Calculator
Polish tax-arrears interest calculator
Calculate interest on one Polish tax arrear across rate changes. The model applies the PLN 8.70 non-accrual threshold and rounds the settlement to whole PLN. Reduced and enhanced rates require independent confirmation of statutory eligibility.
Calculator
Enter data
Payment from 1 January to 22 September 2026; accrual from 1 January 2025. Fields marked with an asterisk are required.
How to use the calculator
- Enter the effective due date after any applicable weekend/holiday adjustment. Accrual starts the following day and includes payment day.
- Automatic mode splits periods on rate changes. Manual mode assumes one constant rate; calculate separate intervals if it changes. Do not confuse maximum and statutory rates.
Calculation details
Formula and calculation method
Sum of principal × annual percentage rate × days / 36500; actual days with a fixed 365 denominator. Period amounts are not rounded before summing. Civil result to cents; tax result to whole PLN after testing the unrounded total against PLN 8.70.
Worked example
PLN 10,000 arrears, due 4 March 2026, paid 14 March: 10 days × 10.5% / 365 × PLN 10,000 = PLN 28.767…; standard interest payable is PLN 29.
Limitations
- Payment from 1 January to 22 September 2026; accrual from 1 January 2025.
- One unchanged debt, without partial payments, compounding, collection charges, accrual suspensions or limitation-period assessment. Selecting a mode does not establish legal entitlement.
- 50% requires a legally effective correction within six months of the filing deadline and payment within seven days, subject to exclusions including audits and verification activities. 150% applies only to specified VAT/excise cases under Article 56b, not every delay. This calculator does not decide these conditions or other Article 54 exemptions.
Sources
Frequently asked questions
What does this tool cover?
Calculate interest on one Polish tax arrear across rate changes. The model applies the PLN 8.70 non-accrual threshold and rounds the settlement to whole PLN. Reduced and enhanced rates require independent confirmation of statutory eligibility.
Which assumptions should I verify?
Payment from 1 January to 22 September 2026; accrual from 1 January 2025. One unchanged debt, without partial payments, compounding, collection charges, accrual suspensions or limitation-period assessment. Selecting a mode does not establish legal entitlement. 50% requires a legally effective correction within six months of the filing deadline and payment within seven days, subject to exclusions including audits and verification activities. 150% applies only to specified VAT/excise cases under Article 56b, not every delay. This calculator does not decide these conditions or other Article 54 exemptions.
Are entered values stored?
Calculations run locally in your browser. Entered identifiers, amounts and results are not stored or sent to analytics.