The client's that hire a PI come in two major categories. There are
corporate clients and there are private clients.
Corporate clients include law firms, businesses, national PI agencies, and associate PIs. A PI will typically do business with these clients without a contract because they are professional, protective of their reputation and pay invoices in a timely manner.
Private clients are a mixed bag. There is the wealthy client who just wants results and doesn't care about the cost and then there is the woman who...