KRS

KRS (Krajowy Rejestr Sądowy) is Poland’s national court register number assigned to legal entities. It is a 10-digit sequential registry number.

Offline validation limitation

KRS has no publicly documented checksum algorithm. Numerik validates format and structure only — it cannot verify whether a given KRS number is actually assigned in the registry. For authoritative verification, query the official KRS registry API.

Usage

import { Numerik } from '@slashlab/numerik-js'

// Boolean
Numerik.krs().isValid('0000127206')   // true

// Numbers without leading zeros are accepted and normalised
Numerik.krs().isValid('127206')       // true

// Rich result
const result = Numerik.krs().validate('0000127206')
result.isValid   // true

// Parse to value object
const krs = Numerik.krs().parse('0000127206')

// Null on failure instead of exception
const maybe = Numerik.krs().tryParse('bad-input') // null

Value object API

parse() and tryParse() return a Krs instance.

Core

Method	Return type	Description
getRaw()	string	The original input, untouched.
getNormalized()	string	Raw digits as provided (no extra padding stored).
toString()	string	Alias for getNormalized().

Formatting & metadata

Method	Return type	Description
getFormatted()	string	Zero-padded to 10 digits, e.g. 0000127206.
getNumericValue()	number	Numeric integer value of the KRS number.

Examples

const krs = Numerik.krs().parse('0000127206')

krs.getRaw()           // '0000127206'
krs.getNormalized()    // '0000127206'
krs.getFormatted()     // '0000127206'
krs.getNumericValue()  // 127206

// Short form — leading zeros are not required on input
const krs2 = Numerik.krs().parse('127206')

krs2.getRaw()           // '127206'
krs2.getNormalized()    // '127206'
krs2.getFormatted()     // '0000127206'
krs2.getNumericValue()  // 127206

Failure reasons

Reason	Value	When
InvalidLength	invalid_length	Input is empty, or has more than 10 digits, after normalisation.
InvalidCharacters	invalid_characters	Non-digit characters remain after stripping whitespace.
AllZeros	all_zeros	All digits are zero — numeric value is 0, which is not a valid registry number.
AllSameDigit	all_same_digit	All 10 digits are identical — strict mode only.

Validation algorithm

KRS is a sequential registry number with no checksum. Validation is structural only:

1. Strip spaces. Assert between 1 and 10 digits remain.
2. Assert all remaining characters are digits.
3. Assert the numeric value is not zero.
4. In strict mode, zero-pad to 10 digits and reject inputs where all digits are identical; fail with AllSameDigit.

A number that passes these checks is structurally valid — it conforms to the KRS format. It may or may not correspond to an actually registered entity.