What Is a NIP Number?

NIP stands for Numer Identyfikacji Podatkowej, Poland's tax identification number. It's assigned to every business, legal entity, and VAT-registered taxpayer^[1]. If you need a VAT number in Poland, NIP is it.

For EU cross-border transactions, Polish companies prefix their NIP with "PL" to form a VAT ID (e.g., PL5272830422). The European Commission's VIES system validates numbers in this format^[7].

Since September 1, 2011, individuals who don't run a business and aren't VAT-registered use their PESEL as a tax identifier instead^[1]. You only get a NIP if you register a sole proprietorship, form a company, or register for VAT.

NIP Format and Structure

A Polish NIP is exactly 10 digits. No letters, no separators in the raw format. Older documents sometimes show it as XXX-XXX-XX-XX or XXX-XX-XX-XXX, but the underlying number is always 10 consecutive digits.

Digit Breakdown

The first three digits identify the urząd skarbowy (tax office) that originally issued the number. Poland has over 400 tax offices, each with a unique 3-digit code. Warsaw offices carry prefixes in the 525–527 range. This prefix is fixed at registration and never changes, even if the taxpayer relocates.

The next six digits are a sequential identifier. The tenth is a check digit calculated using a mod-11 algorithm.

No official government database publishes a complete mapping of prefix codes to tax offices.

The Mod-11 Check Digit

The check digit catches typos and blocks fabricated numbers. Multiply each of the first nine digits by a fixed weight, sum the products, divide by 11. The remainder must equal the tenth digit.

The weight sequence is: 6, 5, 7, 2, 3, 4, 5, 6, 7.

Take a NIP with first nine digits 123456789:

(1×6) + (2×5) + (3×7) + (4×2) + (5×3) + (6×4) + (7×5) + (8×6) + (9×7) = 6 + 10 + 21 + 8 + 15 + 24 + 35 + 48 + 63 = 230

230 mod 11 = 10. A remainder of 10 means this digit combination is invalid. No NIP can use this sequence because no single digit represents 10.

Try 123-456-78-5 instead:

(1×6) + (2×5) + (3×7) + (4×2) + (5×3) + (6×4) + (7×5) + (8×6) + (5×7) = 6 + 10 + 21 + 8 + 15 + 24 + 35 + 48 + 35 = 202

202 mod 11 = 4. The check digit is 4, making the full NIP 1234567854.

No official Polish government source publishes this algorithm. The weight sequence and mod-11 procedure are common technical knowledge documented across developer resources.

NIP Regex for Developers

For format validation only:

^\d{10}$

This checks length and digit-only content. To verify the check digit, implement the mod-11 algorithm above. For the EU VAT format with country prefix:

^PL\d{10}$

How This Generator Works

The generator creates random 10-digit numbers that pass the mod-11 checksum. Each starts with a valid 3-digit tax office prefix, followed by a random 6-digit sequence. The tool calculates the correct check digit using the weight sequence above. If the remainder is 10, that combination is discarded and a new one is generated.

Use cases: testing Polish invoicing and accounting systems, QA for platforms that validate Polish tax IDs, developer testing for VIES integrations, training environments that need realistic NIP numbers.

Who Needs a NIP?

Businesses and Legal Entities

Every company registered in Poland receives a NIP^[2]. Sole proprietorships (jednoosobowa działalność gospodarcza), sp. z o.o., spółka akcyjna, partnerships, foundations, associations. For sole proprietors, CEIDG assigns the NIP automatically during business registration^[1].

Individuals

Most individuals in Poland don't have a NIP and don't need one. PESEL serves as the tax identifier for anyone not running a business and not VAT-registered^[1]. You need a NIP only if you register a business, become a VAT taxpayer, or act as a tax collector (an employer withholding income tax, for instance).

Foreigners and Foreign Companies

Same rules apply. Run a business and you get a NIP through CEIDG or KRS registration. Need a NIP for VAT purposes without a business? File the NIP-7 form at your local tax office^[3].

Foreign companies without a physical presence in Poland can also receive a Polish NIP if they have tax obligations here, like VAT registration for selling goods or services to Polish customers.

How to Get a NIP

Sole proprietors register through CEIDG (Centralna Ewidencja i Informacja o Działalności Gospodarczej). CEIDG assigns the NIP during business registration^[1].

Companies and legal entities register through KRS (Krajowy Rejestr Sądowy). The court forwards your data to the tax office, which assigns the NIP^[2].

Individuals who need a NIP outside business registration submit the NIP-7 form to their local tax office^[3]. The tax office issues the number within 3 business days of receiving a correct application^[4].

NIP registration is free. Getting a certificate confirming your NIP assignment is also free^[4].

NIP vs. REGON vs. KRS

Poland uses three separate identification numbers for businesses. They're independent. Knowing one doesn't let you derive the others.

NIP identifies the taxpayer for tax and VAT purposes. It goes on invoices, tax returns, and contracts.

REGON (Rejestr Gospodarki Narodowej) is a statistical number assigned by GUS, the Central Statistical Office. Every business entity and its local branches receive one.

KRS (Krajowy Rejestr Sądowy) is a court registry number. Companies, foundations, and associations registered with the National Court Register receive a KRS number. Sole proprietors registered through CEIDG don't have one.

If you need to generate test REGON numbers, the REGON Generator tool works the same way as this NIP generator.

Verifying an Existing NIP

This page generates fictitious NIP numbers for testing. To check whether a real NIP belongs to an active taxpayer, use the NIP Validator tool.

The Ministry of Finance runs an online VAT status checker that confirms whether a NIP is registered as an active VAT taxpayer^[5]. The biała lista (white list) lets you verify a company's NIP, registered name, address, and bank account numbers^[6]. Businesses use it to confirm contractor details before making payments over 15,000 PLN.

For EU cross-border verification, the VIES system validates Polish VAT numbers in the PL + 10-digit format^[7].

Common Questions

Can I use generated NIP numbers for real transactions?

No. Using a fabricated NIP on official documents or invoices is illegal.

Does the PL prefix count as part of the NIP?

No. "PL" is added only for EU VAT identification. The NIP itself is always 10 digits. VIES expects the prefix; Polish domestic systems don't.

I'm employed in Poland but don't run a business. Do I need a NIP?

No. Your employer files tax declarations using your PESEL, not a NIP^[1].

References

1. Act on the Principles of Registration and Identification of Taxpayers and Tax Collectors (Consolidated Text, 2025) — isap.sejm.gov.pl
2. What is NIP? — Government Business Portal — biznes.gov.pl
3. NIP-7 Registration Form — Government Business Portal — biznes.gov.pl
4. NIP Certificate — Government Business Portal — biznes.gov.pl
5. VAT Status Check — Ministry of Finance Tax Portal — ppuslugi.mf.gov.pl
6. VAT Taxpayer Registry (White List) — Ministry of Finance — podatki.gov.pl
7. VIES — EU VAT Number Validation System — European Commission — ec.europa.eu