Document Checks

Tuteliq validates documents at three levels: document number algorithms, MRZ check digits, and barcode data extraction. Each layer independently verifies the document’s integrity, and all layers are cross-referenced against each other.

Document number validation

Tuteliq validates document numbers using the actual government-defined algorithm for each country — not just format checks. This means a forged document with a made-up number that looks correct will still fail validation.

Supported countries (45)

Americas (8)

Brazil (CPF), Argentina (DNI), Mexico (CURP), Chile (RUT), Colombia (CC), Peru (DNI), Ecuador (CI), Uruguay (CI), Canada (SIN), United States (SSN)

Europe (22)

Sweden (personnummer), Spain (DNI/NIE), Netherlands (BSN), Portugal (NIF), Germany (Steuer-ID), France (NIR), Italy (Codice Fiscale), Belgium (NRN), Finland (PIC), Norway (fnr), Poland (PESEL), UK (NI Number), Ireland (PPS), Switzerland (AHV), Austria (SVNr), Czech Republic (RC), Romania (CNP), Croatia (OIB), Bulgaria (EGN), Greece (AFM), Hungary (Tax ID), Estonia, Lithuania, Latvia

Asia-Pacific (9)

Thailand (ID), Turkey (TC Kimlik), South Korea (RRN), India (Aadhaar), China (ID), Taiwan (ID), Japan (My Number), Australia (TFN), New Zealand (IRD)

Middle East & Africa (2)

Israel (ID), South Africa (ID)

Validation algorithms

Each country uses a specific check digit algorithm. Some examples:

Country	Document	Algorithm
Brazil	CPF	Weighted mod 11, two check digits
Sweden	Personnummer	Luhn algorithm on 10-digit form + date validation
India	Aadhaar	Verhoeff algorithm (dihedral group D5)
Spain	DNI/NIE	Mod 23 letter check
Germany	Steuer-ID	ISO 7064 Mod 11,10
France	NIR	Mod 97 (BigInt arithmetic for 15-digit numbers)
Italy	Codice Fiscale	Odd/even position lookup with omocodia handling
Belgium	NRN	Mod 97 with century detection
Croatia	OIB	ISO 7064 Mod 11,10
Switzerland	AHV	EAN-13 barcode check digit
US	SSN	Area/group/serial validation + known invalid rejection

Document number validation is automatic — when a document number and country code are detected, the appropriate algorithm runs without any configuration.

MRZ validation (ICAO 9303)

The Machine Readable Zone (MRZ) is present on passports and many national ID cards worldwide. Tuteliq implements full ICAO 9303 MRZ parsing with check digit validation.

Supported formats

Format	Lines	Characters	Used in
TD3	2 lines	44 chars each	Passports
TD2	2 lines	36 chars each	ID cards (some countries)
TD1	3 lines	30 chars each	ID cards (most countries)

What gets validated

Each MRZ contains multiple fields, each protected by its own check digit using the ICAO weighted mod-7 algorithm (weights cycle [7, 3, 1]):

Field	Check digit	What it catches
Document number	Per-field	Altered document number
Date of birth	Per-field	Altered birth date
Expiry date	Per-field	Altered expiry date
Personal number	Per-field	Altered personal data
Composite	Across all fields	Any tampering across the entire MRZ

The composite check digit is critical — even if someone correctly recalculates individual field check digits after altering a value, the composite check will fail unless they also recalculate it.

Extracted fields

When a valid MRZ is detected, Tuteliq extracts and returns:

Document number (with validation status)
Nationality / issuing state
Date of birth (with century detection)
Expiry date
Sex
Surname and given names
Personal number / optional data

All extracted fields are cross-referenced against OCR text from the visible part of the document.

PDF417 barcode reading

US and Canadian driver’s licenses encode all personal data in a PDF417 barcode on the back of the card following the AAMVA (American Association of Motor Vehicle Administrators) standard.

Why barcodes matter

The barcode data is independent of the printed text on the front. A forger who edits the front of a driver’s license (changing the name, DOB, or photo) must also modify the barcode — which requires specialized knowledge. Most forgeries only edit the visual side. When both sides are provided, Tuteliq:

Decodes the PDF417 barcode from the back image
Parses AAMVA fields (name, DOB, expiry, license number, sex, address, state)
Cross-references barcode data against OCR text from the front
Flags any mismatch as potential tampering
Falls back to barcode DOB/expiry when OCR fails to extract them

Extracted AAMVA fields

Field	AAMVA Code	Description
First name	DAC/DCT	Given name
Last name	DCS/DAB	Surname
Date of birth	DBB	MMDDYYYY format
Expiration date	DBA	MMDDYYYY format
Document number	DAQ	License/ID number
Sex	DBC	1=Male, 2=Female
Address	DAG/DAI/DAJ/DAK	Street, city, state, postal code
Country	DCG	Issuing country

Supported barcodes

Format	Used in
PDF417	US/Canadian driver’s licenses (primary target)
QR Code	Some international ID cards
DataMatrix	Some European ID cards

For best barcode reading results, provide the back of the document as a separate image using the document_back field. This allows dedicated barcode scanning without the front-side OCR processing interfering.

How the layers work together

Document Image
     |
     v
  +---------+     +----------+     +----------+
  |   OCR   |     |   MRZ    |     | Barcode  |
  | (labels)|     | (ICAO)   |     | (PDF417) |
  +---------+     +----------+     +----------+
     |                 |                 |
     v                 v                 v
  Name, DOB,      Name, DOB,       Name, DOB,
  Doc Number,     Doc Number,      Doc Number,
  Expiry,         Nationality,     Expiry,
  Country         Expiry, Sex      State
     |                 |                 |
     +---------+-------+---------+-------+
               |                 |
               v                 v
        Cross-Reference    Algorithmic
         All Sources       Validation
               |                 |
               v                 v
          Flag Any           Verify
         Mismatches        Check Digits

Any inconsistency between sources generates a specific failure reason that is included in the API response.

Document Checks

Document number validation

Supported countries (45)

Americas (8)

Europe (22)

Asia-Pacific (9)

Middle East & Africa (2)

Validation algorithms

MRZ validation (ICAO 9303)

Supported formats

What gets validated

Extracted fields

PDF417 barcode reading

Why barcodes matter

Extracted AAMVA fields

Supported barcodes

How the layers work together

Next steps

Liveness Detection

Fraud Prevention

​Document number validation

​Supported countries (45)

Americas (8)

Europe (22)

Asia-Pacific (9)

Middle East & Africa (2)

​Validation algorithms

​MRZ validation (ICAO 9303)

​Supported formats

​What gets validated

​Extracted fields

​PDF417 barcode reading

​Why barcodes matter

​Extracted AAMVA fields

​Supported barcodes

​How the layers work together

​Next steps

Liveness Detection

Fraud Prevention

Document number validation

Supported countries (45)

Validation algorithms

MRZ validation (ICAO 9303)

Supported formats

What gets validated

Extracted fields

PDF417 barcode reading

Why barcodes matter

Extracted AAMVA fields

Supported barcodes

How the layers work together

Next steps