NIP

NIP (Numer Identyfikacji Podatkowej) is Poland’s 10-digit tax identification number, used by both individuals and legal entities.

Usage

use SlashLab\Numerik\Numerik;

// Boolean
Numerik::nip()->isValid('5260250274');   // true

// Rich result
$result = Numerik::nip()->validate('5260250274');
$result->isValid;   // true

// Parse to value object
$nip = Numerik::nip()->parse('5260250274');

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

NIP accepts hyphens and spaces as separators in the input:

Numerik::nip()->isValid('526-025-02-74');   // true
Numerik::nip()->isValid('526 025 02 74');   // true

Value object API

parse() and tryParse() return a SlashLab\Numerik\ValueObjects\Nip instance.

Core

Method	Return type	Description
getRaw()	string	The original input, untouched.
getNormalized()	string	10 raw digits (hyphens and spaces removed).
__toString()	string	Same as getNormalized().

Formatting & metadata

Method	Return type	Description
getFormatted()	string	Canonical NNN-NNN-NN-NN display form.
getFormattedAlternative()	string	Alternative NNN-NN-NN-NNN display form used by some legal entity documents.
getTaxOfficeCode()	string	First 3 digits — indicates the issuing tax office.

Examples

$nip = Numerik::nip()->parse('5260250274');

$nip->getRaw();                       // '5260250274'
$nip->getNormalized();                // '5260250274'
$nip->getFormatted();                 // '526-025-02-74'
$nip->getFormattedAlternative();      // '526-02-50-274'
$nip->getTaxOfficeCode();             // '526'

// With formatted input
$nip = Numerik::nip()->parse('526-025-02-74');
$nip->getRaw();            // '526-025-02-74'
$nip->getNormalized();     // '5260250274'

Failure reasons

Reason	Value	When
InvalidLength	invalid_length	Input is not exactly 10 digits after stripping separators.
InvalidCharacters	invalid_characters	Characters other than digits, hyphens, and spaces are present.
InvalidFormat	invalid_format	First 3 digits are 000 (no valid tax office has code 000).
InvalidChecksum	invalid_checksum	Checksum digit does not match.
AllSameDigit	all_same_digit	All digits are identical — strict mode only.

Validation algorithm

Weights: 6, 5, 7, 2, 3, 4, 5, 6, 7

1. Strip hyphens and spaces. Assert exactly 10 digits.
2. Assert the first 3 digits are not 000.
3. Multiply each of the first 9 digits by its weight, sum, take mod 11. The result must equal digit 10. If the modulo result is 10, the number is structurally invalid — no valid NIP can have a checksum digit of 10.

See Algorithms for the full reference.