Early this year I had a local plumber do some work in my basement, including removing an old cement laundry tub and replacing some spigots. He did a decent job in spots, but a shabby job in others (chipped a cement wall up pretty good, but didn't fix it, etc.). I paid him on the spot for most of the work (about $600), but he said he'd bill me for some remaining items he had to get a price on (about $150 worth). Never got the bill.
I didn't plan on using him again, but my water heater kicked the bucket two days before I was expecting company, so I had to use him for that. He did a good job on it. That was over two months ago. Finally, last week I got the bill for that and for the remaining $150 from the previous job. Two days later I mailed a check.
This morning the guy calls and says, "I just wanted to check if you sent the payment, because I recently changed my business address to a P.O. box, and people have been getting mail sent back to them. I just wanted to check."
What, am I an idiot? The post office doesn't forward mail now? When I told him I sent payment last week, he said "Oh, okay," and hurredly got off the phone. Funny, but he didn't give me the alleged new billing address.
Moral of story: If, for any reason, you're paranoid about receiving payment for your services -- but you'd like to retain the customer -- take more than three freaking seconds to devise an excuse for calling.
Time to find a new plumber.