Late payment interest calculator for commercial transactions in Poland 2026, with 40, 70 and 100 EUR compensation

How we calculate

1. 1. From when to when

   Interest runs without a demand from the day the payment is due until it is paid, if you performed your side and the customer did not pay by the contract deadline (art. 7 ust. 1 and art. 8 ust. 1 of the Act on counteracting excessive delays in commercial transactions). We count it from the day after the deadline up to and including the payment date. A deadline on a Saturday or a statutory day off moves to the next working day (art. 115 of the Civil Code).

2. 2. The rate in each half-year

   Statutory interest for delay in commercial transactions is the NBP reference rate plus 10 percentage points, or plus 8 points when the debtor is a public entity that is a healthcare provider (art. 4 pkt 3). The reference rate of 1 January applies to the first half-year and that of 1 July to the second (art. 11b). From 1 July to 31 December 2026 the rate is 13.75%, and 11.75% for healthcare providers (M.P. 2026 poz. 642).

3. 3. Formula

   For each half-year: amount × days × rate / 365. We round the total to the grosz. The parties may agree on higher interest (art. 7 ust. 1); the calculator then shows the statutory minimum.

4. 4. Compensation of 40, 70 or 100 EUR

   From the day you become entitled to interest, you are owed compensation for recovery costs without a demand: 40 EUR for an amount up to 5,000 zł, 70 EUR above 5,000 zł and below 50,000 zł, and 100 EUR from 50,000 zł (art. 10 ust. 1). The euro amount is converted at the NBP average rate of the last working day of the month before the month in which the payment fell due (art. 10 ust. 1a).

What the calculator does not cover

• It handles one amount and one payment date. With an instalment schedule, interest and compensation apply to each unpaid part separately (art. 11 ust. 2), so calculate each instalment on its own.
• It does not check whether the contract deadline is allowed. If it exceeds 60 days from delivery of the invoice without the parties' express agreement, or at all when a large company pays a micro, small or medium business (art. 7 ust. 2 and 2a), interest may start earlier, after 60 days (art. 7 ust. 3).
• It does not cover consumer contracts. The Act applies to deals between businesses, public entities and members of liberal professions (art. 2).
• It does not add recovery costs above the compensation (art. 10 ust. 2) or court costs.
• Rates cover the period from 1 January 2020. For days after 31 December 2026 we use the last announced rate.