ID card MRZ: what is it used for and how does it work?

What is the MRZ on an identity card?

The MRZ (Machine Readable Zone) is a standardized section of an identity document designed to be read automatically using optical character recognition technology.

It consists of several lines of alphanumeric characters, generally located on the back of modern identity cards.

It allows computer systems to quickly extract certain identity details without the need for manual data entry.

What information does the MRZ contain?

Depending on the type and format of the document, the MRZ may contain:

• The holder’s first and last name
• Date of birth
• Nationality
• Identity document number
• Expiration date
• Sex indicated on the document
• Check digits used to verify the consistency of certain data

This information follows a standardized format, making it easier for specialized software to read and process.

Do all identity cards have an MRZ?

No, not all identity cards necessarily have an MRZ. Its presence depends on factors such as the issuing country and the date the document was issued.

Since August 2, 2021, European regulations have required newly issued national identity cards in the EU Member States concerned to include a machine-readable zone. However, this technology was already used on certain older identity card models in many European countries.

Some older documents or identity cards issued in other countries may not have an MRZ. Therefore, the absence of an MRZ does not automatically mean that a document is fraudulent.

How to read and decode an ID card MRZ

An MRZ can be read automatically using OCR technology (Optical Character Recognition).

When an identity card is photographed or scanned, the system identifies the MRZ, recognizes its characters, and extracts the information it contains.

The process generally involves several steps:

1. MRZ detection: the software locates the lines of characters on the document.
2. Character recognition: OCR technology extracts the letters, numbers, and symbols.
3. Data interpretation: the extracted information is organized according to the document’s standardized format.
4. Consistency checks: certain fields are validated using check digits and can be compared with the information visible on the card.

This automation reduces manual data entry and makes it easier to process large volumes of documents.

The MRZ is also found on passports, where it consists of two lines of 44 characters each. Discover how to read and decode a passport MRZ in our dedicated article.

How is MRZ information verified?

The MRZ contains identity information as well as check digits used to verify the consistency of certain data.

During automated reading, software analyzes this information and checks whether the calculated check digits match those encoded in the MRZ. It can also compare the information extracted from the MRZ with the details visible on the identity card to detect potential inconsistencies.

However, a valid MRZ alone does not guarantee that a document is authentic. This is why MRZ reading should be complemented by other checks, such as analyzing the card’s security features or performing biometric verification.

Why can an identity card be rejected due to a damaged MRZ?

During remote identity verification, a damaged or unreadable MRZ can prevent the document from being read automatically.

Several factors can cause this issue:

• A damaged card: scratches, wear, or partially erased characters.
• Poor image quality: a blurry photo, insufficient resolution, or incomplete framing.
• Light reflections: direct lighting or camera flash obscuring certain characters.

When the software cannot extract the information correctly, the document may be automatically rejected or require manual verification.

This does not necessarily mean that the card is fraudulent. A poor-quality image alone can prevent the MRZ from being read.

Automate MRZ reading and verification with CheckHub

Manually verifying identity documents can quickly become time-consuming, particularly for companies managing large numbers of candidate or employee files.

With CheckHub, MRZ reading is integrated directly into automated identity verification processes, alongside other document verification and biometric technologies.

The solution offers several capabilities:

• Automated data extraction: using OCR technology, CheckHub extracts information from identity documents, including data contained in the MRZ.
• Consistency checks: information encoded in the MRZ can be compared with the details visible on the document to identify potential inconsistencies.
• Document fraud detection: CheckHub Reader combines different technologies to analyze documents and identify anomalies that may indicate fraud.
• Biometric verification: using face matching, CheckHub can compare a person’s face with the photo on their identity document to strengthen the verification process.
• On-site identity verification: with CheckHub Pass, companies can also confirm a person’s identity directly at their workplace, notably through biometric verification performed using a smartphone.

These features can be integrated into recruitment and onboarding workflows to automate checks, reduce manual intervention, and improve the security of identity verification processes.

Secure your identity verification processes

Looking to automate identity document verification for your candidates or employees?

Request a CheckHub demo to discover how to simplify and secure your identity verification processes.