Undercharged for an item or service? Why you need to fess up

While it may seem like a fortuitous turn of events, ethically and, in some cases, legally, financial errors made in your favor shouldn't be accepted and can, in fact, be considered theft. Instances of banks erroneously depositing large amounts of money in consumers' accounts, for example, did not result in early retirements on a tropical island for the consumers. Or when a staff member accidentally gets paid at the CEO rate instead of the Lowly Line Worker rate, they have had to give the money back. While disappointing, most people understand why that "found" money has to be returned.

But things get a little blurrier when it comes to less dollar-intensive purchases at a grocery or department store. Consumers often rationalize the error as if it was a Monopoly maneuver: "Bank error in your favor! Collect $75!"