Driver’s License Barcode
The barcode on the back of a North American driver license is a PDF417 symbol containing a structured text record of what is printed on the front. Scanning it returns typed data in a fraction of a second, which is why it has become the default way to read a license — and why it is also the most attractive single target for anyone forging one.
| Symbology | PDF417, a stacked two-dimensional barcode |
| Data format | AAMVA DL/ID Card Design Standard |
| Location | Reverse of the card |
| Typical contents | Name, address, date of birth, license number, expiry, issue date, physical descriptors |
| Capacity | Well over a thousand characters |
| Signed | No |
| Also present on some cards | A magnetic stripe, largely deprecated |
Why the data is duplicated
The barcode does not contain anything the front of the card does not already show. That redundancy is the entire point.
Reading printed text from a license means handling fifty-plus card designs, each with its own layout, typeface, and background artwork. Reading a barcode means running one parser. The data arrives typed, structured, and field-labeled, with no transcription risk and no design variation to accommodate.
It also creates a comparison. Two independent representations of the same facts sit on one card, and they should match. When a forger alters the printed front of a genuine license — still a common and cheap attack — the barcode keeps saying what it always said.
Why the barcode matters for identity verification
In North America the barcode is the machine-readable layer. There is no machine-readable zone and usually no chip, so the PDF417 symbol carries the structured data that an MRZ carries on a passport.
The cross-check it enables is the most valuable thing about it. Printed front against encoded back, with any mismatch flagged — a photograph swapped, a date of birth altered, an address changed — is a fast, cheap fraud signal available before any deeper analysis runs. That comparison sits early in every identity document verification pipeline operating in the US or Canada.
The failure mode nobody expects
Here is the counterintuitive part. As barcode-based checking became standard, forgers adapted, and the adaptation was to make the barcode correct.
A modern counterfeit does not carry a mismatched barcode. It carries one generated from the same false data printed on the front, so the two agree perfectly. The cross-check passes. What gives these away is not disagreement between front and back but the barcode itself being too clean — encoding choices, field ordering, and version handling that a real DMV printer would not produce. The tell is the perfection.
Which means barcode parsing alone stopped being sufficient some time ago. It remains necessary; it is no longer the whole check.
What a driver’s license barcode can’t do
It carries no signature. Unlike a passport chip, an AAMVA barcode has no cryptographic proof of issuance. It can be generated by anyone with the published spec.
It does not prove the card is real. Physical security features — the substrate, the laminate, the optically variable elements — are what indicate genuine issuance, and none of them are in the barcode.
It does not prove the holder is the owner. That requires matching a live face against the photograph, with liveness detection to defeat a printed or replayed image.
It can be damaged. Wear, scratches, and worn laminate degrade the symbol. PDF417 carries error correction and tolerates a surprising amount, but a badly worn card will still fail to scan.
Frequently asked questions
What information is in a driver’s license barcode?
Typically name, address, date of birth, license number, issue and expiry dates, and physical descriptors such as height, eye color, and sex — essentially the same data printed on the front, in structured form.
Is the barcode encrypted?
No. It is plain structured text following the AAMVA standard. Anyone with a scanner can read it, and anyone with the published specification can generate a valid one.
Why does my license also have a magnetic stripe?
Legacy. Some jurisdictions issued cards with both, and the stripe carried a smaller subset of the same data. It has been largely displaced by the barcode, which holds far more and is cheaper to produce.
Does scanning the barcode verify the license?
No. It extracts data quickly and accurately, and lets you compare that data against the printed front. Verifying that the card was genuinely issued requires checking physical security features, and verifying the holder requires biometric matching.
