Late Payment & Statutory Interest Calculator
Work out the statutory interest and fixed compensation you can charge on an overdue commercial invoice, from the day after the due date to the day it's paid.
Calculate statutory interest
How statutory interest is worked out
If another business pays a commercial invoice late, you can charge statutory interest under the Late Payment of Commercial Debts (Interest) Act 1998. The rate is the Bank of England base rate plus 8 percentage points, and it applies from the day after the payment was due until the day it's paid.
The reference base rate is fixed for six months at a time: for debts becoming late between 1 January and 30 June, the base rate as at the previous 31 December applies; between 1 July and 31 December, the rate as at 30 June applies. The calculator can split the interest automatically if the debt spans more than one period.
Fixed compensation you can also claim
On top of interest you can claim a fixed sum for the cost of recovering each late invoice: £40 for debts under £1,000, £70 for £1,000 to £9,999.99, and £100 for £10,000 or more. This right is automatic and applies even if your contract says nothing about late payment.
Interest on late tax to HMRC
HMRC charges interest on overdue tax – Self Assessment, VAT, Corporation Tax and PAYE – at the Bank of England base rate plus 4%. It runs from the due date until you pay. Choose the HMRC option in the calculator to apply that rate instead of the commercial rate.
A County Court Judgment (CCJ) debt carries statutory interest at 8% a year. Select the consumer/private debt option for that flat rate.
Frequently asked questions – Late Payment & Statutory Interest Calculator
For business-to-business invoices, statutory interest is the Bank of England base rate plus 8% (11.75% in the first half of 2026), running from the day after the due date until payment. You can also claim fixed compensation of £40, £70 or £100 per invoice.
HMRC's late payment interest is the Bank of England base rate plus 4% (7.75% in early 2026). It applies to overdue Self Assessment, VAT, Corporation Tax and PAYE, from the due date until you pay. Select the HMRC option to use this rate.
Yes, for commercial debts. The right to statutory interest and fixed compensation is automatic under the Late Payment of Commercial Debts (Interest) Act 1998, whether or not your contract mentions late payment – unless the contract sets a different, substantial remedy.
The statutory reference rate is reset every 1 January and 1 July. If an invoice is overdue across one of those dates, the interest is calculated separately for each period and added together. Tick the 'split automatically' option and the calculator does this for you.