Work out the interest and compensation the law lets you claim on a late invoice, and get a claim letter ready to send.
| Invoice | Days late | Rate | Interest | Compensation |
|---|
Fill in the names and the letter is ready to print or send.
No federal law adds interest to a late invoice between businesses: you can charge interest if your contract or invoice terms set a rate, within the limits of your state's law. Without an agreed rate, state law decides. For example, Texas allows 6% a year from the 30th day after the due date, California applies 10% a year after a breach of a contract that sets no rate, and New York courts add 9% a year from the date of the breach.
Enter the rate in your contract above: the calculator applies it from the day after the due date up to and including the day of payment.
Interest = amount unpaid × contract rate × days late ÷ 365
Checked on October 26, 2026 against the official sources below.
Late payment: claim for interest under our contract
Dear ,
The invoice below was not paid by its due date.The invoices below were not paid by their due dates.
Under our contract, interest is due on the late amount at a year.
| Interest | |
| Compensation | |
| Invoice amount still unpaid | |
| Total due |
Please pay the total within 14 days of the date of this letter.
Interest continues to run on the unpaid amount at a day until it is paid.
Yours sincerely,
Interest calculated with the free late payment calculator at gocons.eu
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.
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.
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.
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.
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.
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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