When it comes to paying with plastic at the cash register, you know the drill. A quick swipe, a signature and the contents of your shopping cart are yours. But sometimes the cashier asks for one more thing:"May I have your postal code, please?"
You may think it's necessary to complete the transaction or it may seem like a harmless piece of information to give out, so you go ahead and reveal it.
Why you shouldn't give retailers your postal code
