Late Payment Interest Calculator: what an overdue invoice now costs
Enter the amount and the due date to see the interest and fees your client owes. Use the rate in your terms, a flat fee, or statutory interest under late payment law.
How to work out late payment interest
- 1
Enter the overdue amount
Use the amount still unpaid on the invoice, and choose its currency.
- 2
Add the dates
Enter the due date on the invoice and the date it was paid, or today if it is still unpaid.
- 3
Choose how you charge
Pick the rate in your terms, a flat late fee, or statutory interest for business-to-business invoices in your country.
- 4
Copy the result
See the interest, any fixed compensation and the total owed. Copy wording for your invoice terms, so your next client knows up front.
Statutory late payment interest, October 2026
In some countries a business that pays another business late owes interest set by law, even if your terms say nothing about it. The rates below apply to business-to-business invoices that went late in the second half of 2026.
CountryRate a yearHow it is setFixed compensation
United Kingdom
11.75%
Bank of England base rate (3.75%) + 8 points
£40, £70 or £100 by invoice size
Ireland
10.40%
ECB rate (2.40%) + 8 points
€40, €70 or €100 by invoice size
Germany
10.52%
Basiszinssatz (1.52%) + 9 points
€40
France
12.40%
ECB rate + 10 points, if your terms set no rate
€40
Netherlands
10.40%
ECB rate + 8 points
At least €40
Spain
10.40%
ECB rate + 8 points
€40
Other EU (euro)
At least 10.40%
ECB rate + at least 8 points
At least €40
India (MSE suppliers)
17.25%
3 × RBI bank rate (5.75%), compounded monthly
None
The reference rate is fixed twice a year: on 30 June or 1 July for interest from July to December, and on 31 December or 1 January for January to June. The ECB raised its rate to 2.65% in September 2026, so the EU rates are expected to rise to 10.65% from January 2027.
The United States, Canada, Australia, New Zealand and Singapore have no general statutory interest on late business invoices. You can charge only what your contract or invoice terms say, within any state or provincial limits. In Canada, a rate per month is only enforceable above 5% a year if your terms also give the yearly rate.
How to avoid late payments
- Agree terms before you start. Put your payment terms and late fee in the quote or contract, and repeat them on every invoice.
- Invoice promptly, with a clear due date and all the details your client needs to pay.
- Make paying easy: bank details, a payment link and the invoice number to use as the reference.
- Follow up early. A friendly reminder a few days before and on the due date gets most invoices paid.
- Ask for a deposit on large jobs, or stage payments as the work goes.
Create invoices with your terms already on them using the invoice generator, or send and track invoices in BunnyDoc Invoicing. This page is general information, not legal advice.
Late payment calculator FAQs
How do I calculate interest on a late payment?
Multiply the unpaid amount by the yearly rate, divide by 365 and multiply by the number of days late. For example, £1,000 at 11.75% for 30 days is £1,000 × 0.1175 ÷ 365 × 30 = £9.66.
What is the statutory interest rate on late payments in the UK?
For business-to-business debts that went late between 1 July and 31 December 2026 it is 11.75% a year: the Bank of England base rate of 3.75% on 30 June 2026 plus 8 points. You can also claim £40, £70 or £100 fixed compensation, depending on the size of the debt.
Can I charge a late fee if it is not in my terms?
In the UK and EU you can claim statutory interest and compensation from a business even if your terms do not mention it. In most other countries, including the US, Canada and Australia, you can only charge what was agreed, so put your late fee in your terms.
What is a reasonable late fee?
Many businesses charge 1% to 2% a month on overdue amounts, or a flat fee. Keep it in proportion to the invoice, put it in your terms before work starts, and check local limits on interest and penalties.
Does statutory interest apply to consumers?
No. The UK Late Payment Act and the EU rules cover business-to-business invoices. Late fees on consumer invoices must be agreed in advance and follow consumer protection law.
Is my data stored?
No. The calculator runs in your browser and nothing you enter is sent to BunnyDoc.
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