Postal Zip Codes

Postal Zip Codes

The postal zip codes is the system of postal codes used by the United States Postal Service (USPS). The letters ZIP, an acronym for Zone Improvement Plan, are written properly in capital letters and were chosen to suggest that the mail travels more efficiently, and therefore more quickly, when senders use it. The basic format consists of five numerical digits. An extended ZIP + 4 code includes the five digits of the postal zip codes, a hyphen and then four more digits, which enables a piece of mail to be directed to a more precise location than by the postal zip codes alone. The term postal zip codes was originally registered as a servicemark (a type of trademark) by the U.S. Postal Service but its registration has since expired.

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