The short answer: a printed boarding pass carries a PDF417 barcode holding the IATA BCBP (Bar-Coded Boarding Pass) data. A mobile boarding pass shown on your phone uses a 2D matrix code instead — most commonly Aztec, sometimes QR or Data Matrix — because a square code fits a screen better than a wide strip.
The IATA BCBP standard
Aviation cannot have every airline using a different code — a passenger connecting between carriers has to scan at any gate, any airport. So IATA (the International Air Transport Association) defined the Bar-Coded Boarding Pass standard, which fixes both the data layout and the symbologies allowed. Every compliant pass encodes the same fields in the same order, so any BCBP-aware reader worldwide can decode it.
Printed PDF417 vs mobile matrix codes
BCBP comes in two physical flavours:
- Printed pass → PDF417
- A wide, stacked 2D barcode. Its elongated shape sits naturally on the tear-off strip, and airport laser-and-imager hardware has supported it for decades. This is the classic "boarding pass barcode".
- Mobile pass → Aztec / QR / Data Matrix
- On a phone, a square matrix code is easier to display and scan than a long strip, so mobile BCBP allows Aztec, Data Matrix or QR. Aztec is especially common because it needs no surrounding margin.
If you want the deeper comparison of these symbologies, see QR vs PDF417 vs Aztec vs Data Matrix.
What the barcode contains
The BCBP payload is a compact string of fields, not a secret. Decoding one reveals roughly:
- Passenger name
- Booking reference / PNR (the six-character record locator)
- Flight number and operating carrier
- Origin and destination airport codes
- Date of flight and Julian date
- Seat number and boarding sequence number
- Cabin / fare class and, where present, a security signature
Notably, it does not contain payment details or a password — but it does contain enough to look up your booking, which is the basis of the privacy note below.
How to read a boarding pass barcode
Scan the code with any barcode app that supports PDF417 and Aztec, and you get a line of fixed-width text like this (a made-up sample):
M1SAMPLE/ALEX EXYZ789 LHRJFKXX 0123 275Y014C0042 100| Characters | Example | Meaning |
|---|---|---|
| 1–2 | M1 | Format code and number of flights in the barcode |
| 3–22 | SAMPLE/ALEX | Passenger name, surname first, padded to 20 characters |
| 23 | E | Electronic ticket |
| 24–30 | XYZ789 | Booking reference (PNR) |
| 31–36 | LHRJFK | From and to airports |
| 37–44 | XX 0123 | Airline and flight number |
| 45–47 | 275 | Date as day of the year (275 = 2 October in a non-leap year) |
| 48 | Y | Compartment / booking class |
| 49–52 | 014C | Seat 14C |
| 53–57 | 0042 | Check-in sequence number (also printed as "SEQ") |
| 58 | 1 | Passenger status (1 = checked in) |
| 59–60 | 00 | Length of the optional data that follows, in hex |
Optional data after that can include the BCBP version, document type, frequent-flyer number, baggage tag numbers and airline-private fields, followed by a ^ and the security signature. Try it on your own pass with our free boarding pass decoder — it runs in your browser and uploads nothing.
Round-trip, connecting and infant passes
- Connecting flights: a single barcode can hold up to four flights (
M2,M3,M4), but most airlines still issue one pass per flight. - Return flights: you normally get the return boarding pass only when check-in for that flight opens, so a "round-trip boarding pass" is usually two separate passes.
- Infants on lap: lap infants often get their own boarding pass or have an infant indicator on the adult's pass. If an infant pass has no barcode, ask at check-in or the gate — it's usually checked against the adult's booking.
- Mobile vs printed: the same data is in both; only the barcode symbol differs.
Signatures and security
BCBP supports a digital signature over the data. When present, a gate reader can verify the pass is genuine and unaltered without contacting a server — useful at remote gates and during outages. As with every ticket, though, the real protection is the airline's departure-control system marking each boarding pass as used, so the same sequence number cannot board twice. The barcode is the lookup key; the system enforces the rules. (See ticket security.)
Getting it to scan
- Mobile: brightness to maximum, auto-brightness off, code shown whole with a little margin. Add the pass to your phone's wallet so it works offline and surfaces quickly.
- Printed: plain paper, black on white, do not fold across the PDF417. A creased or faded thermal print is the usual reason a printed pass fails.
If it reads but is declined, the issue is in the airline's system — see why won't my ticket scan.
A privacy note on photos of boarding passes
Because the barcode encodes your name and booking reference in the clear, posting a photo of your boarding pass online can expose your booking. Anyone who decodes the code may be able to access your reservation on the airline's site. Don't share images of boarding passes, and bin printed ones rather than leaving them on the seat.
Frequently asked questions
What barcode is used on airline tickets?
Printed boarding passes use PDF417, a stacked 2D barcode, carrying the IATA Bar-Coded Boarding Pass (BCBP) data. Mobile boarding passes use a 2D matrix code instead — most often Aztec, sometimes QR or Data Matrix — because those fit better on a phone screen.
What does the boarding pass barcode contain?
It encodes the BCBP fields: passenger name, booking reference (PNR), flight number, origin and destination airports, date, seat, sequence number and cabin. Higher-security passes also include a digital signature so the code can be checked offline.
How do I read the barcode on my boarding pass?
Scan it with a barcode app that reads PDF417 or Aztec. The text starts with M1 (one flight) and is fixed-width: 20 characters of name, then e-ticket flag, booking reference, from and to airports, carrier, flight number, day of the year, class, seat, check-in sequence and status. Paste it into a BCBP decoder to see each field labelled.
What does BCBP mean?
Bar-Coded Boarding Pass — the IATA standard (Resolution 792) that defines the data layout and barcode formats for boarding passes worldwide.
Why do boarding passes use PDF417 instead of QR?
The IATA standard fixed PDF417 for printed passes when it was set, and its elongated shape suits the boarding-pass strip while every airport scanner already supports it. Mobile passes, which are read off a phone, are free to use a square matrix code such as Aztec or QR.