I think the " customary 30 day's "as you stated is a big problem that most examiners have. Most seem to send out their invoice every 30 days and hope to get paid in another 30 days. So a title completed Jan1 they will not get paid till March 1. This way of book keeping only allows for larger amounts to build up and not be paid, However if there came a day where the gas station I go to tells me after I fill up that they will bill me in 30 days and I then have the "customary 30 days to pay" them , I may start invoicing my clients this way.

                        I always pick out my clients based on my terms not theirs, Unless I get very busy I prefer to bill once a week and to be paid in 7 days( somtimes their accountant maybe out , but after 14 days I cut them off.)  I also make sure my prices are on the high end ,so I can do little favor's for those who pay quick ( This also allows us to do a better quality of work then those on the low end ).

                        In the past I was going to charge late fee's , but If they have a problem paying their invoice they will have more of a problem with late fee's on top. I was very interested in having the client place the order with a charge card for the standard charges and billing them for any misc charges but as others on SOT have said it is going to be another cost. If it gets busy I would not rule out the charge cards for new clients or maybe having them send me a retainer.