| ZIP code | |
|---|---|
| Zone Improvement Plan | |
 The first digit of a United States ZIP code allocates it to a specific geographic zone. | |
| Status | Active |
| Year started | 1962 |
| Organization | United States Postal Service (USPS) |
| Authors | Robert Moon and the United States Post Office Department |
| Domain | Logistics, postal routing, and address verification |
| Website | usps.com |
The ZIP Code system (an acronym for Zone Improvement Plan) is the system of postal codes used by the United States Postal Service (USPS). The term ZIP was chosen to suggest that the mail travels more efficiently and quickly (zipping along) when senders include the code in the postal address. ZIP+4 is a registered trademark of the United States Postal Service, which also registered ZIP Code as a service mark until 1997, and which claims "ZIP Code" as a trademark though it is not registered.
Introduced on July 1, 1963, the basic format was five digits, the first designating a region of the country and subsequent digits localizing the destination further. In 1983, an extended code was introduced named ZIP+4; it included the five digits of the ZIP Code, followed by a hyphen and four digits that designated a location even more specific than the original five.
Private carriers and the USPS use ZIP Codes to route deliveries. In addition, ZIP Codes have become a basis for breaking down demographic, marketing, and sales data for analytical purposes.
A 1974 postage stamp encouraging people to use the ZIP Code on letters and parcels
John Smith
3256 Epiphenomenal Ave Apt 601
Minneapolis, MN 55416
In 1967, these became mandatory for second- and third-class bulk mailers, and the system was soon adopted generally. The United States Post Office used a cartoon character, which it called Mr. ZIP, to promote the use of the ZIP Code. The name "Mr. ZIP" was coined by D. Jamison Cain. Mr. ZIP was often depicted with a legend such as "USE ZIP CODE" in the selvage of panes of postage stamps or on the covers of booklet panes of stamps. Mr. ZIP was featured prominently alongside musical group "The Swingin' Six" in a variety show that the post office used to explain the importance of using ZIP Codes.
ZIP+4
editIn 1983, the U.S. Postal Service introduced an expanded ZIP Code system that it named ZIP+4, often known as "plus-four codes", "add-on codes", or "add-ons". A ZIP+4 Code uses the basic five-digit code plus four additional digits to identify a geographic segment within the five-digit delivery area, such as a city block, a group of apartments, an individual high-volume receiver of mail, a post office box, or any other unit that could use an extra identifier to aid in efficient mail sorting and delivery. However, the new format was not adopted universally by the public.
For example:
Furthermore, mail must be sorted in a specific manner to an 11-digit code with at least 150 mailpieces for each qualifying ZIP Code. It must be accompanied by documentation confirming this. These steps are usually done with PAVE-certified software that prints the barcoded address labels and the barcoded sack or tray tags.
Early advertisement for ZIP Code 10005
The second and third digits represent the sectional center facility (SCF) (e.g., 477xx = Vanderburgh County, Indiana). The fourth and fifth digits represent the area of the city (if in a metropolitan area), or a village/town (outside metro areas), e.g., 47722 (4=Indiana, 77=Vanderburgh County, 22=University of Evansville area). When a sectional center facility's area crosses state lines, it is assigned separate three-digit prefixes for the states it serves.
In some urban areas, like 462 for Marion County, Indiana, the three-digit prefix will often exist in one county, while, in rural and most suburban areas, the prefix will exist in multiple counties; for example, the neighboring 476 prefix is found in part or entirely in six counties: Gibson, Pike, Posey, Spencer, Vanderburgh, and Warrick. In some cases, an urban county may have more than one prefix. This is the case with Allen (467, 468), Lake (464, 463), St. Joseph (465, 466), and Vanderburgh (476, 477) counties. Cities like Chicago, Houston, Los Angeles, and New York City have multiple prefixes within their city limits. In some cases, these may be served from the same SCF, such as in San Diego County, California, where the three-digit prefixes 919 and 920 are used for suburban and rural communities, and 921 for the city of San Diego itself, although all three are processed through the same SCF.
JOHN ADAMS
UNIT 8400 BOX 0000
DPO AE
09498-0048
Division and reallocation
editLike area codes, ZIP Codes are sometimes divided and changed, especially when a rural area becomes suburban. Typically, the new codes become effective once announced, and a grace period (e.g., six months) is provided in which the new and old codes are used concurrently so that postal patrons in the affected area can notify correspondents, order new stationery, etc.
Opening a new sectional center facility is sometimes necessary in rapidly growing communities, which must then be allocated three-digit ZIP Code prefixes. Such allocation can be done in various ways. For example, when a new sectional center facility was opened at Dulles Airport in Virginia, the prefix 201 was allocated to that facility; therefore, for all post offices to be served by that sectional center facility the ZIP Code changed from an old code beginning with 220 or 221 to a new code or codes starting with 201. However, no new prefix was assigned when a new sectional center facility was opened to serve Montgomery County, Maryland. Instead, ZIP Codes in the 207 and 208 ranges, which had previously been assigned alphabetically, were reshuffled so that 207xx ZIP Codes in the county were changed to 208xx codes, while 208xx codes outside that county were changed to 207xx codes. Because Silver Spring (whose postal area includes Wheaton) has its own prefix, 209, there was no need to apply the reshuffling to Silver Spring; instead, all mail going to 209xx ZIP Codes was simply rerouted to the new sectional center facility.
On the other hand, depopulation may cause a post office to close and its associated ZIP Code to be deallocated. For example, Centralia, Pennsylvania's ZIP Code, 17927, was retired in 2002, and ZIP Codes for Onoville (14764), Quaker Bridge (14771) and Red House (14773) in New York were prevented from going into use in 1964 in preparation for the Kinzua Dam's completion.
Other uses
editDelivery services
editDelivery services other than the USPS, such as FedEx, United Parcel Service, and DHL, require a ZIP Code for optimal internal routing of a package.
Statistics
edit
ZIP Codes are regularly used on the Internet to provide a location where an exact address is not necessary (or desirable) but the user's municipality or general location is needed. Examples (in addition to the store locator example listed above) include weather forecasts, television listings, local news, and online dating (most general-purpose sites, by default, search within a specified radius of a given ZIP Code, based on other users' entered ZIP Codes).
Credit card security
editSee also
edit
- J. W. Westcott II – Mail boat and floating ZIP Code
- Postal codes in Canada
- ZIP codes in the Philippines