Free UK late payment calculator
Paid late by another business? The law says you’re owed interest.
Under the Late Payment of Commercial Debts (Interest) Act 1998 you can charge 8% over the Bank of England base rate, plus £40, £70 or £100 fixed compensation per invoice. See exactly what you can claim, with the working shown.Charge 8% over the Bank of England base rate, plus £40, £70 or £100 fixed compensation per invoice, under the Late Payment of Commercial Debts (Interest) Act 1998.
- 11.75% a year
- Statutory rate today: 3.75% base rate + 8%.
- £40 · £70 · £100
- Fixed compensation per invoice, set by the invoice value.
- £0 VAT
- Interest and compensation are outside the scope of VAT.
You can claim
£147.26
£77.26 interest + £70.00 compensation · 96 days late
The working
Late Payment of Commercial Debts (Interest) Act 1998
- 1
1 Days late
Interest runs from 1 Jul 2026 to 4 Oct 2026
96 days
- 2
2 Reference rate
Base rate in force on 30 Jun 2026 (interest starts in July)
3.75%
- 3
3 Statutory rate
3.75% + 8%
11.75% a year
- 4
4 Daily interest
£2,500.00 × 11.75% ÷ 365
£0.8048
- 5
5 Statutory interest
£0.8048 × 96 days
£77.26
- 6
6 Fixed compensation
Debt of £1,000 to £9,999.99
£70.00
No VAT is charged on statutory interest or compensation. Send it as a separate invoice, not added to the original.
For business-to-business debts where your contract doesn’t set its own interest rate. Not legal advice.
How it’s worked out
Simple daily interest, at a rate that doesn’t move.
Sources: gov.uk late commercial payments guidance, Bank of England Bank Rate history, legislation.gov.uk.
amount × (base rate + 8%) ÷ 365 × days late
Interest starts the day after the due dateInterest starts the day after the due date
The “relevant day” is the agreed payment date (s.4(2) of the Act). Interest runs every day from the day after it until the invoice is paid, and is always divided by 365, even in a leap year.It runs every day until payment, always divided by 365.
The base rate is fixed for the life of the debtThe base rate is fixed for the debt
We use the Bank of England base rate in force on 31 December for interest starting January to June, or on 30 June for interest starting July to December.The rate in force on 31 December (interest starting Jan to Jun) or 30 June (Jul to Dec).
Compensation is a fixed sum per invoiceCompensation is fixed per invoice
Claimed once per invoice to cover the cost of chasing, on top of the interest.Claimed once per invoice, on top of the interest.
| Debt under £1,000 | £40.00 |
| £1,000 to £9,999.99 | £70.00 |
| £10,000 or more | £100.00 |
When it doesn’t applyWhen it doesn’t apply
Debts owed by consumers, and contracts that set their own rate for late payment. ClaimLateInterest is a calculator and reminder tool, not legal advice.Consumer debts, and contracts with their own late-payment rate. Not legal advice.
For sole traders and small firms
Chasing late invoices every month?
ClaimLateInterest watches your overdue invoices, sends polite-to-firm reminders that quote the interest owed, and raises the claim invoice in one click.
- 1
Import your invoices
Upload a CSV from any accounting tool. FreeAgent and Xero sync are planned.
- 2
Reminders on day 1, 14 and 30
Friendly, then firm, then final notice, each quoting the interest to date.
- 3
Claim invoice in one click
A PDF with the working and the statute reference. No VAT.
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Invoices
As at 28 Sep 2026
Total claimable
£877.91
Overdue
£20,190.00
Recovered
£106.62
Harbour Joinery Ltd
INV-0142
£400.59
Northgate Print Co.
INV-0147
£141.70
Pennine Signs & Graphics
INV-0138
£143.65
Wren & Fielding LLP
INV-0133
£106.62