In today’s mail I received an invoice from a store with which I do more than just a fair amount of business. At the moment, I’m caught up on what I owe them.

The invoice I received today indicated that I had a balance due of $0.00 and I must remit this payment on or before the due date of 03/30/09

Why do companies invoice their customers for 0 balances?

I don’t want to hear about computer generated billing runs. I don’t know what language their billing system is written in, but I’d be apt to wager a shekel or two that the language has an IF function.