To look up the full postal code for a city, access the website of the United States Postal Service. Use the tool for looking up ZIP codes, and enter the name of the city, optionally with an address, to find the postal code that corresponds to it.
When accessing the USPS website, click on Look Up a ZIP Code under the Quick Tools tab located on the left side of the page. This leads to the Look Up a ZIP Code page that allows visitors to search for the full postal code of a city using only the city name or a specific address.
In this page, type in name of the city, and the select the state in which the city is located from the drop-down menu. Providing this information is mandatory for finding a ZIP code. After making the selection, click on Find. This leads to a page that provides you with a list of all postal codes actively used in the city.
For a more specific search, type in the street address and the nature of the accommodation, whether an apartment, suite or other. Optionally, enter the name of the company in the first box. Then, enter the city name, and choose the correct state. Again, click on Find. This leads to the full postal code that corresponds to the particular address.