Machine-readable zone (MRZ)

What is a machine-readable zone in simple words

A machine-readable zone (MRZ — Machine Readable Zone) is a special area in a passport or other identification document that contains alphanumeric information in a format understandable by computers. These are the two or three lines with letters and numbers that you see at the bottom of the page with the photo.

The MRZ allows document data to be read automatically without manual entry. When you pass passport control at the airport, the scanner reads this zone in a fraction of a second, extracting all the necessary information: your name, surname, passport number, date of birth, validity period and other data. This speeds up the verification process and reduces the risk of human error.

Machine-readable zone standards are developed by the International Civil Aviation Organization (ICAO) and are described in ICAO Doc 9303, which defines uniform requirements for machine-readable travel documents (MRTD) worldwide. Thanks to these standards, passports issued in different countries can be read by the same equipment.

It is important to note that the MRZ is present not only in foreign passports, but also in national identity documents, visas, residence permits and other documents. This makes the technology universal and applicable in a wide variety of scenarios — from bank identification to access control at secure facilities.

MRZ structure

The most common format is TD3 (used in foreign passports) — two lines of 44 characters each. The first line contains:

• Document type (for example, P — passport);
• Country code of the issuing state (three-letter code per ICAO standard);
• Surname and given name of the holder (separated by the special filler character "<").

The second line contains:

• Document number (series and passport number);
• Nationality (three-letter code);
• Date of birth (in YYMMDD format);
• Sex (M — male, F — female);
• Document validity period (in YYMMDD format);
• Check digits for data validation.

Check digits are an important protection element. They are calculated by a special algorithm and allow detecting entry errors or forgery attempts. If a check digit does not match the calculated value, the system signals a possible problem.

There are also TD1 formats (used in ID cards) — three lines of 30 characters, and TD2 (used in visas) — two lines of 36 characters. Each of these formats has its own structure, but they all follow the general principles established by ICAO.

Understanding the MRZ structure is important for specialists working with document identification and verification systems. Incorrect placement of characters or errors in check digits can lead to failures in automated systems. That is why special attention is paid to recognition accuracy when developing MRZ reading equipment.

MRZ reading

Special scanners and software that recognize characters of the OCR-B font are used to read the machine-readable zone. This font is specially designed for optimal character recognition by machines — each character has a unique shape that prevents confusion.

Automated workstations such as APM-1 and APM-2 are equipped with optical sensors and specialized software for MRZ recognition. The SPV-7024M equipment provides fast scanning and check digit verification, which is especially important at high-throughput checkpoints.

The MRZ reading process takes a fraction of a second and is fully automated. The scanner takes a picture of the document, recognizes the characters in the machine-readable zone, verifies the check digits and transfers the data to the information system. This significantly speeds up the identification process and reduces the load on employees performing document verification.

MRZ reading is used not only at borders, but also in banks, hotels and enterprises with high security requirements. For example, when checking into a hotel, an employee can scan a guest's passport, and all data will be automatically entered into the system. This eliminates entry errors and speeds up the registration process.

The design service includes integration of MRZ reading systems with the organization's existing IT infrastructure. This may include configuring interaction with databases, access control systems and other information security components. Read more about solutions in the technologies section.