Late payment interest calculator UK
Free late payment interest calculator UK.
Enter the invoice amount and due date to calculate statutory late payment interest, fixed compensation, and a sentence you can paste into a chasing letter. There is no sign-up, and you can export the result for Excel or download the 50-invoice workbook.
Single-invoice estimate.
The default Bank Rate is set to 3.75%, checked against the Bank of England page on 24 July 2026. Change any assumption below to match the invoice you are reviewing. Your entries are calculated in this browser and are not uploaded by this tool.
Sources and freshness
Last checked: 24 July 2026. Default Bank Rate used on this page: 3.75%. Next Bank Rate decision due 30 July 2026.
Rates and compensation Editable statutory defaults
Copy-ready wording
Enter the invoice details to create a sentence for your chasing letter.
Scope: drafting aid for qualifying UK business-to-business commercial debts. Basis: simple interest over a 365-day year using the amount still unpaid and one rate period. Partial-payment dates are not modelled. Check the contract and eligibility before relying on or sending these figures. This is not legal advice.
Free: export this result or use the 50-invoice workbook. £4 pack: get editable letters, email drafts, an Excel log and README for up to 50 invoices. Generate the chase pack. Nothing is sent automatically.
Worked examples at 3.75% Bank Rate.
These examples use an annual statutory rate of 11.75%: 3.75% Bank Rate plus 8 percentage points. They are examples for drafting and checking, not legal advice.
Formula used.
Annual statutory rate = Bank of England base rate + 8 percentage points. Daily interest = invoice amount x annual statutory rate / 365. Interest estimate = daily interest x days overdue.
Fixed compensation is added by invoice value: £40 below £1,000, £70 from £1,000 to below £10,000, and £100 from £10,000 upwards.
Late payment interest calculator questions.
When can statutory late payment interest apply?
The statutory regime can apply to qualifying late payments between businesses. Contract terms, disputes and the circumstances of the debt can change what is appropriate to claim.
What rate does this calculator use?
The default annual rate is the Bank of England base rate plus 8 percentage points. Both values are editable so you can check the current rate and match the invoice being reviewed.
What fixed compensation can be added?
The statutory bands are £40 below £1,000, £70 from £1,000 to below £10,000, and £100 from £10,000 upwards. Use the reset button to restore the band.
Can I calculate interest for several invoices in Excel?
Yes. Export one result as a CSV or use the free 50-invoice Excel workbook for a debtor list. The workbook includes editable rates, formulas, filters and compensation bands.
Does SHVL send a demand or contact the customer?
No. The calculator creates figures and draft wording only. The optional chase pack creates editable files for review, and nothing is sent automatically.
Need the calculation for a whole aged-debtors list?
Export this result for Excel, use the 50-invoice workbook, or let SHVL handle the full batch: upload the CSV, preview the totals, then create the reviewable ZIP after checkout.
Download 50-invoice Excel calculator Upload CSV and preview Open sample pack first