MRZ (Machine-Readable Zone)
Definition
The lower portion of the passport biographical page printed in OCR-B font, structured according to ICAO 9303 TD3 format (two lines of 44 characters), machine-parsed by border readers and containing holder data with check digits.
- Location
- Passport biographical page, lower portion
- Font
- OCR-B
- Standard
- ICAO Doc 9303, TD3 format
- Structure
- Two lines of 44 characters
- Includes
- Check digits
Common questions
What are the check digits in the MRZ actually for?+
Each check digit is calculated from a weighted sum of the preceding characters in its field, so a border reader or forensic examiner can instantly verify whether a field, such as the passport number or date of birth, has been altered, since even a single-digit change will fail the checksum.
How does an examiner use the MRZ to detect a forged or altered passport?+
The examiner cross-checks MRZ data against the visually printed biographical data on the same page and against the check digit calculations; a mismatch between the printed name or date and the MRZ-encoded value, or a failed checksum, is a strong indicator of tampering.
Does every passport in the world use the same MRZ format?+
Most modern machine-readable passports follow the ICAO 9303 TD3 two-line, 44-character format, but other travel documents such as ID cards and visas use different TD1 or TD2 layouts with different line counts and lengths under the same overall standard.
Related terms
- BAC (Basic Access Control)
- The ICAO e-Passport access control mechanism that derives a session key from the MRZ data, requiring the passport to be physically opened...
- Check-Digit Algorithm
- A weighted-sum calculation (weights 7, 3, 1 cycling, modulo 10) over the character values of MRZ fields; used to detect data transcription...
- FADO (False and Authentic Documents Online)
- FRONTEX-managed EU database providing border officers with reference images of both genuine and known fraudulent travel documents from EU and associated states.
- ICAO 9303
- The International Civil Aviation Organization's Machine Readable Travel Documents standard (8th edition, 2021), specifying MRZ field structure, OCR-B font, check-digit algorithm, biometric...
- KINEGRAM
- A diffractive optically variable image device (DOVID) in holographic foil used on passport biographical pages and visa stickers; produced by OVD Kinegram...
- Passive Authentication (PA)
- The ICAO e-Passport mechanism by which a border reader verifies that chip data groups are signed by the issuing state's Document Signer...
- Photo Substitution
- A fraud type in which the original holder's photograph on a genuine document is replaced with the fraudster's image, typically by lifting...
- Polycarbonate Biographical Page
- A laser-engraved PC data page in which holder data and portrait are embedded within the polycarbonate layers rather than printed on the...
- SLTD Database
- INTERPOL's Stolen and Lost Travel Documents database, containing over 100 million records of passports and identity documents reported stolen or lost by...