The U.S. Postal Service provides ZIP code assistance at its postal facilities and online at its website, USPS.com. According to the USPS, ZIP codes can be obtained by providing a street address, city and state.
Zoning Improvement Plan codes were first implemented in July 1963. The Advisory Board of the Post Office Department ensured that every address in the United States was assigned a ZIP code. ZIP codes have assisted the USPS in streamlining mail processing time. The code has also been used to measure the impacts of housing and road developments, track demographic changes and estimate real estate values.