The postal code for an address is usually listed as the last item in an address after the city and state. If a person needs to look up the postal code for an address USPS.com allows her to search for a ZIP code by address, company and by the city.
A postal code is a series of numbers assigned to a postal address for the purpose of sorting mail. Postal codes are usually assigned to geographical areas but can also be assigned to individual addresses and institutions that receive a large volume of mail. Postal codes are also referred to as ZIP codes in the United States.