The standard behind it
Airline boarding passes use a data layout set by IATA Resolution 792, the Bar Coded Boarding Pass standard. It lets any airline or airport scanner read any carrier’s pass, including for connecting flights.
IATA members moved from magnetic-stripe passes to barcoded boarding passes over the 2000s, and the industry reached full BCBP adoption around 2010.
Which barcode types are used
Printed boarding passes use PDF417, a stacked linear barcode. Mobile boarding passes shown on a phone screen can use Aztec, QR or Data Matrix, with Aztec especially common in airline apps and phone wallets.
The data inside is the same fixed-format text whichever symbology is used, so the barcode type mostly reflects what the scanners and the medium handle best.
What the barcode contains
The data is mostly plain, unencrypted text in fixed-width fields, and any barcode reader can decode it. The mandatory part covers each flight leg, and optional fields can add items such as frequent flyer numbers, followed by an optional security signature.
- Passenger name (surname and given name)
- Booking reference (PNR code)
- Origin and destination airport codes
- Airline and flight number
- Date of flight, as the day of the year
- Cabin, seat and check-in sequence number
Why not to post a boarding pass photo
A photo of a boarding pass, including just the barcode, can reveal the passenger’s name and booking reference. With those two items, someone can often log in to the booking on the airline’s website, see personal details, and in some cases change or cancel the trip.
It is safer to keep boarding passes private and to shred printed ones after travel rather than throwing them away whole.