Discover what a billing ZIP code is and why it's important for credit card transactions. Learn when it's required and how to find your billing ZIP code.

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.

But you don't have to tell merchants your ZIP code, at least not in California. Last week, the state's Supreme Court ruled that it is illegal for retailers to demand ZIPs during a credit card ...

As Forbes magazine noted in a recent story headlined "Never Give Stores Your ZIP Code," Harte-Hanks promises accuracy rates "close to 100 percent" - thanks to its "extensive, proprietary matching ...