What is a Polish NIP?

The NIP (Numer Identyfikacji Podatkowej) is Poland's 10-digit tax identification number. For VAT purposes it is prefixed with PL, giving a VAT number like PL5260250995.

How is the NIP check digit calculated?

Multiply the first 9 digits by the weights 6,5,7,2,3,4,5,6,7, sum the products, and take the sum modulo 11. That remainder must equal the 10th digit. If the remainder is 10, the NIP is invalid because no such check digit is ever issued.

Does a valid check digit mean the company is VAT-registered?

No. A valid check digit only confirms the NIP is internally consistent. To confirm the business is an active VAT payer, check Poland's official Biała lista (white list) or the EU VIES system.

Do I need to include the PL prefix?

No. The validator accepts the NIP with or without the PL prefix and ignores spaces and dashes, so PL 526-025-09-95 and 5260250995 are treated identically.

Why is my NIP failing?

Almost always a mistyped or transposed digit. The modulo-11 check catches single-digit errors and most transpositions, so re-check each digit against the source document.

Poland VAT Number Validator

A Polish VAT number is the country’s 10-digit tax identifier — the NIP (Numer Identyfikacji Podatkowej) — usually shown with a PL prefix for EU trade, e.g. PL5260250995. Before you record a supplier or file a JPK_V7 return, you can confirm the number is well-formed using the official NIP check-digit rule. This free validator runs that exact modulo-11 check in your browser.

How it works

The NIP uses a weighted modulo-11 check digit:

Strip the optional PL prefix plus any spaces or dashes, leaving 10 digits.
Multiply the first 9 digits by the weights: 6, 5, 7, 2, 3, 4, 5, 6, 7.
Sum the 9 products and take the sum modulo 11.
That remainder must equal the 10th (check) digit. If the remainder works out to 10, the NIP is invalid — such a check digit is never issued.

The tool shows you the weighted sum, the sum mod 11 value, and the expected versus actual check digit so the result is fully transparent.

Example

Validate 5260250995. Apply the weights to the first 9 digits 5 2 6 0 2 5 0 9 9:

(5×6)+(2×5)+(6×7)+(0×2)+(2×3)+(5×4)+(0×5)+(9×6)+(9×7)
= 30+10+42+0+6+20+0+54+63 = 225
225 mod 11 = 5

The 10th digit is 5, which matches — so the check digit is valid.

Notes

A valid check digit means the NIP is structurally correct, which is what JPK_V7 e-reporting and intra-EU VAT documentation require. It does not prove the company is an active VAT payer; for live status, query Poland’s Biała lista or the EU VIES service. Everything here runs locally — your VAT number never leaves your device.