Free tool

Late Payment Interest Calculator

Work out how much statutory interest and fixed compensation you can claim on overdue invoices under the Late Payment of Commercial Debts (Interest) Act 1998.

Defaults to today if left blank.
Amount you can claim
Daily interest rate
Days overdue
Interest owed
Fixed compensation
Total claimable
Bank of England base rate used: 4.50% (as of May 2026). If the base rate has changed, adjust your calculation accordingly.

How late payment interest works in the UK

The Late Payment of Commercial Debts (Interest) Act 1998 gives businesses and sole traders the statutory right to charge interest and claim fixed compensation when another business pays an invoice late. This applies to business-to-business (B2B) transactions, which covers most work carried out by tradespeople for landlords, property managers, contractors, and commercial clients.

Statutory interest rate

The statutory interest rate is 8% per year above the Bank of England base rate. The rate is calculated on a daily basis from the day after the agreed payment deadline until the debt is settled.

Fixed compensation tiers

On top of interest, you can claim a fixed sum as compensation for the cost of recovering the debt:

Debt amount Compensation
Up to £999.99 £40
£1,000 – £9,999.99 £70
£10,000 or more £100
This calculator is for information only. It is not legal or financial advice. If you are unsure about your rights, speak to a qualified solicitor or your local Citizens Advice.

Stop chasing. Let WOPA do it.

WOPA chases late payments automatically. Set reminders at 7, 14, and 28 days — and let WOPA handle the follow-up emails while you're on the job.

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