Late payment interest calculator

Work out the interest and compensation the law lets you claim on a late invoice, and get a claim letter ready to send.

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Usually your own country, as the supplier, unless the contract chooses another law.

A guide, not legal advice: check your contract's payment terms first.

Liechtenstein: how late payment interest is calculated

Law
General Commercial Code, articles 336a to 336e (Allgemeines deutsches Handelsgesetzbuch (ADHGB), Art. 336a–336e)
Statutory interest
Swiss National Bank special rate (Sondersatz der Schweizerischen Nationalbank) + 8 percentage points
8.25% from 1 July 2026 to 31 December 2026
Fixed compensation
CHF60 for each late invoice

When the rate changes, each period's rate applies to the days in that period, also on an invoice that was already late.

Interest runs from the day after the due date up to and including the day of payment. The year counts as 365 days. The law does not set the day count: this is the one the calculator uses.

Interest = amount unpaid × rate × days late ÷ 365

If recovering the debt costs more, the reasonable difference can be claimed as well.

Example

An invoice of CHF5,000 due on 1 August 2026 and paid on 30 September 2026 is 60 days late. The interest comes to CHF67.81 and the fixed compensation to CHF60: CHF127.81 in all.

Statutory interest rates

Checked on 26 October 2026 against the official sources below.

Period Reference rate Statutory rate
01/07/2026 – 31/12/2026 0.25% 8.25%
01/01/2026 – 30/06/2026 0.50% 8.50%
01/07/2025 – 31/12/2025 0.50% 8.50%
01/01/2025 – 30/06/2025 1.00% 9.00%
01/07/2024 – 31/12/2024 1.75% 9.75%
01/01/2024 – 30/06/2024 2.25% 10.25%
01/07/2023 – 31/12/2023 2.25% 10.25%
01/01/2023 – 30/06/2023 1.50% 9.50%
01/07/2022 – 31/12/2022 0.25% 8.00%
01/01/2022 – 30/06/2022 0.00% 8.00%
01/07/2021 – 31/12/2021 0.00% 8.00%
01/01/2021 – 30/06/2021 0.00% 8.00%
01/07/2020 – 31/12/2020 0.00% 8.00%
01/01/2020 – 30/06/2020 0.50% 8.50%

Sources

Questions and answers

Which country's law applies to a late payment?

The law that governs the contract. Most contracts choose it; when yours does not, a contract for services is usually governed by the law of the supplier's country, under the EU's Rome I Regulation and similar rules elsewhere. Choose that country in the calculator.

Do I need a clause in my contract to charge interest?

Not in the European Union, the United Kingdom and many other countries: the law adds interest, and usually a fixed sum of compensation, to every late invoice between businesses. In others, such as the United States, Canada and Australia, there is no statutory rate for business invoices: you charge the rate your contract sets, and without one only a court can award interest. The calculator then asks for your contract's rate.

Is the compensation owed for each invoice?

Yes, where the law sets one. Under the EU Late Payment Directive and the UK Late Payment Act, the fixed sum is owed for each late invoice on top of the interest, and reasonable recovery costs above it can usually be claimed too. The calculator adds the amount the chosen country sets.

Which rate applies if the rate changes while the invoice is unpaid?

It depends on the country. Most of the EU applies each half-year's rate to the days in that half-year, while the UK keeps the rate in force when interest started until the debt is paid. The calculator follows the rule of the country you choose and shows the rates it used.

What if the rate for the current period is not in the calculator yet?

The rates are updated when central banks and governments publish them, usually for 1 January and 1 July. Until a new rate is in, the calculator says so rather than work with an old one.

Does anything I type leave my browser?

No. The calculation and the letter are made in your browser. When you change country, the page only downloads that country's rules; your amounts, dates and names are never sent.

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