A postal code is a series of letters or digits or both, sometimes including spaces or punctuation, included in a postal address for the purpose of sorting mail. Postal codes are used by postal services to determine where a piece of mail is being sent to, and they help simplify the task of bringing mail to its destination. Although postal codes are usually assigned to geographical areas, special codes are sometimes assigned to individual addresses or to institutions that receive large volumes of mail, such as government agencies and large commercial companies. Postal services have their own formats and placement rules for postal codes. In most English-speaking countries, the postal code forms the last item of the address, following the city or town name, whereas in most continental European countries it precedes the name of the city or town.
Postal codes are used in over 160 countries worldwide. They are also important for credit card transactions, where the credit card ZIP code is part of the geographical identifier associated with a credit cards billing address. Postal codes and ZIP codes are important for proper authorization of credit card transactions, and they help verify the identity of the cardholder and protect both the cardholder and the merchant.
