MRZ formats: the ID card MRZ (TD1), TD2, TD3 passports and MRV visas

Published 2026-11-02 · By the Koncile team

An ID card MRZ is usually three lines of 30 characters (format TD1); a passport has two lines of 44 (TD3); TD2 cards and MRV-B visas use two lines of 36, MRV-A visas two lines of 44. The size of the document decides the format, and the first letter (I, A, C, P or V) confirms it. Below: which real documents use which format, every layout position by position, and the cases that break parsers.

ID card MRZ or passport MRZ: how to tell in two seconds

Count the lines, then count the characters on one line. Those two numbers are enough to name the format, because ICAO 9303, the international standard for machine readable travel documents, gives each document size its own layout. The machine readable zone (MRZ) of an ID card is almost always three lines of 30 characters; a passport always has two lines of 44.

The first character confirms the guess. P opens a passport, V a visa, and I, A or C an ID card or another official travel document. A two line zone of 44 characters starting with V is therefore a visa, not a passport, even though both share the same line length.

For what each character means on a passport, the basics are in our guide to the machine readable zone. This page compares the five layouts side by side, shows which real documents use which, and lists the traps that make a parser fail on a valid card.

Which document uses which MRZ format

The format follows the size of the document, not its country. Some families are fixed by law, which makes them predictable for anyone who processes documents at scale:

Two lessons come out of this table. First, the line length alone is not a reliable country or document detector: the old French card and the TD2 format share 36 characters per line but not the same field order. Second, a card without an MRZ is common outside travel documents, so a reading flow has to fall back on the printed fields of the visual inspection zone (VIZ).

The ID card MRZ (TD1), position by position

TD1 is the format behind the query « mrz id card ». It spreads the data over three short lines, and the order is not the passport order: the document number comes first, on line 1, and the name moves down to line 3. Here is the ICAO specimen card, with valid check digits:

I<UTOD231458907<<<<<<<<<<<<<<<
7408122F1204159UTO<<<<<<<<<<<6
ERIKSSON<<ANNA<MARIA<<<<<<<<<<

The composite digit at the end of line 2 covers line 1 from position 6 to 30 and line 2 from 1 to 7, 9 to 15 and 19 to 29: everything except the document code, the issuing state, the sex and the nationality. The optional data of a TD1 card has no check digit of its own, which is why some issuers store a second number there that only the composite protects. The arithmetic behind each digit is explained in our guide to the MRZ checksum on ID cards and passports.

Long document numbers on TD1 cards

Nine positions are not always enough. When a card number has more than 9 characters, Doc 9303 part 5 puts the first 9 at positions 6 to 14, a filler « < » at position 15 where the check digit would be, then the rest of the number followed by its check digit at the start of the optional data. A parser that always reads position 15 as a digit rejects these cards or returns a truncated number, and the error only shows on a few countries, which makes it hard to catch in testing.

A name squeezed into 30 characters

Line 3 holds the whole name in 30 positions, against 39 on a passport. Long names are cut, and Doc 9303 part 3 sets how: given names are shortened first, then the surname if needed. The MRZ name of a TD1 card is therefore often shorter than the printed name, so a strict equality test between the two fields flags genuine cards. A comparison that accepts truncation and transliteration (Ü written UE or U) avoids those false alarms.

The passport MRZ (TD3) in one table

The passport format is the most common and the most documented. The ICAO specimen reads:

P<UTOERIKSSON<<ANNA<MARIA<<<<<<<<<<<<<<<<<<<
L898902C36UTO7408122F1204159ZE184226B<<<<<10

Compared with TD1, the passport keeps the name on line 1, places the nationality right after the document number, and gives the personal number its own check digit. Those three differences are the usual source of bugs when one parser is reused for both families.

The TD2 format, between card and passport

TD2 has the order of a passport with the lengths of a smaller card: the name field shrinks to 31 positions and the optional data to 7. It is now rare on new ID cards but still turns up on older cards and on some residence and official travel documents. The specimen:

I<UTOERIKSSON<<ANNA<MARIA<<<<<<<<<<<
D231458907UTO7408122F1204159<<<<<<<6

Visa formats: MRV-A and MRV-B

A machine readable visa (MRV) is a sticker placed in a passport. Its zone looks like a passport or TD2 zone, starts with V, and has one structural difference: there is no composite check digit, and the optional data at the end of line 2 is not protected at all. MRV-A has two lines of 44, MRV-B two lines of 36 so that the sticker leaves room on the page.

MRV-A specimen
V<UTOERIKSSON<<ANNA<MARIA<<<<<<<<<<<<<<<<<<<
L8988901C4XXX4009078F96121096ZE184226B<<<<<<

MRV-B specimen
V<UTOERIKSSON<<ANNA<MARIA<<<<<<<<<<<
L8988901C4XXX4009078F9612109<<<<<<<<

The nationality XXX in the ICAO visa specimen is a real code: it marks a person of unspecified nationality. Other reserved codes appear on refugee and stateless documents, so a country list that only holds the ISO 3166 states rejects valid zones.

Document codes: what the first two characters say

The first character names the family and is fixed by Doc 9303: P for passports, V for visas, and I, A or C for ID cards and other official travel documents in TD1 or TD2 size. The second character is left to the issuing state. Many passports use « P< »; others use a letter to mark a diplomatic, service or emergency passport, with codes that vary from one country to the next.

This is the part of the standard that is moving. ICAO is revising Doc 9303 with a wider set of document codes so that ordinary, diplomatic, service, temporary and emergency passports can be told apart without a country table, plus stricter printing rules and stricter consistency between the MRZ and the printed page, as reported by Biometric Update in December 2025. Documents in both generations will circulate together for years, so a parser should treat the second character as information to return, not as a value to validate against a fixed list.

How a parser recognises the format

Format detection is the first step of any MRZ reader, before field splitting and check digits. A short version in Python, applied to the lines once the OCR has returned them:

def mrz_format(lines):
    lines = [l.strip().replace(" ", "") for l in lines if l.strip()]
    sizes = (len(lines), len(lines[0]) if lines else 0)
    first = lines[0][0] if lines else ""
    if sizes == (3, 30):
        return "TD1"
    if sizes == (2, 44):
        return "MRV-A" if first == "V" else "TD3"
    if sizes == (2, 36):
        return "MRV-B" if first == "V" else "TD2 (or a national 36 character layout)"
    return "unknown: check the crop and the line breaks"

mrz_format(["I<UTOD231458907<<<<<<<<<<<<<<<",
            "7408122F1204159UTO<<<<<<<<<<<6",
            "ERIKSSON<<ANNA<MARIA<<<<<<<<<<"])   # 'TD1'

The function was run on the five ICAO specimens quoted on this page. In production, the hard part is not the rule but the input. These are the cases that send a valid document to « unknown »:

• Lines merged or split by the OCR. A TD1 zone read as two lines of 45 characters, or a passport line cut in two, breaks the count. Joining all characters and testing the total length (90, 72 or 88) is a sturdier first test.
• Fillers read as letters. A « < » read as K or « « » changes nothing in the length but breaks every later step; a reader that knows the expected format can correct runs of fillers.
• The wrong side of the card. On most TD1 cards the MRZ is on the back. A front side alone has no MRZ, so the reading has to come from the printed fields, or the user has to send both sides.
• National layouts. The old French card and the Swiss licence need their own rules. Labelling them TD2 or TD1 produces fields that look plausible and are wrong.

What the format tells you, and what it does not

A zone with the right number of lines, the right lengths and valid check digits is a well formed MRZ. It is not proof that the document is genuine: the layout and the checksum algorithm are public, so an edited scan can carry a perfect zone. The checks that carry information sit around the MRZ: agreement between the MRZ and the printed fields, an expiry date in the future, a document code consistent with the document shown, traces of editing in a PDF file, signs of retouching in a photo.

Koncile reads the MRZ of passports, ID cards and residence permits in all of these formats, returns the lines and the parsed fields together with the printed fields, and adds a fraud score from 0 to 100 on the file. A score is a signal to verify, never an accusation, and the service does not read the chip, match faces or check liveness. The fields returned are described on the ID card OCR page.

Sources

• ICAO Doc 9303, part 3: specifications common to all MRTDs (check digits, name truncation, transliteration)
• ICAO Doc 9303, part 4: machine readable passports (TD3)
• ICAO Doc 9303, part 5: TD1 size documents
• ICAO Doc 9303, part 6: TD2 size documents
• ICAO Doc 9303, part 7: machine readable visas (MRV-A, MRV-B)
• Regulation (EU) 2019/1157 on the security of identity cards and residence documents