Calculate late payment interest on one invoice or a dozen at once. The calculator adds the compensation for recovery costs and prepares an interest note you can print.
The calculator helps you prepare the amounts for an interest note or a payment demand. It is not legal advice, so check a disputed case with a lawyer.
From 1 July to 31 December 2026, statutory interest for late payment in commercial transactions in Poland is 13.75% a year. It is the National Bank of Poland reference rate on 1 July, which is 3.75%, plus 10 percentage points. In the first half of 2026 the rate was 14%.
When the debtor is a public healthcare provider, 8 percentage points are added to the reference rate instead. In the second half of 2026 that gives 11.75%.
The rate changes twice a year. The first half of the year uses the reference rate in force on 1 January and the second half uses the rate in force on 1 July, even if the Monetary Policy Council changes rates in between. The minister announces the rate in Monitor Polski, the official gazette.
The rates in the table also apply to contracts concluded before 2020, because interest and compensation that fell due after 1 January 2020 follow the new rules (Article 20(3) and (4) of the Act of 19 July 2019 amending certain acts to reduce payment gridlocks). For days of delay up to the end of 2019, the reference rate plus 8 percentage points applies, and if the payment deadline passed before 2020, the compensation is 40 euro. The calculator handles this automatically.
Current reference rates are published by the National Bank of Poland.
Interest runs from the day after the due date until the day the money reaches your account, and the day of payment counts as a day of delay. The base is the gross amount, which is the full amount the customer was supposed to pay.
When the delay spans two half years with different rates, you split the period and calculate each part separately. The calculator does this for you and shows every part in the calculation details.
If the due date falls on a Saturday or a public holiday, it moves to the next business day under article 115 of the Polish Civil Code. The calculator applies this by default, and you can switch it off.
An invoice for PLN 12,300 was due on 15 May 2026 and the customer paid on 30 June 2026. The delay lasted 46 days and the rate in the first half of 2026 was 14%.
The compensation is 70 euro because the invoice is above PLN 5,000. The rate is the NBP average rate from 30 April 2026, the last business day before the month in which payment was due.
When a business customer pays late, you can add a fixed compensation for recovery costs on top of interest. You are entitled to it from the day interest starts to accrue, without sending a demand and without proving any costs. This follows from article 10 of the Polish act on counteracting excessive delays in commercial transactions.
You convert the euro amount into zloty at the NBP average rate from the last business day of the month before the month in which payment was due. The compensation is due for each transaction, which usually means each invoice paid late, even if the delay was one day.
If your recovery costs were higher, for example because of legal fees, you can claim the difference in a reasonable amount. The compensation does not apply to invoices issued to consumers.
An interest note is a document that tells the customer how much late payment interest has accrued and asks them to pay it. It is not a VAT invoice, because interest and the compensation are outside the scope of VAT.
The calculator fills in the note with your results. Click Download interest note, add the company details and save the document as a PDF from the print window.
If the customer still does not pay, the next step is a formal payment demand. For the earlier steps, use our payment reminder email templates.
When a debt does not come from a commercial transaction, for example when the debtor is a consumer, statutory late payment interest under article 481 of the Polish Civil Code applies. Since 5 March 2026 it has been 9.25% a year, which is the NBP reference rate plus 5.5 percentage points.
This rate changes every time the reference rate changes, not every six months. In the calculator, choose the statutory late interest option. The compensation for recovery costs does not apply in this case.
How to calculate interest, when the compensation applies and what to put in an interest note.
It was 14% a year from 1 January to 30 June 2026 and is 13.75% a year from 1 July to 31 December 2026. When the debtor is a public healthcare provider, the rates are 2 percentage points lower, at 12% and 11.75%.
From the day after the due date until the day of payment, inclusive. The day of payment is the day the money reaches the creditor’s account. If the due date falls on a Saturday or a public holiday, it moves to the next business day.
On the gross amount, which is the full amount the customer was supposed to pay. If the customer paid part of it, you calculate interest on the full amount until the partial payment and on the remaining balance after that.
Yes. The compensation applies to each commercial transaction, so with several late invoices you calculate it separately for each one. It is 40, 70 or 100 euro depending on the invoice amount.
The NBP average euro rate from the last business day of the month before the month in which payment was due. For an invoice due on 15 May 2026, that is the rate from 30 April 2026. The calculator fetches it from NBP automatically.
No. Interest in commercial transactions and the compensation are due without a demand, simply because the payment is late. An interest note and a payment demand still help you get paid, because the customer receives a specific amount and deadline.
Yes. Sunbay calculates interest for every overdue invoice and sends interest notes automatically at the step of the path you choose for each customer group. Interest notes and payment demands are included in the Standard and Pro plans.
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