Statutory Interest Calculator
Money owed to you earns interest — usually 8% a year. Work out exactly what to claim, with the wording courts expect, ready to paste into your letter or claim form.
The principal debt only — before any interest or fees.
For an invoice, the day after its payment terms expired.
Leave blank to calculate to today.
How interest on money claims works
Statutory 8% — section 69 of the County Courts Act 1984 lets you claim simple interest at 8% a year on most debts and damages from the date the money fell due until judgment. This is the rate almost every small claim uses.
Business invoices — if both you and the debtor were acting as businesses, the Late Payment of Commercial Debts (Interest) Act 1998 gives you 8% plus the Bank of England base rate, and fixed compensation of £40, £70 or £100 per unpaid invoice depending on its size.
Contractual interest — if your contract or terms specify a late-payment rate, you claim that rate instead. Courts will enforce it provided it is not extortionate.
Interest keeps running at the daily rate until the debt is paid or the court gives judgment — which is why quoting the daily figure in a Letter Before Action concentrates minds.