Thinking of starting a fee of £5 per day for late payment. Does anyone else charge a fee? And if so, has it resolved issues with late payers? I now invoice parents on the first of the month for the full month in advance, however it is taking me a week to chase vouchers/cheques, so still getting paid mid month in theory. Would a £5 per day cause ill feeling, or remind my parents I am running a business?!