travel

Sequence number

It's a three-digit number that indicates the "sequence," or the order in which you checked in for your flight.

The code often begins with "SEQ" followed by a number, such as 016 – meaning you were the 16th passenger to check in for the trip.

READ MORE: 'Blown away': Where to stay in small island nation that should be on your radar

View gallery

One thing flight attendant would 'never ever' wear on a plane

"Sometimes, the order in which you check in can be significant. Certain airlines, often low-cost carriers, assign seats on a first-come, first-served basis," travel experts at Simply Flying revealed.

"Consequently, if you check in last, you are more likely to end up with a less desirable seat."

The sequence number is worth paying attention to as it keeps travellers abreast of check-in status, as well as potential perks and repayments that might become available due to flight delays and cancellations.

Here's a detailed rundown of the other secret information your boarding pass reveals. 

Passenger Name Reference (PNR)

This is one of the most important pieces of information on your ticket, because it’s the unique code which says everything about your flight.

It’s usually six letters long and indicates your name, ticket number, meal preference and any special requirements you may have. It’s also the code you’ll use to look your route up on tracking services, so it’s a good one to make note of.

That's why, even if you cover your name, someone who knows a little bit about boarding passes would just need your PNR to log in and change your flight booking.

Flight number

The letters at the start of your flight number indicate the airline, although these aren’t always easy to identify. Qantas is QF, Virgin Australian is VA and Jetstar is JQ – but airlines don’t always get the obvious code.

Southwest Airlines is WN for example – because SW, the code they wanted, was already taken.

The numbers after the code describe the route. As a general rule, the lower the number the more prestigious the route.

Qantas’ Sydney-London flight is QF1. Qantas also use odd numbers for outbound international flights, and even numbers to show inbound international flights.

READ MORE: NSW coastal town set to outshine most popular Aussie holiday spots

A higher number, such as a four-digit number starting with a 3, shows a codeshare flight – meaning it’s operated by a partner airline.

These numbers can be fairly freely assigned by the airline, so they’re free to skip the numbers they don’t want to use. You won’t find any 666 routes, or any 13, and flights to Asian countries sometimes try to get the number 8 in because it’s considered lucky in Asian culture.

Airlines are also free to change a number if a tragedy occurs. The infamous Malaysia Airlines MH370 flight is now MH360 and all the routes used in the September 11 hijackings have had their flight numbers changed.

But, without tragedy, some flights can have the same numbers for years. Delta’s flight numbers are still the same numbers used by Pan Am over 20 years ago.

Booking Class

Your boarding pass will also indicate somewhere on it the booking class. As a general rule, F is first class, J is business class and Y is economy – but many airlines have variations on these codes.

Some airlines also put a B in your class if you’re eligible for an upgrade, so keep an eye out for that. It will also be shown on your boarding pass if you booked a cheap flight, like a discount economy ticket, so don't expect to be able to snag preferential treatment on your cheapie ticket. 

Security Code 'SSSS'

If you’re travelling to the US and you notice SSSS printed on your ticket then you’re about to have a really long trip through security.

It stands for “Secondary Security Screening Selection” and basically means you’ve been marked for additional pat downs and swabs from security.

It’s a scheme which was brought in after the September 11 attacks, and there is a secret SSSS list somewhere – but it’s unknown how you get on it.

Some boarding passes are really in-depth and show your boarding priority, which door you’ll board through and whether you have a window or aisle seat.

If you can see you’re the last priority to board, at least you know you won't have to do a mad rush through the airport as soon as they open the gate. 

Stop doing this with your boarding pass

More importantly, did you know that some of that information can be used by scammers, as travel expert Eunice, from the Theory of Simple, warned.

"Stop doing this with your boarding pass or you're going to get in a lot of trouble," the seasoned traveller said.

In a video shared on Facebook, she called the sharing of an image of your ticket on social media a "big mistake".

"That little QR code or barcode on your boarding pass carries a lot of personal information," she said.

It could have things like your name, your email address, even your passport number and things like that on there.

"There are a lot of people out there who will take that information and do some things that could make life really rough for you," she added in the caption.

A note on paper boarding passes

Eunice also shared a warning for travellers that like to have a paper boarding pass.

"Make sure that you shred that before you just toss it in the garbage," she said, adding that if you like to scrapbook or keep them as souvenirs to "make sure you tuck it away somewhere safe."

Paper boarding passes might soon be a thing of the past though, with one major airline recently confirming they're set to scrap paper boarding passes by the end of the year.

Budget airline Ryanair revealed passengers will be required to have digital boarding passes issued through its app by November 2025.

View gallery

Secret words and codes flight attendants use and what they mean