Jeremy, this is all part of business life I'm afraid. The normal course of action is a) do the work b) send an invoice 7 day, 14 day, 30 day etc c) get paid When you're dealing with high profile companies, like in the City, then sometimes one has to wait a full three months for their money. Most companies won't pay on invoice, but wait for their monthly statement to arrive. If you are a small company, and you want payment on completion, then stipulate that at the time of survey, or if they do want an invoice sent simply add an administration charge. It's not all bad when they do want an invoice sent as you can then send them other details about your services, this is called advertising and marketing! If you were to put pressure on your current clients to be paid on completion then they may just go elsewhere to Joe Bloggs down the road. At the end of the day, you know you're going to get paid from these customers so why bother 'rocking the boat', I would just keep the status quo.