ID Card

The Polish national identity card number (numer dowodu osobistego) consists of three uppercase letters followed by six digits, where the final digit is a checksum computed using the ICAO 9303 weighted algorithm. The letters O and Q are excluded from the series.

Usage

use SlashLab\Numerik\Numerik;

// Boolean validation
Numerik::idCard()->isValid('ABC123454');   // true

// Lowercase input and hyphens are stripped during normalisation
Numerik::idCard()->isValid('abc-123-454');   // true

// Rich result
$result = Numerik::idCard()->validate('ABC123454');
$result->isValid;   // true

// Parse to value object
$idCard = Numerik::idCard()->parse('ABC123454');

// Null on failure instead of exception
$idCard = Numerik::idCard()->tryParse('bad-input'); // null

Value object API

parse() returns a SlashLab\Numerik\ValueObjects\IdCard instance or throws on failure. tryParse() returns a SlashLab\Numerik\ValueObjects\IdCard instance or null if parsing fails.

Core

Method	Return type	Description
getRaw()	string	The original input, untouched.
getNormalized()	string	3 uppercase letters + 6 digits, e.g. ABC123454.
__toString()	string	Same as getNormalized().

Structure

Method	Return type	Description
getSeries()	string	First 3 letters — the document series, e.g. ABC.
getSequentialNumber()	string	5-digit sequential number (positions 4–8), e.g. 12345.
getCheckDigit()	string	Single check digit at position 9, e.g. 4.

Examples

$idCard = Numerik::idCard()->parse('ABC123454');

$idCard->getRaw();                // 'ABC123454'
$idCard->getNormalized();         // 'ABC123454'
$idCard->getSeries();             // 'ABC'
$idCard->getSequentialNumber();   // '12345'
$idCard->getCheckDigit();         // '4'

// Lowercase and hyphens normalise to the same value
$idCard = Numerik::idCard()->parse('abc-123-454');

$idCard->getRaw();                // 'abc-123-454'
$idCard->getNormalized();         // 'ABC123454'

Validation algorithm

1. Reject inputs over 32 characters; fail with InvalidLength.
2. Strip spaces and hyphens. Convert to uppercase.
3. Assert exactly 9 characters remain; fail with InvalidLength.
4. Assert the first 3 characters are letters; fail with InvalidCharacters.
5. Assert the series contains no O or Q; fail with InvalidFormat.
6. Assert characters 4–9 are digits; fail with InvalidCharacters.
7. Apply the ICAO 9303 checksum over positions 1–8; fail with InvalidChecksum if the result does not match position 9. See Algorithms.

Failure reasons

Reason	Value	When
InvalidLength	invalid_length	Number is not exactly 9 characters after normalisation, or raw input exceeds 32 characters.
InvalidCharacters	invalid_characters	Non-letter characters in the series, or non-digit characters in the number portion.
InvalidFormat	invalid_format	Series contains the letter O or Q.
InvalidChecksum	invalid_checksum	ICAO 9303 check digit does not match.

Related

• Passport — same ICAO 9303 checksum algorithm; identifies the same person in an international context.
• PESEL — universal personal identifier linked to the same individual.