Passport MRZ: how to read and decode the two lines
The two lines of characters at the bottom of a passport’s personal data page form the Machine Readable Zone (MRZ).
They contain essential information about the passport holder and the document, including the holder’s identity, nationality, passport number and expiry date.
But how do you interpret these characters? What do the letters, numbers and symbols in this zone mean?
In this article, discover how to read a passport MRZ, understand the information it contains and identify the checks that can be performed.
Where is the MRZ located on a passport?
The MRZ is located at the bottom of the passport’s personal data page, below the holder’s personal information and photograph.
On TD3-format passports, it consists of two lines of 44 characters each, including letters, numbers and the < symbol.
This standardised structure, defined by the International Civil Aviation Organization (ICAO), allows automated reading systems to quickly extract information from the document, particularly during border checks.
To understand the differences between MRZ formats, read our article about the MRZ on identity cards.
How to read and decode the two lines of a passport MRZ
A passport MRZ is read from left to right, across two lines. Each character occupies a specific position and corresponds to information defined by international standards.
Let’s take the following fictional example:
Line 1:
P<FRADUPONT<<MARIE<LOUISE<<<<<<<<<<<<<<<<<<<<
Line 2:
AB12345671FRA9004159F3006302<<<<<<<<<<<<<<02
First line: document type, issuing country and identity
The first line identifies the document type, the country that issued it, and the holder’s surname and given names.
In our example:
- P: indicates that the document is a passport.
- FRA: is the issuing country’s code, in this case France.
- DUPONT: the holder’s surname.
- MARIE LOUISE: the holder’s given names.
The < characters are used to separate information or fill unused positions.
Second line: passport number, dates and check digits
The second line contains information used to identify the passport and check the consistency of certain data.
| Position | Information | Value in the example |
|---|---|---|
| 1–9 | Passport number | AB1234567 |
| 10 | Passport number check digit | 1 |
| 11–13 | Nationality | FRA |
| 14–19 | Date of birth | 900415 (15 April 1990) |
| 20 | Date of birth check digit | 9 |
| 21 | Sex | F |
| 22–27 | Expiry date | 300630 (30 June 2030) |
| 28 | Expiry date check digit | 2 |
| 29–42 | Optional data | Not provided |
| 43 | Optional data check digit | 0 |
| 44 | Composite check digit | 2 |
Dates are recorded in YYMMDD format: two digits for the year, two for the month and two for the day.
Additional check digits are used to verify the consistency of the data encoded in the MRZ. Their purpose is explained in the following section.
What do the characters and symbols in the MRZ mean?
A passport MRZ uses only uppercase letters, digits from 0 to 9 and the < symbol. This standardisation allows automated reading systems to interpret the information consistently.
What is the < symbol used for in the MRZ?
The < symbol, known as a filler character, serves several purposes:
- Separating surnames and given names: two consecutive characters (<<) mark the separation between these fields.
- Replacing spaces: a single < can separate multiple given names or different parts of a surname.
- Filling unused positions: empty positions are filled with this character to maintain a fixed length of 44 characters per line.
In our example, DUPONT<<MARIE<LOUISE identifies the holder’s surname and two given names.
What are check digits used for?
The MRZ also contains several check digits, calculated from specific passport information.
They help verify the consistency of the passport number, date of birth and expiry date.
The calculation follows a standardised method that assigns a value to each character and applies a series of weighting factors.
In our example, the date of birth 900415 has a check digit of 9, calculated using this method.
An incorrect check digit may indicate a reading error, a data entry mistake or an alteration of the information. However, valid check digits alone do not guarantee that a passport is authentic.
What checks can be performed using the MRZ?
A passport MRZ does more than facilitate automated data reading. It also enables several data consistency checks to identify potential errors or anomalies.
The main checks include:
- Data consistency: comparing the information extracted from the MRZ with the details printed on the passport’s personal data page.
- Date validity: checking the document’s expiry date and the consistency of the encoded dates.
- Check digit validation: recalculating check digits to detect potential errors or inconsistencies.
Does a valid MRZ guarantee that a passport is authentic?
No. A correctly structured MRZ with valid check digits does not guarantee that a passport is authentic.
Check digits verify data consistency, but they do not provide proof of authenticity. An MRZ can be reproduced or falsified while still following the correct calculation rules.
Detecting potential document fraud may require additional checks, including examining the passport’s security features and verifying the holder’s identity.
How can CheckHub automate passport MRZ reading and verification?
For businesses that regularly collect and verify passports, manually reading MRZ data can quickly become time-consuming and prone to errors.
With CheckHub, businesses can automate passport data extraction, perform document checks and verify the identity of passport holders.
The platform enables businesses to:
- Read and extract data: use OCR technology to identify passport information, including the data contained in the MRZ.
- Perform document checks: analyse extracted information and carry out checks to identify potential inconsistencies or anomalies.
- Verify the holder’s identity: compare the passport photo with a selfie using facial recognition and liveness detection.
- Automate document collection and follow-up: centralise passports and other required documents, track their validity and automate renewal requests.
CheckHub helps businesses reduce administrative work related to passport processing while improving the reliability of document verification.