Under the Late Payment of Commercial Debts Act we are entitled to charge interest on over due invoices. The standard in America seems to be 1.5% per month (18% annually). In the UK the rules AFAIK stipulate Bank of England Base rate + 8%, which currently means 8.5%. As I understand it this rate is the annual rate. That's quite a difference with the USA and I wonder if I'm misunderstanding the rules. Anyone else have any clarification they ca add?