What Is MRZ?

A Machine-Readable Zone (MRZ) is a key security feature found on passports, ID cards, visas, and other identification documents. It encodes specific information about the document holder, allowing machines to scan, read, and verify identity data efficiently. Initially developed to speed up border and airport checks, MRZs have become essential for identity verification across multiple sectors. This guide will walk you through what an MRZ is, its structure, and how it functions in document verification.

What is an MRZ Code?

The MRZ on an ID document is a standardized code created by the International Civil Aviation Organization (ICAO) in the 1980s. Since November 24, 2015, non-machine-readable passports are no longer valid in the 193 ICAO Member States. Typically located at the bottom of a document’s personal data page, an MRZ consists of one to three lines of characters, depending on the document type and the issuing country.

The ICAO’s Doc 9303 standardizes the MRZ format across countries, ensuring consistency in parameters like character style, size, and spacing. Information encoded in the MRZ generally includes:

• Document number
• Expiration date
• Holder’s name
• Gender
• Date of birth
• Nationality

Example: MRZ in a Finnish Passport

In a Finnish passport, the MRZ begins with a code indicating the type of document—‘P’ for passport, ‘V’ for visas, ‘D’ for driver’s licenses, and ‘I’ for ID cards. The first line also contains the issuing country’s code and the holder’s name, using fillers (<) if needed. The second line includes the document number, nationality, date of birth, gender, expiration date, and personal identifier, with check digits for added security. For biometric passports, the MRZ also serves as a key to the RFID chip, enabling NFC-based verification.

Purpose of a Machine-Readable Zone

The MRZ provides a reliable way to confirm someone’s identity while preventing unauthorized access to secure areas or systems. Using a standardized format, MRZs are readable across identity verification tools worldwide, converting diverse character sets into a uniform Latin text. MRZs aren’t limited to travel documents; they’re also found in documents like vehicle registrations, work permits, and voter cards. Some countries enhance MRZ security by printing it in ink that’s visible only under UV light.

Common Use Cases for MRZ Reading

• Automated Check-In at Airports and Hotels
• Data Entry Automation
• Age Verification
• Customer Onboarding
• Know Your Customer (KYC) Compliance
• Fraud Prevention

Types of Machine-Readable Zones

MRZ formats vary based on the type of document:

1. ID1 (TD1): Commonly used in driver’s licenses and ID cards, featuring one to three lines of 30 characters each.

2. ID2 (TD2): Used in visas, consisting of two lines with 36 characters each.

3. ID3 (TD3): Standard in passports, with two lines of 44 characters each.

Most ID verification tools support these formats, though some documents, like Swiss driver’s licenses with two lines of 30 characters, may require specialized software.

How Machines Read MRZ Codes

MRZ reading follows a three-step process:

Capture and Scanning: The MRZ is captured by a reader or OCR software, even if the document is angled or low resolution. Advanced systems can scan documents under various lighting, such as infrared, to reveal overprinting or signs of forgery.

Data Extraction: OCR algorithms then structure the MRZ data, extracting essential details like the document number and expiration date. Specialized parsers can detect non-standard formats, handling unique data fields added by specific countries.

Data Verification and Cross-Validation: Finally, the extracted data is validated by comparing each field against its expected format. For instance, check digits—calculated according to ICAO standards—confirm the MRZ’s authenticity. Cross-referencing MRZ data with the visible information on the document (e.g., name, birth date) ensures accuracy and detects discrepancies. At this stage, biometric MRZ data can also be verified against RFID chip information for added security.

Conclusion

Machine-readable zones provide a fast and reliable way to verify identities, supporting secure processes in various industries. Understanding MRZ formats, types, and verification methods is crucial for organizations that rely on accurate and efficient identity verification. With robust MRZ reading capabilities, businesses can enhance security, reduce fraud, and streamline customer interactions across multiple use cases.