In my case it is not about extending credit, it is about the final payment. The smallest I have been able to arange a final payment is 20%. So... on a 30k job, the last payment, (not payable until AFTER completion) is 6K. Of course, that is all profit, assuming I priced the job correctly. Getting screwed out of 6K hurts a small business.
If I could get the final payment down to 10%, at least I would make some profit when I get screwed. Doesn't happen often, but it does happen and it is always the wealthy who do it.