The MRZ code or Machine-Readable Zone (Zona legible por la máquina) is a set of alphanumeric strings that usually appear on the back of identity documents or passports.
It’s a way to encode personal information in an alphanumeric code so that any machine or smartphone can read and convert this code into relevant information. Virtually all passports and identity documents are equipped with an MRZ.
For these alphanumeric character strings, a special font (OCR-B) is used for reading them by intelligent devices.
In addition to the alphanumeric code, the MRZ uses a special font called OCR-B that facilitates automatic reading by cameras and scanners, even under conditions of tilt or poor image quality. This allows mobile devices and integrated systems to read and process information quickly and accurately, enabling seamless integration of automatic validation protocols at airports, access control systems, or digital platforms.
Since October 2025, the European Union has implemented the Entry/Exit System (EES), which replaces the physical passport stamp with an electronic record of entries and exits. This system also includes the collection of biometric data (fingerprints and facial photographs) to enhance security and migration oversight.
Contenido
The MRZ code, within its alphanumeric strings, contains the following data:
Each element of the MRZ is accompanied by a control digit calculated using standard algorithms to detect reading errors and prevent fraud. Additionally, validation systems compare this data with official databases and international templates to ensure document authenticity and internal consistency, which is essential to prevent forgeries or alterations.
The organization that regulates the information contained in the MRZ code is the International Civil Aviation Organization (ICAO), known in English as International Civil Aviation Organization (ICAO).
The ICAO establishes standards and recommendations for issuing travel documents, including passports and visas. These standards are outlined in Document 9303 titled “Machine Readable Travel Documents”, which details the technical specifications for machine-readable documents and establishes technical specifications and standards for travel documents, including passports and visas.
Document 9303 covers various aspects, such as:
This standard is adopted internationally to ensure interoperability and security of travel documents.
The MRZ code has several applications, mainly in the field of security and border management. Here are some of the most common uses:
Passport control machines at airports scan the MRZ to verify the passport’s authenticity and the traveler’s identity quickly and accurately.
Visas also contain an MRZ that facilitates their verification and authentication at a country’s entry points.
In eGates or electronic gates, the MRZ is used to enable automated passenger entry, reducing wait times and increasing border control efficiency.
Online check-in: Thanks to the Check-in Scan platform, hotels can quickly register passport or ID data of guests, streamlining the check-in process.
Currently, many hotels, airports, and government agencies use automated systems that scan the MRZ to handle check-ins, guest registration, and access control, speeding up processes and reducing human error. These technologies integrate with official databases and biometric systems to securely verify user identity efficiently.
In facilities such as nuclear plants or government buildings, the MRZ can be used as part of access control systems to ensure only authorized persons can enter.
By providing a standardized and secure way to encode personal information, the MRZ helps prevent the fraudulent use of forged travel documents.
