⏰Late Payment Interest Calculator

About this tool

Choose UK statutory interest or your contract's own rate, then enter the invoice amount, the date payment was due and the date it was paid or today. For statutory interest, enter the Bank of England base rate that applies. The calculator shows days late, daily and total interest, the fixed compensation and the total you can claim, with a summary to copy into a reminder.

Your right to late payment interest in the UK

The Late Payment of Commercial Debts (Interest) Act 1998 lets a business charge interest when another business pays late, unless the contract sets a different, substantial remedy. The statutory rate is 8% a year plus the Bank of England base rate, using the base rate on 30 June for invoices due in the second half of the year and on 31 December for the first half. Interest is simple, not compound: amount × annual rate ÷ 365 × days late. You can also claim fixed compensation for the cost of chasing the debt: £40 for debts under £1,000, £70 for £1,000 to £9,999.99, and £100 for £10,000 or more. With a 4% base rate, a £2,400 invoice paid 45 days late accrues about £35.51 of interest plus £70 compensation. Payment is late after the agreed terms or, if none were agreed, 30 days after the invoice or delivery. Mentioning your right to statutory interest in your terms and reminders often speeds payment. Honest limits: the base rate default is an example, so check the rate for the relevant date. The Act applies between businesses, not to consumers, and reasonable recovery costs above the fixed sum aren't calculated. Not legal advice. The invoice generator creates invoices and the payment terms calculator finds due dates.

Frequently asked questions