Delayed invoice payment, an overdue loan, or an unpaid court judgment — in all these cases, the creditor is entitled to interest for delay. Polish law distinguishes several types of interest, and their level is directly tied to the NBP reference rate.
Types of Interest Under Polish Law
Polish civil and commercial law distinguishes three main categories:
- Statutory interest (Art. 359 Civil Code): applies as remuneration for the use of another party's capital when the parties have not agreed otherwise. Rate: NBP reference rate + 3.5 pp.
- Statutory interest for delay (Art. 481 Civil Code): owed to the creditor for each day of delay in a monetary obligation. Rate: NBP reference rate + 5.5 pp.
- Late payment interest in commercial transactions (Act of 8 March 2013): applies to B2B relations. Rate: NBP reference rate + 10 pp (or 11 pp when a public entity is the debtor).
NBP Reference Rate in 2026
The NBP reference rate for 2026 is 5.75% (following rate cuts in late 2025/early 2026). This directly affects interest levels:
- Statutory interest: 5.75% + 3.5% = 9.25% per annum
- Statutory interest for delay: 5.75% + 5.5% = 11.25% per annum
- Commercial transaction interest: 5.75% + 10% = 15.75% per annum
How to Calculate Interest — Formula
Interest is calculated using the proportional (simple interest) method:
- Interest = Principal × Annual Rate × Number of Days Overdue / 365
Example: invoice for 15,000 PLN unpaid for 45 days, commercial transaction interest rate (15.75%):
- 15,000 × 0.1575 × 45 / 365 = 292.12 PLN
Interest accrues from the day following the payment due date.
Maximum Interest — Statutory Cap
The Civil Code introduces maximum interest: it cannot exceed twice the statutory interest for delay. In 2026, the maximum rate is therefore 22.50% (2 × 11.25%).
Contractual provisions setting interest above the maximum are null and void — the statutory rate applies.
Compensation for Recovery Costs in B2B Transactions
In B2B commercial relations, the creditor is additionally entitled to a fixed compensation for debt recovery costs:
- 40 EUR — when the debt does not exceed 5,000 PLN
- 70 EUR — when the debt is between 5,001 and 50,000 PLN
- 100 EUR — when the debt exceeds 50,000 PLN
This compensation is owed automatically upon delay — no formal demand is required.
Calculate your interest: Statutory Interest Calculator Poland 2026 →