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.

In the zip code 06759, the first "0" stands for Connecticut, Maine, Massachusettes, New Hampshire, New Jersey, Rhode Island, or Vermont; the "67" stands for the Waterbury Sectional Center Facility ...

Massachusetts and New Jersey, for example, block collection of any personal identification information. Whether a ZIP code is that personal, however, remains unclear.

English: USA 10-cent postage stamp, 1973: "It all depends on ZIP code". (Photo credit: Wikipedia) How is it that a simple five-digit ZIP code provides any insight into who you are? After ...