If another business pays you late, UK law lets you charge statutory interest. That is 8% plus the Bank of England base rate. At the base rate of 3.75% (since 18 December 2025) that is 11.75% a year. You can also charge a fixed sum of £40, £70 or £100, depending on the size of the debt. This is for business customers only, and not if your contract sets a different rate. Not legal advice.
| Debt | Fixed sum, and interest a day at 11.75% |
|---|---|
| £500 | £40 fixed sum, and 16p a day in interest at 11.75% |
| £2,500 | £70 fixed sum, and 80p a day in interest at 11.75% |
| £12,000 | £100 fixed sum, and £3.86 a day in interest at 11.75% |
12 lines you can copy
Twelve lines for an invoice or an email, for UK business customers only. For the reminder emails themselves, see the reminder pages linked below. Replace every [BRACKET] with a real fact.
Jump to: Before you add interestAdding itA contract with its own rateA customer who objectsNotes to yourself
- Before you add interestInvoice [NUMBER] for [AMOUNT] was due on [DATE]. It is now [NUMBER] days overdue. Under the Late Payment of Commercial Debts (Interest) Act 1998 I am entitled to claim interest and a fixed sum. Before I do, can you tell me when I can expect payment?
- Offer to leave it outI would rather not add interest. If payment reaches me by [DATE], I will not charge it.
- Point to your termsMy payment terms were on the invoice and in the quote of [DATE]: [TERMS]. Interest is due on late invoices at the statutory rate.
More examples, by situation
Adding it
- Add interest to the invoiceInterest on invoice [NUMBER]: [AMOUNT] at [RATE]% for [DAYS] days is [INTEREST]. The fixed sum for a debt of this size is [40 / 70 / 100] pounds. The new total is [TOTAL]. A new invoice is attached.
- Show your workingI have added statutory interest from [DUE DATE]. The working is below: debt, rate, days, daily amount.
- Interest keeps runningInterest keeps running at [DAILY AMOUNT] a day until payment.
A contract with its own rate
- Your contract sets a rateOur agreement of [DATE] sets late interest at [RATE] a year. That rate applies instead of the statutory rate. Interest to date is [AMOUNT].
A customer who objects
- It is the amount the law allowsThe interest is the amount the law allows between businesses. If you think the invoice itself is wrong, tell me which line and I will check it.
- You agreed to leave it outThank you for paying. I have not charged the interest, as agreed on [DATE].
- Waive the fixed sumI can waive the fixed sum if the invoice is paid in full by [DATE]. The interest to date remains [AMOUNT]. [ADD IF TRUE: ONLY IF YOU ARE HAPPY TO OFFER THIS.]
Notes to yourself
- What to recordRecord: the date the invoice was sent, the due date, the base rate on the 30 June or 31 December before interest started, the days late, the daily interest.
- A private customer? StopIf the customer is a private person, not a business, stop: this law does not apply. See the GOV.UK court claim page.
Download these examples
The same text as this page, in one file, with the gaps ready to fill in.
What to avoid
- Charging interest to a consumer. The GOV.UK pages are about business customers.
- Charging the fixed sum more than once for the same payment. GOV.UK says once for each payment.
- Adding interest without saying which rate and dates you used.
- Guessing the base rate. Use the Bank of England page and say the date you read it.
- Promising court action you do not intend to take.
Official pages. Rules differ by country. Not legal advice: check the rules that apply to you.
- GOV.UK: Interest on late commercial payments. It says: "The interest you can charge if another business is late paying for goods or a service is 'statutory interest' - this is 8% plus the Bank of England base rate for business to business transactions. You cannot claim statutory interest if there's a different rate of interest in a contract." Read 5 October 2026.
- GOV.UK: Claim debt recovery costs on late payments. The fixed sum is £40 up to £999.99, £70 from £1,000 to £9,999.99 and £100 for £10,000 or more. It says: "You can only charge the business once for each payment." Read 5 October 2026.
- GOV.UK: Late commercial payments: when a payment becomes late. It says: "If you do not agree a payment date, the law says the payment is late 30 days after either: the customer gets the invoice; you deliver the goods or provide the service (if this is later)." Read 5 October 2026.
- GOV.UK: Make a court claim for money. It says: "You can apply to a county court to claim money you're owed by a person or business" and "A mediation service could be quicker and cheaper than going to court." Read 5 October 2026.
- Bank of England: Interest rates and Bank Rate. Bank Rate held at 3.75% on 17 September 2026; the last change took effect on 18 December 2025. Next decision due 5 November 2026. The Bank's page is the place to check the rate on the day you write. Read 5 October 2026.
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Let the tools do the sums
Both are free.
Late Payment Chaser (UK)
What you give it: The unpaid amount, the invoice date, and the due date if you agreed one.
What you get: What you can claim under UK late-payment law, worked out with a script and shown with official sources, and three reminder emails to send. UK business-to-business debts only. Not legal advice.
Free. It also works as a paste-in text in a chatbot; there the assistant does the arithmetic, so check its working.
Invoice Checker
What you give it: An invoice, yours or one you received, as text. It cannot read a picture or a scan.
What you get: Every line, the subtotal, the discount, the tax and the total worked out again, and every difference listed. It lists common fields that are missing and flags date, currency and rounding problems. No tax advice. Without a code tool it shows the sums by hand and says they need checking.
Can I claim interest on a late payment?
Yes, when the customer is another business. GOV.UK says the interest you can charge if another business is late paying for goods or a service is statutory interest. It does not cover a private customer. A different rate in your contract replaces the statutory rate.
What is the statutory late payment interest rate?
GOV.UK: 8% plus the Bank of England base rate for business to business transactions. With the base rate at 3.75%, that is 11.75% a year. Which base rate applies to a given debt is set by the Late Payment Order 2002: our calculator page names the rule and links the Order.
How do I calculate late payment interest?
Multiply the debt by the yearly rate, divide by 365 for a daily amount, and multiply by the days late. GOV.UK's example: £1,000 at a 0.5% base rate is £85 a year, 23p a day and £11.50 after 50 days. At today's rate: £2,500 at 11.75% is £293.75 a year, about 80p a day, and £36.22 for 45 days (the daily amount is not rounded first), plus the £70 fixed sum.
Is there a free late payment interest calculator?
Yes. Ours is free: the late payment interest calculator, linked at the top of this page, shows the sums and the rate for your due date.
When does a payment count as late?
If you agreed a date, that date. If you did not, GOV.UK says it is late 30 days after the customer gets the invoice, or after you deliver, if that is later.
Questions people ask
What do I do with the [BRACKETS]?
Replace each one with a real fact. If you cannot, delete the line. Never leave a bracket in what you send.
Is this legal advice?
Not legal advice. For a large debt, a dispute or court, get advice.
More
Sources
- Interest on late commercial payments, read 5 October 2026
- Claim debt recovery costs on late payments, read 5 October 2026
- Late commercial payments: when a payment becomes late, read 5 October 2026
- Make a court claim for money, read 5 October 2026
- Interest rates and Bank Rate, read 5 October 2026