Creative Designs

A lot of your leeway may depend on your contract. . .you did get one, didn't you?

If your agreement describes anticipated start and end dates and outlines the tasks you agreed to do and the amount you would be paid, then you can simply lean on that information.

But, if your contract isn't clear about such things, or it doesn't exist, you may be at the mercy of your clients.

That said, it's not unreasonable to submit an invoice. I would create one that breaks out all the tasks you've accomplished in the order completed, with a price attached. Mark with an asterisk or something the "extras" you've provided that are off-schedule, and note this at the bottom with something like "*provided, but not part of the original agreement."

List payment as due on receipt of bill, with some reasonable but modest increment for delay, as this may encourage your clients to deal with the problem rather than put it aside. (I sometimes offer a slight discount for payment within 4 business days, usually when dealing with large corporations)

Then write a cover letter that says pretty much what CreativeJen suggests-- tell the client that you're sending the invoice because of the delays and that they should contact you with any questions.

Do not accuse the client of bad faith. Do not complain do not threaten. In the world in which I work, addressing someone as "Lady" or "Ladies," like calling a stranger "sweetheart" or "girlie," is considered insulting.