Contractual Interest Late Payment Calculator

You should use this calculator if interest charged on overdue debt is defined in your terms of business and differs from that in the UK Late Payment Act. If your terms of business do not define interest on late payment, or if they refer to the UK Late Payment Act, then you should use our statutory interest calculator.

If you use contractual interest then you should change the interest rate field on the calculator accordingly, and set the Interest base rate to ‘No’ if your terms of business specify a set interest rate rather than a rate above base rate.