AAMVA field errors — what they are and why they matter

AAMVA (American Association of Motor Vehicle Administrators) defines the data format for US driver's license barcodes. Field format errors in this data are one of the most common vendor quality issues that are not visible to the naked eye but are detectable by scanning applications.

The AAMVA data structure

A PDF417 barcode on a US driver's license contains a structured data payload with specific field designators (three-letter codes like DCS for surname, DAC for first name, DBB for date of birth) followed by field values. Each field has a specified format — dates in MMDDYYYY format, names in uppercase, certain fields with maximum length limits. Deviating from these specifications produces a technically readable barcode that fails validation checks in applications that verify field format compliance.

Common errors

Date format errors are the most frequent: a date of birth entered as YYYY-MM-DD instead of MMDDYYYY format, or with separators that the specification does not permit. Name format errors include lowercase characters, spaces where not expected, or incorrect delimiter characters between name parts. State code errors occur when vendors use the wrong two-letter abbreviation for fields that reference the issuing state.

How to check for them

Several free online tools parse AAMVA barcode data. Search for "AAMVA barcode decoder" and you will find web tools that take a scanned barcode image or decoded string and display each field separately with its designator. Check that the date format, name format, and state codes match AAMVA specifications for the issuing state.

Scanner apps like Cognex decode the barcode but do not validate field formats — a field error passes Cognex but fails in ID Vibes or similar verification-focused apps. Checking the decoded data against AAMVA specifications is the only way to catch this type of error before use.

The most common AAMVA encoding error in vendor cards is an incorrect jurisdiction code in the header, which causes some scanner apps to display a wrong state name before displaying the decoded fields. This header mismatch is caught by any app that validates jurisdiction against the card's visual state indicator. It is not always a disqualifying problem, but it is the type of error that a systematic barcode check will reveal.