Calculate statutory interest and fixed compensation you are legally owed under the Late Payment of Commercial Debts (Interest) Act 1998. Uses the Bank of England base rate + 8% as required by UK law.
Important: This calculator applies to business-to-business (B2B) transactions only. The Late Payment of Commercial Debts (Interest) Act 1998 does not cover B2C (consumer) debts. The statutory rate applies unless a contract specifies a substantial remedy — consult a solicitor if in doubt.
Enter your invoice amount and payment due date, then click Calculate to see statutory interest and fixed compensation under the UK Late Payment Act.
12.75% p.a.
Interest Rate
£40–£100
Compensation
Daily
Basis
The Late Payment of Commercial Debts (Interest) Act 1998 — amended by the Late Payment of Commercial Debts Regulations 2002 and 2013 — gives UK businesses a statutory right to charge interest on overdue B2B invoices. Unlike contractual late fees (which require the client to agree), statutory interest applies automatically once a payment is overdue. You do not need a specific clause in your contract. You simply need an unpaid B2B invoice.
Calculated at the Bank of England base rate plus 8% per annum, applied daily from the day after the due date. The rate is fixed twice a year — on 31 December and 30 June — based on the BoE rate at that date.
£40 for debts under £1,000. £70 for debts between £1,000 and £9,999.99. £100 for debts of £10,000 or more. This is in addition to interest and applies per invoice, not per debtor.
Beyond the fixed compensation, you may also recover "reasonable costs of recovering the debt" — such as solicitor fees — if these exceed the fixed amount. The fixed compensation amount is a minimum, not a cap.
The fixed compensation under s.5A of the Act is determined by the size of the debt. These amounts apply per invoice and are recoverable in addition to statutory interest:
| Debt Amount | Fixed Compensation | Notes |
|---|---|---|
| Up to £999.99 | £40 | Most common for freelancers and small invoices |
| £1,000 – £9,999.99 | £70 | Mid-range invoices for services and B2B work |
| £10,000 or more | £100 | Minimum — you may also claim reasonable recovery costs above this |
The statutory interest rate is the Bank of England base rate on the relevant reference date, plus 8%. The reference date is fixed twice per year — 31 December for invoices in the first half of the year (January–June), and 30 June for invoices in the second half (July–December). Once fixed, the rate applies to the entire accrual period for that invoice, even if the BoE subsequently changes its base rate. At the current BoE base rate of 4.75%, the statutory interest rate is 12.75% per annum.
Verify your contract is a B2B commercial contract, and that payment is genuinely overdue (past the contractual due date, or past 30 days if no terms are agreed for public authorities, 60 days for commercial).
Use this calculator to determine the exact statutory interest (BoE base rate + 8%, accruing daily) and the fixed compensation amount (£40, £70, or £100 depending on the debt size).
Write to the debtor setting out the original debt, the interest accrued, and the compensation. Quote the Late Payment of Commercial Debts (Interest) Act 1998. Give a specific deadline — typically 7–14 days.
If no response, send a final notice before collections. Document all communication with dates. Use certified or recorded post for the final notice.
For debts up to £100,000, use Money Claim Online (MCOL) to file in the County Court. For larger debts or complex disputes, instruct a solicitor. The Small Business Commissioner can also assist SMEs with disputes.
Use these alongside the UK Late Payment Act Calculator to build a complete debt recovery workflow
Generate professional UK payment reminder emails with the right tone for each stage of escalation
Build a complete step-by-step collection action plan with exact dates and industry-specific timing