UK & EU late payment interest calculator

Invoicing a business that pays late? By law you can usually add interest and a fixed compensation fee. Enter the invoice to see how much.

Not legal advice. Applies to business-to-business debts. UK: the reference rate is the Bank of England base rate on 30 June or 31 December before the debt became overdue. EU: rules differ slightly by country. Check with a professional before taking formal action.

How the calculation works

UK (Late Payment of Commercial Debts (Interest) Act 1998)

Fixed compensation: £40 for debts under £1,000; £70 for £1,000–£9,999.99; £100 for £10,000 or more.
Interest: debt × (Bank of England base rate + 8%) ÷ 365 × days overdue.

EU (Directive 2011/7/EU)

Fixed compensation: €40.
Interest: debt × (ECB reference rate + 8%) ÷ 365 × days overdue.

Example: a £5,000 invoice paid 30 days late with a 3.75% base rate → 11.75% a year → £48.29 interest + £70 compensation = £118.29.

Chasing the invoice?

DueKindly builds a 5-step reminder plan for every invoice and writes each email — from a friendly heads-up to a final notice that includes this late fee. Try it free, no signup.

Add this calculator to your website

Free for blogs, accountants and freelancer communities. Copy the code below:

Embed code