Late Payment Interest Calculator (D.Lgs. 231/2002)
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Late Payment Interest Calculator
Default interest on invoices paid late between businesses and to the public administration (D.Lgs. 231/2002), half-year by half-year with the rates published by the MEF (Ministry of Economy and Finance)
Rates loaded from the 1st half of 2013 to the 2nd half of 2026: the table is updated in January and July, when the Ministry of Economy publishes the new reference rate in the Gazzetta Ufficiale (Official Journal). The calculation applies to commercial transactions concluded from 1 January 2013 between businesses or between businesses and public administrations; it does not apply to debts owed by consumers, for which statutory interest is used. It is an informational estimate: for a formal demand letter, a payment order (decreto ingiuntivo) or a contract with special clauses, consult a lawyer or your accountant.
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How the late payment interest calculation works
When a business or a public administration pays an invoice late, the supplier is entitled to the late payment interest under D.Lgs. 231/2002, the law on late payment in commercial transactions. The calculator works it out from three inputs: amount due, due date and payment date (or today, if the invoice is still unpaid), and shows the total to claim with a breakdown for each half-year covered by the delay.
The calculation runs in your browser, without sending any data. It applies to contracts between businesses and between businesses and public administrations concluded from 1 January 2013. If the debtor is a consumer, the statutory interest under the Civil Code applies instead: use the statutory interest calculator.
The rate: ECB rate plus 8 points, half-year by half-year
The law defines statutory late payment interest as simple interest calculated on a daily basis, at a rate equal to the reference rate plus 8 percentage points (art. 2 of D.Lgs. 231/2002). The reference rate is the one applied by the European Central Bank to its most recent main refinancing operations: for the first half of the year the rate in force on 1 January applies, for the second half the rate in force on 1 July (art. 5). The Ministry of Economy publishes it every six months in the Gazzetta Ufficiale.
The rules applied:
- Automatic accrual: interest runs from the day after the due date, with no need for a formal notice of default (art. 4). Days are counted up to and including the payment date.
- One rate per half-year: each day of delay takes the rate of the half-year it falls in, without compounding.
- Formula: amount × rate × days ÷ 365. The law does not set the divisor: here 365 is used even in leap years, the most common convention, but 29 February counts as a day of delay.
- Flat-rate compensation: the creditor is also entitled to €40 for recovery costs, without a notice of default and without prejudice to proof of greater damage (art. 6). The option can be removed.
- Agricultural and food products: if the sale does not respect the payment terms of D.Lgs. 198/2021, the rate is increased by a further 4 points and cannot be waived (art. 4, paragraph 2). It applies to contracts concluded from 15 December 2021.
Rate table from 2013 to 2026
Each rate comes from the Ministry of Economy's notice in the Gazzetta Ufficiale, checked against the ECB historical data. The latest half-year loaded is the second half of 2026 and the table is updated in January and July: for a half-year not yet published, the calculator flags it without estimating the rate.
| Half-year | Reference rate | Late payment rate |
|---|---|---|
| 1st half 2013 | 0.75% | 8.75% |
| 2nd half 2013 | 0.50% | 8.50% |
| 1st half 2014 | 0.25% | 8.25% |
| 2nd half 2014 | 0.15% | 8.15% |
| 1st half 2015 | 0.05% | 8.05% |
| 2nd half 2015 | 0.05% | 8.05% |
| 1st half 2016 | 0.05% | 8.05% |
| from the 2nd half 2016 to the 2nd half 2022 | 0.00% | 8.00% |
| 1st half 2023 | 2.50% | 10.50% |
| 2nd half 2023 | 4.00% | 12.00% |
| 1st half 2024 | 4.50% | 12.50% |
| 2nd half 2024 | 4.25% | 12.25% |
| 1st half 2025 | 3.15% | 11.15% |
| 2nd half 2025 | 2.15% | 10.15% |
| 1st half 2026 | 2.15% | 10.15% |
| 2nd half 2026 | 2.40% | 10.40% |
Calculation example
An invoice for €7,320 (VAT included: by law the amount due includes the taxes shown on the invoice) is due on 30 November 2025 and is paid on 20 July 2026. The delay is 232 days across three half-years. The figures produced by the calculator:
| Period | Days | Rate | Interest |
|---|---|---|---|
| from 01/12/2025 to 31/12/2025 | 31 | 10.15% | €63.10 |
| from 01/01/2026 to 30/06/2026 | 181 | 10.15% | €368.44 |
| from 01/07/2026 to 20/07/2026 | 20 | 10.40% | €41.71 |
| Late payment interest | 232 | €473.25 | |
| Flat-rate compensation | €40.00 | ||
| Total to claim | €7,833.25 |
For the first segment: 7,320 × 10.15% × 31 ÷ 365 = €63.10. Each row is rounded to the cent and the total is the sum of the rows, so the calculation can be redone by hand.
When it applies and when it does not
The law covers payments for goods or services between businesses, including professionals, or to a public administration. Excluded are debts subject to insolvency proceedings and payments made as compensation for damages (art. 1). Between businesses a different rate may be agreed, within the limits of art. 7: in that case that rate applies, which the calculator does not handle.
For transactions concluded before 2013 the original version applied, with a 7-point increase instead of 8: the calculator does not handle it and flags due dates before 1 January 2013. Nor does it handle partial payments: in that case, calculate one period at a time. It is an informational tool: for a formal demand letter or a payment order, the point of reference remains a lawyer or an accountant.
Frequently asked questions
How is late payment interest calculated?
Multiply the amount due by the late payment rate and by the days of delay, then divide by 365. The rate is the ECB reference rate plus 8 points and changes every half-year: if the delay spans more than one, do a calculation for each half-year with its own rate and add up the results. The interest is simple, not compounded.
What is the late payment interest rate in the second half of 2026?
For the period from 1 July to 31 December 2026 the reference rate announced by the Ministry of Economy is 2.40% (Gazzetta Ufficiale no. 163 of 16 July 2026): with the 8-point increase the late payment rate is 10.40%. In the first half of 2026 it was 10.15%. For sales of agricultural and food products paid after the legal deadlines, a further 4 points are added.
Do you need a formal demand letter to claim late payment interest?
No. In commercial transactions late payment interest accrues automatically from the day after the due date, with no need for a formal notice of default (art. 4 of D.Lgs. 231/2002). The same applies to the €40 flat-rate compensation for recovery costs (art. 6).
What is the difference between late payment interest and statutory interest?
Statutory interest is the interest under art. 1284 of the Civil Code, with a rate set every year by decree of the Ministry of Economy, and it also applies to consumers. Late payment interest under D.Lgs. 231/2002 applies only to delays in commercial transactions between businesses or with the public administration, with the ECB rate plus 8 points updated every half-year.
Related tools: the statutory interest calculator for debts owed by consumers, the days calculator to count the days between two dates and the VAT calculator for the invoice VAT.
