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Zip codes

Abbreviation ZIP comes from Zone Improvement Plan. ZIP codes are applied for faster sorting of mail and delivery acceleration. Originally they consisted of five digits, but in 1980th years have been expanded to nine digits which are written via a hyphen - XXXXX-YYYY, for example, 12345-6789. In 1967 the system of ZIP codes became obligatory in all territory of the USA. On July 1, 1963, the United States Postal Service implemented the ZIP (Zone Improvement Plan) Code to improve the sorting and delivery of mail and prepare the way for better, faster, automated processing of mailpieces. The character Mr. ZIP was designed to promote adoption of the new ZIP Code. The number of ZIP Code areas in use is constantly being revised. Currently there are over 42,000 ZIP Codes in use. The Official National Zone Charts identify the appropriate distance code assigned to each origin and destination ZIP Code pairing for every ZIP Code number in the nation. These distance codes, referred to as zones, are designated as 'Local' and '1 through 8'. Zone charts create a matrix for each originating ZIP Code number with the following (matched) information: 1)Destination ZIP Code range. 2)Associated zone for the distance. Zone charts are produced by the United States Postal Service using geological survey files of established latitude and longitude coordinates to determine the distance between origin and destination ZIP Code pairings. To calculate the zone chart based on the first 3 digits of any ZIP Code number you may use the Postal Zone Chart lookup tool (free of charge) at Zone Charts. Occasionally the United States Postal Service will add new or realign existing ZIP Code areas to accommodate population growth and operational needs. New ZIP Codes are announced publically by the District Office approximately thirty (30) days before the ZIP Code change goes into effect.