Bounced cheque. They pay me a $35 penalty to cover bank charges as well as owing me the fees they bounced immediately. From then on they must pay in cash, at the beginning of the week before care is provided. Also, I may charge them a late fee as well, depending on how ticked I am, because now their payment is over a week late by the time I find out that a cheque has been bounced. Plus, they have to know their cheque bounced before I know, so there is that honesty issue as well. This is all laid out in my contract.