How to verify a contractor
before a transaction
Before you pay an invoice or sign a contract, it takes a few minutes to check that a Polish company exists, is registered for VAT and gives a bank account reported to the tax authorities. Below is a 6-step due-diligence checklist — each step links to a free tool where you complete it by tax ID (NIP), with no sign-up.
Why verify a contractor
"Due diligence" (należyta staranność) is the set of checks that show you vetted a business partner before a transaction. It has real tax consequences: for payments above PLN 15,000, paying into an account outside the VAT White List risks joint liability for the contractor's VAT and the loss of the right to book the expense as a tax-deductible cost. Verification also protects you from dealing with an entity that does not exist, has been struck off the register or is not entitled to issue VAT invoices.
The checklist in 6 steps
1. VAT status — VAT White List
Check whether the contractor is an active VAT payer. Enter the NIP in the VAT White List tool to see the status (active / exempt / not registered), the registration date and the bank accounts reported to the register — straight from the Ministry of Finance.
2. Bank account — is it on the White List
Compare the account number on the invoice with the White List accounts in the Bank account check tool. A payment above PLN 15,000 into an account outside the register is a tax risk — if it has already happened, a ZAW-NR notification filed within 7 days protects you.
3. Registration data — KRS or REGON
Companies, foundations and associations are in the National Court Register (KRS): representation, capital, status. Sole traders (JDG), who are not in the KRS, are verified by NIP in the REGON register (Statistics Poland) — official name, address and legal form.
4. EU contractor — EU VAT in VIES
If you issue a zero-VAT invoice to a company in another EU country, confirm its EU VAT number in VIES (European Commission). An active EU VAT number is a condition for applying the 0% rate to an intra-Community supply of goods.
5. Business activity — PKD codes
The PKD codes show what a company officially does. If the subject of the transaction does not match the declared activity at all, that is a reason for caution.
6. Beneficial owner — CRBR
Who really controls a company can be established in the Central Register of Beneficial Owners (crbr.podatki.gov.pl). It is a free, public search run by the Ministry of Finance — useful especially for larger contracts and checking connections.
Checking a whole portfolio of contractors at once? Instead of entering NIPs one by one, use the Bulk NIP tool: paste a list, get a table with the VAT status, accounts, REGON and KRS of each entity plus CSV or JSON export.
When verification matters most
- Payments above PLN 15,000 — the threshold from which the White List account and the split-payment mechanism (MPP) matter.
- VAT deduction and tax-deductible costs — the tax office may challenge them if you did not exercise due diligence.
- A new contractor or a large contract — the first transaction with an unknown entity is a natural moment for a full check.
- Intra-EU transactions — without an active EU VAT number in VIES you cannot apply the 0% rate.
Frequently asked questions
What is due diligence (należyta staranność)?
It is the set of checks on a contractor before a transaction — including VAT status, bank account and registration data. Exercising due diligence lets you keep the right to deduct VAT and book the expense as a cost if the contractor turns out to be dishonest.
How do I check a company using only its tax ID (NIP)?
The NIP alone is enough to check VAT status in the VAT White List, data in the REGON register and — for companies — the link to a KRS entry. You complete all of these steps in the free skanfirmy.pl tools with no sign-up.
Which steps are mandatory?
No single step is explicitly required, but for payments above PLN 15,000 checking the VAT status and the account in the White List is the only way to avoid joint liability for the contractor's VAT and keep the right to book the expense as a cost.
How do I verify a company from another EU country?
You confirm the EU VAT number of a contractor from another member state in the European Commission's VIES system. An active number is a condition for applying the 0% rate to an intra-Community supply of goods.
Is verifying a contractor free?
Yes. You complete every step of this checklist free of charge and without registration — the data comes straight from official state registers (Ministry of Finance, KRS, Statistics Poland, European Commission).