I respectfully disagree. That situation is common in hourly billing certainly. That doesn't mean you can't require a deposit upfront based on some sort of rough

I respectfully disagree. That situation is common in hourly billing certainly. That doesn't mean you can't require a deposit upfront based on some sort of rough estimate. The point isn't necessarily the amount, but that there is something. The client needs some skin in the game. Otherwise they're not actually a client. Plus it helps with your own cash flow, which is often far tighter than the client's (or prospect's) and, in any case, far more important to you than it is to them. :-)