In a civil lawsuit under Polish law between businesses, the creditor has several ways to prove the existence of their claim. The judgment appears predictable if the creditor possesses an invoice (Polish: faktura VAT ) signed by the opposing party. However, the question arises: what options does a business have if the invoice is not signed by the debtor and, furthermore, no written contract exists?

1) Delivery of an invoice

To prove that the claim documented in the invoice actually arose and is due, the business owner demonstrate in court that the debtor received the invoice. This can be done with proof of sending the invoice by registered mail or email .

Why is this important evidence? It shows that the debtor trusted, or should have trusted, the contents of the invoice, and if they questioned the existence of the claim in any way, they should have done so—logically speaking—immediately after receiving the invoice . Consider this: if you received an invoice for a service or goods you hadn't ordered, what would you do? You would certainly write a letter or email requesting clarification and return the invoice. The debtor should act in the same way if they question the invoice they received in any way.

Furthermore, proof of delivery of an invoice is very important for asserting claims under the law on payment terms in commercial transactions (including interest).

2) Debtor's account books

All business owners are aware that every invoice received should be properly recorded. The debtor should do the same with your invoice. Therefore, it is always worthwhile to include a request in your lawsuit to compel the defendant to produce an extract from their tax records . The debtor's recording of an invoice serves as proof that they have accepted it and that a legal relationship exists from which the disputed claim arises.

3) Partial payment of the invoice

If the debtor has only partially paid the invoice, this constitutes proof that a legal relationship exists between the parties. Therefore, submit the payment confirmation Polish court . Naturally, the details of any verbal agreement between the parties (such as deadlines, scope, etc.) are subject to evidentiary proceedings. However, it is crucial that the debtor can no longer dispute the existence of the claim.

4) History of business contacts

If the unpaid invoice is not the first invoice you have issued to the debtor and all previous invoices have been paid, you should point this out to the court in your lawsuit. This is important because the court, when establishing a legal relationship, will also consider existing contacts and cooperation between the parties. It is also important to note that the debtor paid the previous invoices without dispute.

If you have previously issued invoices to your current debtor without a written contract , and the debtor accepted and paid these invoices without formalizing the ongoing cooperation, this indicates that specific rules of cooperation have developed in your business relationship. According to these rules, you issued a further invoice documenting the completion of a specific service, which the debtor, however, failed to pay.

The history of existing business contacts, as well as the developed rules of cooperation, are very important for assessing the respective facts and determining a legal relationship existing between the parties.

***

Of course, the examples mentioned above are only some of the ways in which the existence of a claim can be proven before Polish courts . Remember that you can also use evidence in the form of witness statements. However, written contracts are the most secure form of proof.

---

For questions regarding claims arising from invoices in Poland, please contact us by email at kontakt@kancelaria-pozniak.pl or by phone at +48 665 246 969 .