Introduce Zip Code Statement Of Work For Free

This is because ZIP code boundaries are based on mail routes and delivery points rather than geographic factors. The U.S. Post Office Department, predecessor to USPS, developed a zoning address system in 1943 as a way to make sorting and delivery of mail easier.

The check digit is calculated by adding up the digits of the zip code and seeing what would have to be added to the sum to get a multiple of 10. For example, the check digit for the zip code 51220 would be 0 (as 5 + 1 + 2 + 2 + 0 = 10), while the check digit for 82125 would be 2 (as 8 + 2 + 1 + 2 + 5 = 18).

The five-digit code which initially specified an area or a part of a town was no longer accurate or efficient enough. So, USPS created 9-digit ZIP Codes to ensure fast and accurate mailings.

The code became a tool for organizing and displaying demographic information while also allowing for the efficient sorting and dispatching of mail. Over the span of 50 years, the ZIP Code was expanded from 5 digits to 9 and then to 11, with each digit indicative of the address location.

These last 4 digits represent specific delivery routes within delivery areas. This extra detail means an even more precise matching to a more granular level. It could represent a handful of houses on one side of a street, or even a single building that receives a high volume of mail.

Primary state prefixes. ZIP Codes are numbered with the first digit representing a certain group of U.S. states, the second and third digits together representing a region in that group (or perhaps a large city) and the fourth and fifth digits representing a group of delivery addresses within that region.

ZIP Codes are numbered with the first digit representing a certain group of U.S. states, the second and third digits together representing a region in that group (or perhaps a large city) and the fourth and fifth digits representing a group of delivery addresses within that region.

?the five-digit ZIP number is a structured code in which the first digit identifies one of ten large areas of the Nation, and the second digit indicates a State, a geographic portion of a heavily populated State, or two or more less populated States.