💰 Late Payment Interest Calculator

Calculate the interest you're legally entitled to charge on overdue invoices under US or UK late payment law.

⚠️ This calculator provides estimates based on general late payment rules. Actual entitlements may vary. This does not constitute legal advice.

Invoice Details

Jurisdiction *

UK Rate: Under the Late Payment of Commercial Debts Act 1998, the statutory rate is 8% per annum above the Bank of England base rate (currently ~8% total). This applies to B2B debts.

Invoice Amount *

Annual Interest Rate (%) *

Invoice Due Date *

Calculate To Date *

Interest Type

Calculation Result

Fill in the invoice details and click "Calculate Interest" to see the result.

Related Resources

→ Invoice Due Date Calculator
→ Late Payment Laws in the US
→ Late Payment Laws in the UK
→ How to Handle Non-Paying Clients