UK Late Payment Interest Calculator (2026)
Calculate the statutory interest and fixed compensation you can claim on a late-paid UK B2B invoice under the Late Payment of Commercial Debts (Interest) Act 1998. Current statutory rate: 11.75% APR (Bank of England base rate 3.75% plus 8%).
Last updated: 8 May 2026.
UK statutory late payment interest is 11.75% APR (BoE base 3.75% + 8%) under the Late Payment of Commercial Debts (Interest) Act 1998, plus £40, £70 or £100 fixed compensation by debt size. The right is automatic on UK B2B contracts. More detail + scope
Summary
This calculator computes statutory late payment interest and fixed compensation for any unpaid UK B2B invoice. Inputs: invoice amount, due date, payment date or today. Outputs: daily interest rate, total interest accrued, fixed compensation charge by debt size, and total now due. Updated for 2026 Bank of England base rate of 3.75%.
This page covers
UK statutory late payment interest calculation: statutory rate, fixed compensation, day count, claim method
Not covered here
General invoice finance education (see /guides/), individual provider reviews (see /providers/), full late payment legal guide (see /unpaid-invoices/late-payment-interest-rate/)
Calculator
| Item | Value |
|---|---|
| Invoice amount | £5,000 |
| Statutory rate | 11.75% (BoE base 3.75% + 8%) |
| Days overdue | 60 |
| Daily interest | £1.61 |
| Total interest accrued | £96.58 |
| Fixed compensation (debt £1,000 to £9,999.99) | £70.00 |
| Total interest + compensation due | £166.58 |
| Total now due including principal | £5,166.58 |
Source: Late Payment of Commercial Debts (Interest) Act 1998; Bank of England base rate 3.75%
Fixed compensation tiers: £40 under £1,000, £70 from £1,000 to £9,999.99, £100 at £10,000 and above, per overdue invoice.
View as plain-text Markdown
### Worked example: £5,000 invoice paid 60 days late at the statutory rate | Item | Value | | --- | --- | | Invoice amount | £5,000 | | Statutory rate | 11.75% (BoE base 3.75% + 8%) | | Days overdue | 60 | | Daily interest | £1.61 | | Total interest accrued | £96.58 | | Fixed compensation (debt £1,000 to £9,999.99) | £70.00 | | Total interest + compensation due | £166.58 | | Total now due including principal | £5,166.58 | Source: Late Payment of Commercial Debts (Interest) Act 1998; Bank of England base rate 3.75% Fixed compensation tiers: £40 under £1,000, £70 from £1,000 to £9,999.99, £100 at £10,000 and above, per overdue invoice.
“Statutory interest is what you are legally entitled to claim, not what you are guaranteed to collect. The figure is the entitlement; whether you pursue it, and whether the debtor pays, is a separate commercial decision.”
How the calculation works
Daily interest = Invoice principal x annual rate divided by 365. Multiply by days overdue (paid date minus due date). Add the fixed compensation charge by debt size: £40 under £1,000, £70 between £1,000 and £10,000, £100 at £10,000 and above.
Worked example: £5,000 invoice, 60 days overdue, statutory 11.75% rate. Daily interest = (5000 x 0.1175) / 365 = £1.61. Sixty days = £96.58. Plus £70 fixed compensation = £166.58 total interest and compensation owed on top of the £5,000 principal. Total now due: £5,166.58.
When statutory interest applies
The right applies automatically to any UK B2B contract where no other interest rate is contractually agreed. It does not apply to consumer transactions or contracts where you've agreed an alternative substantial remedy. You can claim statutory interest even if the customer eventually pays the principal.
If the customer still won't pay
After 30 days overdue, send a letter before action. After 14 days more without payment, you can issue a money claim online, file a statutory demand if the debt is over £750, or sell the invoice for immediate cash.
Director, Best Business Loans Ltd
Oliver leads Market Invoice's editorial and comparison research. With a background in UK commercial finance, he oversees provider analysis, rate verification, and industry reporting across all verticals.
Last reviewed: 12 June 2026