UK late payment interest & statutory interest calculator
Work out UK late payment interest (statutory interest) and fixed recovery compensation on an overdue UK B2B invoice under the Late Payment of Commercial Debts (Interest) Act 1998. Runs entirely in your browser — nothing is uploaded.
Not legal advice. Qualifying commercial (business-to-business) debts only. A different substantial contractual remedy can change entitlement. Cross-check with GOV.UK and the Office of the Small Business Commissioner calculator. Verify the Bank of England reference rate for your overdue period.
Interest starts the day after the due date.
Use today if still unpaid, or the date paid.
Default 3.75% (BoE rate on 30 Jun 2026 / 31 Dec 2025 — check for your period).
Days overdue = calendar days from the day after due date through the “as of” date (inclusive of both ends in the usual day-count used here).
Fixed compensation (recovery cost): £40 if debt < £1,000; £70 if £1,000–£9,999.99; £100 if £10,000+.
Reference rate is the BoE base rate in force on 31 Dec (for interest starting 1 Jan–30 Jun) or 30 Jun (for interest starting 1 Jul–31 Dec). It is fixed when interest starts for that debt.
Free sample chase email
Day-1 polite reminder (UK English). Swap the placeholders before you send. The full chase pack (more emails + calculator workbook) is the paid £19 version when the store is live — this page stays free and does not take payment.
Subject: Invoice [Invoice Number] — a quick reminder
Hi [Client Name],
Invoice [Invoice Number] for £[Amount], due on [Due Date], still shows as unpaid on my side.
Could you confirm it is in this payment run, or tell me if anything on the invoice needs correcting?
Thank you,
[Your Trading Name]
Paid version: £19 chase pack + calculator. Checkout opens when the store is live. This page does not take payment.
One click adds 1 to an anonymous tally. No email, no name, no cookie, no payment.