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

Your credit card's security code is a three- or four-digit number that helps protect you against credit card fraud. Learn how to find it and why it's important.