- Business in Poland -
Customer Won’t Pay: How to Recover an Unpaid Invoice Fast (From Demand Letter to Lawsuit)
The “customer won’t pay” problem describes a situation where, after you perform the contract and issue an invoice (or once the payment due date set in the contract arrives), the creditor does not receive payment on time even though the debt is already due and payable. In practice, the key is to act quickly: organize your documents, calculate the claim (principal, interest, costs), and choose the best route—settlement with the debtor, firm pre-litigation debt collection, or court debt recovery.
Customer won’t pay: what to do first in your business
The sooner you build a well-organized “evidence pack,” the easier it is to move to effective action. In B2B cases, courts mainly assess documentation and the consistency of the parties’ communications.
- Verify the basis of the claim—contract, purchase order, terms and conditions, acceptance/hand-over protocols, delivery notes, email correspondence.
- Check when the invoice became due—from the invoice, contract, or applicable rules (if the due date was not clearly agreed).
- Send a payment demand letter—short and specific, with a deadline and bank account number; it is also worth citing the legal basis for interest.
- Verify the debtor’s status—KRS/CEIDG registers, any restructuring or insolvency proceedings, changes in management.
Debtor won’t pay the invoice: what a payment demand letter should include
A payment demand letter is not always a formal prerequisite to filing a claim, but in practice it often determines whether you recover money faster and/or strengthens your position in court. A well-prepared demand also makes it easier to prove that the debtor was in default.
Minimum elements:
- the parties’ details and the invoice/contract number,
- the principal amount and the due date,
- interest calculation (or a note from what date interest will accrue),
- a payment deadline (e.g., 7 days in B2B—depending on the relationship and amount),
- bank account number,
- notice that the matter will be referred to court and that the debtor will be charged with costs.
Statutory interest for late payment: how to calculate it
As a rule, the creditor may claim interest for the period of delay even without proving damage (Article 481 of the Polish Civil Code) [1]. In business-to-business dealings, statutory interest for late payment in commercial transactions and a fixed compensation for debt recovery costs may also apply (Act on Counteracting Excessive Delays in Commercial Transactions) [2]. The interest rate and calculation rules depend on the type of transaction and the parties’ status, so the calculation should reflect the specific facts of the case.
Settlement with the debtor: when it speeds things up—and when it backfires
A settlement agreement can be the fastest way to recover funds, but only if it is properly secured. The key is to avoid “soft” arrangements without consequences and without evidence.
Practical protections in a settlement:
- an acknowledgment of debt (generally strengthens the evidentiary position and interrupts the limitation period if it constitutes acknowledgment of the claim within the meaning of Article 123 § 1 point 2 of the Civil Code) [1],
- a repayment schedule with clearly defined dates,
- an acceleration clause making the full amount immediately due in case of delay,
- security (e.g., promissory note, guarantee/surety, voluntary submission to enforcement under Article 777 of the Polish Code of Civil Procedure—where realistically enforceable) [3].
Court debt recovery: how to start and prepare for a lawsuit
If amicable actions do not work, it is worth moving to litigation without delay. In payment claims, speed matters: the longer you wait, the greater the risk of issues with the debtor’s assets or the need to compete with other creditors.
In a typical B2B case you should prepare:
- the contract/arrangements and proof of performance,
- invoices and proof of delivery/receipt or acceptance,
- correspondence about delivery, quality, complaints/claims,
- payment demand letters and proof of sending,
- calculation of the claim (principal, interest, compensation—if applicable).
Lawsuit for payment: when to file and under which procedure
A lawsuit for payment is filed when the claim is due and can be proven with evidence. Depending on the documents and circumstances, the case may qualify for a payment order procedure or a writ-of-payment (order for payment) procedure under the Polish Code of Civil Procedure [3]. Choosing the right route matters for how quickly you can obtain a title that secures the creditor’s interests.
B2B invoice limitation period: the risk of losing the right to pursue the claim
A limitation period means that after a certain time the debtor may effectively raise a limitation defense, which in practice often blocks a win in court. Limitation periods depend on the type of claim, its legal basis, and whether it is connected with business activity (Polish Civil Code) [1]. Assessing a “B2B invoice limitation period” therefore requires checking what agreement the debt arises from (sale, services, construction works), when the claim became due, and whether any events occurred that interrupted or suspended the running of the limitation period.
How to recover a debt from a company: key elements of a dispute strategy
In practice, fast debt recovery is not just about filing a claim. What matters is parallel risk management and selecting tools tailored to the debtor’s situation.
- Diagnose the dispute—is the debtor challenging performance, price, deadlines, quality, or simply not paying?
- Assess solvency—are there assets and a realistic chance of enforcement?
- Choose the litigation path—payment order, writ-of-payment, ordinary proceedings; where needed, consider interim security for the claim.
- Keep communications consistent—reduce email chaos; one position and one channel of contact.
Where a dispute escalates into multi-thread claims and defenses, litigation experience in commercial disputes and the ability to quickly secure evidence can be decisive.
If the situation requires a rapid review of documents, interest calculation, and selection of the correct procedure, a sensible step is to commission a legal analysis by the KKZ team via https://kkz.com.pl/.
FAQ: customer won’t pay—how to recover an unpaid invoice fast
1) Customer won’t pay: what should you do in the first 48 hours?
Gather documents (contract, proof of performance, invoice), confirm the due date, send a short payment demand letter, and in parallel verify the debtor’s status in KRS/CEIDG as well as any restructuring/insolvency proceedings.
2) The debtor won’t pay the invoice but claims they “never received it”—what then?
Secure proof of delivery (email with confirmation, EDI, posting confirmation) or show that the parties agreed payment independently of the invoice (e.g., acceptance protocol, correspondence). The contract wording and the established course of dealings matter.
3) How to calculate statutory interest for late payment in B2B?
The basis is Article 481 of the Civil Code [1], and in commercial transactions often the Act on Counteracting Excessive Delays in Commercial Transactions [2]. The rate and start date depend on the type of transaction and the due date.
4) Settlement with the debtor—when does it make sense?
When the debtor has real ability to pay but needs the payment spread over time. The settlement should include an acknowledgment of debt, a schedule, penalties for delay, and possible security.
5) Court debt recovery: how to start without wasting time?
Prepare a full set of evidence, calculate the claim (principal, interest, and any fixed compensation), then select the appropriate procedure (e.g., payment order procedure) under the Polish Code of Civil Procedure [3].
6) When is the fastest time to file a lawsuit for payment?
When the claim is due and the creditor has documents confirming both the debt and performance. Delays increase evidentiary and enforcement risks.
7) B2B invoice limitation period—how to check the deadline?
Determine the legal basis of the claim, the due date, and assess whether the limitation period has been interrupted or suspended. Time limits follow the Civil Code, but in practice they depend on the type of contract and circumstances [1].
Bibliography
- [1] Act of 23 April 1964 — Polish Civil Code (consolidated text: Journal of Laws 2024, item 1061, as amended).
- [2] Act of 8 March 2013 on Counteracting Excessive Delays in Commercial Transactions (consolidated text: Journal of Laws 2023, item 1790, as amended).
- [3] Act of 17 November 1964 — Polish Code of Civil Procedure (consolidated text: Journal of Laws 2024, item 1568, as amended).
Author: adv. Maciej Zaborowski, Managing Partner
E-mail: m.zaborowski@kkz.com.pl
