MRZ (Machine Readable Zone) Explained: Complete Guide to the Machine Readable Zone in Passports and ID Documents

 

What Is MRZ? (Machine Readable Zone Definition)

The Machine Readable Zone (MRZ) is a standardized section of a passport or ID document that contains encoded identity data. It allows border control, immigration systems, and identity verification platforms to read key information quickly and accurately using special scanners.

MRZ is a key component of modern travel documents and is mandated by ICAO (International Civil Aviation Organization) in more than 190 countries worldwide. It is used in:

  • biometric passports

  • machine-readable passports

  • national ID cards

  • residence permits

  • visas

  • work permits

  • some driver’s licenses

Why the MRZ Exists: Purpose and Importance

The MRZ is designed to make identity verification:

1. Faster

Automated systems scan the MRZ in a fraction of a second.

2. More accurate

Manual data entry is error-prone; MRZ eliminates such mistakes.

3. More secure

Standardized structure and check digits prevent document tampering.

4. Globally compatible

All compliant countries use the same ICAO format.

5. Required for biometric access

The MRZ unlocks the passport’s electronic chip (BAC — Basic Access Control).

Where the MRZ Is Located on Different Documents

The exact position depends on the document type:

  • Passports: bottom of the main photo/data page

  • National ID cards: usually on the back side

  • Visas: bottom of the visa sticker

  • Residence permits (e.g., Green Card, EAD): typically on the reverse side

The MRZ always uses:

  • 2 or 3 lines

  • OCR-B font

  • Latin letters only

  • digits

  • the < filler character

This makes it universally compatible with scanning devices worldwide.

MRZ Formats (ICAO Standards)

ICAO defines the following MRZ formats:

TD3 (Passports)

  • 2 lines × 44 characters

  • Used in nearly all biometric and machine-readable passports

TD1 (ID Cards, Residence Permits)

  • 3 lines × 30 characters

  • Used in most national ID cards

TD2 (Some Plastic ID Documents)

  • 2 lines × 36 characters

These formats ensure consistency and prevent ambiguity.

What Information the MRZ Contains

The MRZ encodes essential identity information in a strict, fixed layout.

Typical MRZ fields include:

  • Document type (P for passport, I for ID, V for visa)

  • Issuing country (three-letter ICAO code)

  • Document number

  • Check digit for document number

  • Holder’s surname and given names

  • Date of birth + check digit

  • Sex

  • Expiration date + check digit

  • Nationality

  • Final composite check digit

Because layout and character positions are fixed, scanners always know exactly where each data field is located.

How MRZ Check Digits Work (Security Mechanism Explained)

Check digits are one of the core security elements of the MRZ.

They verify:

  • passport number

  • date of birth

  • document expiration date

  • overall MRZ consistency

How the check digit is calculated:

  • Each character gets a numeric value

  • A repeating weight sequence is applied: 7, 3, 1

  • The sum of products is divided by 10

  • The remainder becomes the check digit

This prevents document forgery: even a small change creates a mismatch.

Why MRZ Is Difficult to Forge

1. Strict formatting rules

Any incorrect spacing, number of characters, or structure is immediately detected.

2. Check digits

Forging the MRZ requires accurately recomputing all check digits.

3. OCR-B machine-readable font

Designed for scanners, almost impossible to fake without detection.

4. Cross-checking

Systems compare the MRZ to the printed (visual) zone.

5. Biometric chip connection

In e-passports, MRZ is necessary for Basic Access Control (BAC) to read the chip.

MRZ Use Cases: Where and Why It’s Needed

1. Border Control & Airports

  • Automated passport gates (e-Gates)

  • Immigration checkpoints

  • Travel document validation

2. Airlines

  • Check-in

  • Boarding pass issuance

  • Visa verification

3. Digital Identity Verification

  • Banks

  • Fintech and payment services

  • KYC (Know Your Customer) systems

  • Online identity validation

4. Mobile Applications

  • Passport scanning apps

  • eSIM activation

  • Identity verification apps

MRZ in Biometric Passports (e-Passports)

In biometric passports, the MRZ plays an additional critical role:

  • The MRZ is used to generate a key to unlock the encrypted chip.

  • Without scanning the MRZ, the chip cannot be accessed.

  • This prevents unauthorized remote reading (skimming).

MRZ in U.S. Documents

U.S. documents that contain MRZ:

  • U.S. passports

  • U.S. visas

  • Green Card (Permanent Resident Card)

  • Employment Authorization Document (EAD)

Most U.S. driver’s licenses do not include an MRZ.

MRZ and Privacy: What Information It Does NOT Contain

The MRZ does not include:

  • home address

  • place of birth

  • biometric data

  • fingerprint information

  • chip contents

It contains only essential identification data — not sensitive personal details.

Example of a Passport MRZ (TD3)


 

P<USAJOHNSON<<MICHAEL<ROBERT<<<<<<<<<<<<<<<<

1234567890USA8001018M3001012<<<<<<<<<<<<<<06

This example includes the document number, country code, name, date of birth, expiration date, and check digits.

SEO FAQ: MRZ Common Questions (Optimized for Featured Snippets)

What is an MRZ in a passport?

The MRZ is the Machine Readable Zone that contains encoded identity data used for fast, automated scanning at borders and airports.

What information is stored in the MRZ?

It contains the holder’s name, passport number, nationality, date of birth, expiration date, and several check digits.

Is MRZ the same as a biometric chip?

No. MRZ is printed text; the chip is electronic. The MRZ is used to unlock chip access.

Can someone steal my identity by scanning my MRZ?

No. The MRZ contains basic identity data only — no address, biometrics, or sensitive information.

Why is the MRZ important?

It enables fast border processing, reduces errors, improves security, and ensures global compatibility.

 

Conclusion

The MRZ is an essential part of modern identity documents. It enables fast scanning, enhances security, supports biometric verification, minimizes human errors, and ensures global interoperability. Whether traveling internationally, passing border control, or verifying identity online, the MRZ plays a critical role in secure, efficient identification.

 

Where you can calculate MRZ?

The best MRZ calclulator