UK Late Payment Interest Calculator

Calculate how much you’re owed when clients pay invoices late, including statutory 8% interest and fixed penalties under UK law.

Invoice Amount (£)

Days Late

Include Fixed Penalty (£40 if invoice ≥ £1000)

You Are Owed:

Interest: £6.58
Penalty: £40.00
Total: £1046.58

Legal Reference: Based on the Late Payment of Commercial Debts (Interest) Act 1998.

This calculator assumes a standard 8% interest rate above Bank of England base rate (currently 0%) and includes fixed late payment penalties where applicable.