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.

In one high-profile case, the home furnishings and cookware chain Williams-Sonoma matched names from its credit card sales and ZIP codes with a database to obtain addresses and other information ...