Your billing zip code, or credit card postal code, is the five-digit number on the bottom right, which in this sample is 90210. This would be the zip code associated with your billing address. It ...

A validation code—also known as a CVV, CV2, or CVV2 code—is a series of three or four numbers located on the front or back of a credit card.

A credit card security code provides protection against fraud in online and over-the-phone transactions.