Late Payment Interest Calculator (Statutory)
Calculate statutory interest on overdue invoices at 8% plus the Bank of England base rate, plus the £40-£100 fixed compensation sum, across multiple invoices.
Total amount due
£5,040
Days overdue0
Interest accrued£0
Fixed late-payment compensation£40
Statutory rate applied11.8%
Statutory interest and compensation on an overdue invoice
Under the Late Payment of Commercial Debts (Interest) Act 1998, you're entitled to charge statutory interest on an overdue business invoice at the Bank of England base rate in force on the first day of the relevant reference half-year (1 January or 1 July) plus 8 percentage points. With the base rate at 3.75% for the period from 1 July 2026 (last set by the Monetary Policy Committee on 30 July 2026), that gives a statutory rate of 11.75% a year — and this resets whenever the Bank of England changes the base rate at the start of the next half-year reference period.
What's included in the calculation
- Statutory interest at 11.75% a year (Bank of England base rate 3.75% plus an 8-percentage-point margin) for the period from 1 July 2026, applied for each day the invoice remains unpaid
- The fixed compensation sum for debt recovery costs, which is tiered by debt size: £40 for debts under £1,000, £70 for debts between £1,000 and £9,999.99, and £100 for debts of £10,000 or more
- Support for multiple invoices at once, applying the correct reference-period rate to each based on when it fell due
