We all get them ....
I typically don't do work for small companies and the big ones pay ... slow sometimes but they pay.
I made the mistake of doing some work for a person who was quite successful (I thought) as a favour for future joint ventures.
I did it not only at a discount from my usual retail rates but at a sizeable discount from the usual rates for that type of work. (I also don't normally do that type of work).
The problems started as soon as I showed up ... she had a fight with a client over her bill (and told the client to go elsewhere) and then started to bitch about how other people bill her and don't deliver. And then she launched into a complaint about an accountant who charged her BIG bucks (all of $25/hr) to clean up her books for her.
And naturally, she found an excuse to not be around when I finished.
Needless to say, I made sure I could pull out competitive quotes for the work. And I sat down to decide if I wanted to even pursue the bad debt I knew it would become (hint to self in future, don't do this when you're T'd off at the client!)
Every month she got sent a bill for the interest and then a little later a statement for the amount owing. And a few days after an email asking for payment.
The net result was it got to the point where she was fighting with me over charging tax. I ended up having to chase her for 9 months to get the final amount of the bill paid.
Not to mention getting a ruling from the appropriate tax authority.
It finally took a statement that I was going to see my lawyer in x days and that if she wanted to not be a subject in the discussion I needed payment prior to that.
Heck of a lot of work (and aggravation) for very little money -- and no chance of future joint ventures.
I found out later that she was barely scraping by and well below normal earnings. All the "I'm a great salesperson" was smoke and mirrors.