Late payment interest calculator (UK)
Work out the statutory interest and fixed compensation you can add to an overdue business-to-business invoice under the Late Payment of Commercial Debts (Interest) Act 1998.
For invoices between businesses only. Different rules apply to consumers.
You can claim
- Invoice amount
- Fixed compensation
- Total
How it's calculated
| Period | Days | Rate | Charged on | Interest |
|---|
Official sources
General information, not legal advice. Rates come from the Bank of England and GOV.UK; the rate is fixed using the base rate on 30 June or 31 December before interest starts.
FAQ
What is the statutory late payment interest rate?
8% a year above the Bank of England base rate. The base rate used is the one in force on 31 December (for debts that become late between January and June) or 30 June (July to December), and it stays fixed for that debt.
How much fixed compensation can I add?
£40 for debts under £1,000, £70 for £1,000 to £9,999.99, and £100 for £10,000 or more, on top of the interest.
When does an invoice count as late?
After the agreed payment date. If no date was agreed, the law treats payment as late 30 days after the customer receives the invoice or the goods or service, whichever is later.
Does this apply to consumers?
No. The Act covers business-to-business transactions only.