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 ...

Closely guard your credit card security code unless you are certain that a legitimate business needs it – and only if you initiate a transaction.

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

What Is a Credit Card Security Code? The security code is a set of three or four digits on your credit card that you may need to complete online or phone transactions.

A 2011 analysis for the California Judiciary Committee explained that credit card companies provided financial incentives to use ZIP code verification at the pump.