The word ZIP in Zip Code stands for “Zone Improvement Plan” and was established by the United States Postal Service. They are numerical codes that designate a local area or entity for the delivery of mail by a postal carrier.
ZIP Codes may consist of 5, 7, 9, or 11 digits and may refer to a street section, a collection of streets, an establishment, a structure, or a group of post office boxes.
While the numbers are rarely a key piece of information in an investigation, it is helpful for private investigators to have an understanding of the codes to help conduct more effective address searches. Private investigators who specialize in skip tracing and locating missing persons would benefit from having a good knowledge of the codes and of various zip code search tools and websites.
Zip Code Lookup Tools
Many websites allow you to conduct searches and reverse zip code searches and lookups for free. Following is a list of recommended search tools and websites:
- United States Postal Service City State / ZIP Code Associations – Use the USPS website to lookup zip codes by street address, city, and state or even find all codes within a particular state. You can also enter a company name to find its associated code.
- Addresses.com – Includes people search tools such as white pages, yellow pages, public records searches, reverse search directories, area code searches and more.
- Intelius People Search – Public records and much more.
- National Address Server – Enter an address and get the address with the Zip Code+4
- Zip Code Download – Accurate United States Postal Service databases, distance calculation tools, includes other data and Mexico and Canada as well.
- Zip Code Lookups – This is an excellent search resource that allows you to:
- Look up ZIP Codes and city names nationwide
- Displays boundary maps and aerial views
- Display a list of ZIP Codes within a city
- Display a list of ZIP Codes within a county
- Display a list of postal Carrier Routes in a particular area
- Display a list of street names within a particular area
- Display a list of codes in a particular radius using a center ZIP Code
- Display a list of house numbers within a specific code
- Look up and verify U.S. addresses
- Look up and verify Canadian addresses
- Locate anyone nationwide. Search by name, phone number or address
- Lookup Tool – Free lookup tool for valid postal codes. Use this search tool to find the city and state, plus: county name and FIPS code, area code, time zone latitude and longitude, and the MSA/PMSA
Zip Code Search Reference Books
The following books may help you learn more on the subject: