Examine individual changes

'{{About|postal codes in the United States and its associated states|postal codes in the Philippines|List of ZIP codes in the Philippines}} [[File:Mr. ZIP.png|thumb|[[Mr. ZIP]] promoted the use of ZIP codes for the USPS during the 1960s and 1970s.]] '''ZIP codes''' are a system of [[postal code]]s used by the [[United States Postal Service]] (USPS) since 1963. The term ''ZIP'', an acronym for '''Zone Improvement Plan''',<ref>{{cite web|title=Mr. Zip and the ZIP Code Promotional Campaign|url=http://www.postalmuseum.si.edu/zipcodecampaign/|publisher=Smithsonian National Postal Museum|accessdate=7 March 2013}}</ref> is properly written in capital letters and was chosen to suggest that the [[mail]] travels more efficiently, and therefore more quickly, when senders use the code in the [[Address (geography)|postal address]]. The basic format consists of five decimal [[numerical digit]]s. An extended '''ZIP+4''' code, introduced in the 1980s, includes the five digits of the ZIP code, a [[hyphen]], and four more digits that determine a more specific ___location within a given ZIP code. The term ''ZIP code'' was originally registered as a [[servicemark]] (a type of [[trademark]]) by the U.S. Postal Service, but its registration has since expired.<ref>{{cite web|url=http://tarr.uspto.gov/servlet/tarr?regser=serial&entry=73001312 |title=Latest Status Info |publisher=[[United States Patent and Trademark Office]] |accessdate=July 10, 2009}}</ref> ZIP codes designate only [[delivery point]]s within the United States and its dependencies, as well as locations of its armed forces. There are no ZIP codes reserved for designating mail bound for foreign destinations (with the exception of U.S. military units stationed outside of the United States), and therefore, international outbound mail should not include an American ZIP code in the delivery address (many overseas countries use postal codes and these can be included in a foreign address, usually after the name of the province, state or region). The last line of a foreign address must only show the name of the country of destination.<ref>{{cite web|url=http://pe.usps.gov/text/pub28/28apa_004.htm|title=International Addresses|publisher=[[United States Postal Service]] |accessdate=February 19, 2012}}</ref> ==Background== [[File:UseZipCode.JPG|thumb|A 1963 U.S. Post Office sign encouraging the use of ZIP codes]] [[File:Stamps USA, Markenheft IMG 1699.JPG|thumb|"Use Zip code" labels were also used to promote the use of a ZIP code.]] The [[United States Post Office Department]] (USPOD) implemented postal zones for large cities in 1943. For example: :Mr. John Smith :3256 Epiphenomenal Avenue :Minneapolis ''16'', Minnesota. The "16" was the number of the postal zone within the city. By the early 1960s a more organized system was needed, and on July 1, 1963, non-mandatory ZIP codes were announced for the entire country. Simultaneously with the introduction of the ZIP code, [[List of U.S. state abbreviations|two-letter state abbreviations]] were introduced. These are generally written with both letters capitalized. The reason for the two-letter abbreviations is that it was thought that a long city name coupled with a multi-letter state abbreviation (e.g. ''Mass.'' for Massachusetts; ''Ca.'', ''Cal.'', or ''Calif.'' for California; ''Pa.'', ''Penn.'', or ''Penna.'' for Pennsylvania) would be too long for address labels used on magazines when the ZIP code was added. [[Robert Moon (postal inspector)|Robert Moon]], an employee of the post office, is considered the father of the ZIP code; he submitted his proposal in 1944 while working as a [[United States Postal Inspection Service|postal inspector]].<ref>Tim Bullamore. [http://www.independent.co.uk/news/obituaries/robert-moon-729034.html Robert Moon Obituary]</ref> The post office gives credit to Moon for only the first three digits of the ZIP code, which describe the [[sectional center facility]] (SCF) or "sec center." An SCF is a central mail processing facility with those three digits. The SCF sorts mail to all post offices with those first three digits in their ZIP codes. The mail is sorted according to the final two digits of the ZIP code and sent to the corresponding post offices in the early morning. Sectional centers do not deliver mail and are not open to the public (though the building may include a post office open to the public), and most of the workers are employed to work [[shift work|night shift]]. Mail picked up at post offices is sent to their own SCF in the afternoon, where the mail is sorted overnight. In the cases of large cities, the last two digits coincided with the older postal zone number,{{citation needed|date=April 2010}} thus: :Mr. John Smith :3256 Epiphenomenal Avenue :Minneapolis, MN 554''16'' In 1967, these were made mandatory for second- and third-class [[bulk mail]]ers, and the system was soon adopted generally. The United States Post Office used a [[cartoon character]], whom it called [[Mr. ZIP]], to promote use of the ZIP code. He was often depicted with a legend such as "USE ZIP CODE" in the [[selvage]] of panes of [[Postage stamp|stamps]] or on labels contained in, or the covers of, booklet panes of stamps. ===ZIP+4=== In 1983, the U.S. Postal Service began using an expanded ZIP code system that it called ''ZIP+4'', often called "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 or any other unit that could use an extra identifier to aid in efficient mail sorting and delivery. But initial attempts to promote universal use of the new format met with public resistance,{{citation needed|date=April 2010}} and today the plus-four code is not required. In general, mail is read by a [[Multiline Optical Character Reader|multiline optical character reader]] (MLOCR) that almost instantly determines the correct ZIP+4 code from the address and—along with the even more specific [[delivery point]]—sprays a [[POSTNET|Postnet]] bar code on the face of the mail piece that corresponds to 11 digits—nine for the ZIP+4 code and two for the delivery point. For [[Post office box|Post Office Boxes]], the general (but not invariable) rule is that each box has its own ZIP+4 code. The add-on code is often one of the following: the last four digits of the box number (e.g., PO Box 727050, Defreestville NY 12144-7050), zero plus the last three digits of the box number (e.g., PO Box 17727, Eagle River, AK 99577-0727), or, if the box number consists of fewer than four digits, enough zeros are attached to the front of the box number to produce a four-digit number (e.g., PO Box 77, Juneau AK 99750-0077). However, there is no uniform rule, so the ZIP+4 code must be looked up individually for each box. It is common to use add-on code 9998 for mail addressed to the [[postmaster]] (to which requests for [[pictorial cancellation]]s are usually addressed), 9999 for [[poste restante|general delivery]] and other high-numbered add-on codes for [[freepost|business reply mail]].{{citation needed|date=April 2010}} For a unique ZIP code (explained below), the add-on code is typically 0001. ===Postal bar code=== [[File:Zip 5 postnet.png|200px|right|thumb|This is the address shown in the text with the [[POSTNET|Postnet]] [[bar code]] for the five-digit ZIP code '''55416'''.]] [[File:Zip plus 4.png|235px|right|thumb|This is the address shown in the text with the Postnet bar code for the nine-digit ZIP+4 code ''33701-'''4313'''''.]] The ZIP code is often translated into a [[barcode]] called [[POSTNET|Postnet]] that is printed on the mailpiece to make it easier for automated machines to sort. Unlike most barcode symbologies, Postnet uses long and short bars, not thin and thick bars. The barcode can be printed by the person who sends the mail (some word-processing programs such as [[WordPerfect]]<ref>{{cite web |url=http://kb.iu.edu/data/aapk.html |title=ARCHIVED: How can I print routing bar codes on envelopes? - Knowledge Base |publisher=The Trustees of Indiana University |accessdate=July 10, 2009}}</ref> and [[Microsoft Word]]<ref>{{cite web|url=http://office.microsoft.com/en-us/word/HA102103291033.aspx |title=Insert a barcode into an Office document |publisher=Microsoft Corporation |accessdate=July 10, 2009}}</ref> include the feature), or the post office will put one on when it processes the piece. In general, the post office uses [[Optical character recognition|OCR]] technology, though a human may have to read the address if absolutely necessary. People who send [[bulk mail]] can get a [[discounts and allowances|discount]] on [[postage]] if they have printed the barcode themselves. This requires more than just a simple [[typeface|font]]; [[mailing list]]s must be standardized with up-to-date [[Coding Accuracy Support System]] (CASS)-certified software that adds and verifies a full, correct ZIP+4 code and an additional two [[Numerical digit|digit]]s representing the exact [[delivery point]].{{citation needed|date=April 2010}} Furthermore, mail must be sorted in a specific scheme and be accompanied by documentation verifying this. These steps are usually done with PAVE-certified software that also prints the barcoded address labels and barcoded sack or tray tags. This means that every single mailable point in the country has its own 12-digit number (at least in theory). The delivery-point digits (the 10th and 11th digits) are calculated based on the primary or secondary number of the address. The USPS publishes the rules for calculating the delivery point in a document called the CASS Technical Guide.<ref>{{cite web |url=http://www.ribbs.usps.gov/files/CASS/TECHNICAL_GUIDES/CASSTECH.PDF#page=40 |format=PDF |title=CASS Technical Guide |publisher=United States Postal Service |pages=40 |year=2009–2010 cycle |accessdate=July 10, 2009}}</ref> However when confronted with two addresses like 18 and 18C often CASS will assign the same 12-digit number to two distinct mail delivery points. The last digit is ''always'' a [[check digit]], which is obtained by summing all 5, 9 or 11 digits, taking the [[modular arithmetic|residue]] modulo 10 of this sum (i.e., the remainder after dividing by 10) and finally [[subtract]]ing this from 10. (Thus, the check digit for 10001-0001 00 would be 7, since 1+1+1=3, 3≡3(mod 10) and 10–3=7.) An application needs only to print something like <code>/100010001007/</code> in the 12-[[Point (typography)|point]] Postnet font to create a valid barcode. The slashes "/" are translated into start/stop characters (one long bar), and each digit is translated into a sequence of [[two-out-of-five code|two long bars and three short bars]]. On business-reply mail, the [[Facing Identification Mark|FIM]] code primarily indicates the orientation (facing) of the mailpiece, since there is, in general, not a [[postage stamp|stamp]] or [[postage meter]] imprint containing fluorescent ink (which is usually used by the facing machine to orient mail).{{citation needed|date=April 2010}} Additionally, FIM codes A and C indicate that a Postnet bar code is present, allowing this mail to bypass the [[Multiline Optical Character Reader|MOCR]] and go straight to a barcode scanning machine.{{citation needed|date=April 2010}} For that reason, even though [[courtesy reply mail]] and [[metered reply mail]] are mailed with a stamp or a postage-meter imprint, they typically carry an FIM code, namely FIM A, to indicate that the Postnet bar code is present. The FIM D barcode is used for computer-generated indicia from online postage meters. ==Structure and allocation== ===By type/use=== [[File:USA-Stamp-1973-ZIPCode.jpg|thumb|right|120px|USA postage stamp, 1973: "It all depends on ZIP code".]] There are four types of ZIP codes: Unique (assigned to a single high-volume address), Post Office Box only (used only for PO Boxes at a given facility, not for any other type of delivery), Military (used to route mail for the U.S. military) and Standard (all other ZIP codes). As examples of Unique ZIP codes, certain governmental agencies, universities, businesses, or buildings that receive extremely high volumes of [[mail]] have their own ZIP codes, such as 20505 for the [[Central Intelligence Agency]] in [[Washington, D.C.]], 81009 for the [[Federal Citizen Information Center]] of the [[U.S. General Services Administration]] (GSA)<ref>{{cite web|url=http://www.pueblo.gsa.gov/aboutus.htm |title=FCIC&nbsp;&ndash; About Us |publisher=Federal Citizen Information Center of the U.S. General Services Administration |accessdate=July 10, 2009|quote=For years, consumers have written to Pueblo, Colorado 81009 for timely, practical information they trust.}}</ref> in [[Pueblo, Colorado]]; 30385 for [[BellSouth]] in [[Atlanta]]; 21412 for [[Bancroft Hall]], the midshipman dormitory at the [[United States Naval Academy]]; and 80841 for Sijan and Vendenberg Halls, the cadet dormitories at the [[United States Air Force Academy]]. Unique zip codes are not limited to government use -- Wal-Mart Stores, Inc., has a unique zip code (72716) while its facilities are surrounded by 72712 in Bentonville, AR and 72756 in Rogers, AR. <!-- NOTE: Please do not add more examples; these suffice. --> An example of a PO Box only ZIP code is 22313, which is used for PO Boxes at the main post office in [[Alexandria, Virginia]], as well as for the [[United States Patent and Trademark Office]]. In the area surrounding that post office, home and business mail delivery addresses use ZIP code 22314, which is thus a Standard ZIP code. ===By geography=== ====Primary State Prefixes==== ZIP codes are numbered with the first digit representing a certain group of [[U.S. state]]s, 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 main town in a region (if applicable) often gets the first ZIP codes for that region; afterward, the numerical order often follows the alphabetical order.{{citation needed|date=April 2010}} Because ZIP codes are intended for efficient postal delivery, there are unusual cases where a ZIP code crosses state boundaries, such as a military facility spanning multiple states or remote areas of one state most easily serviced from an adjacent state. For example ZIP code 42223 spans Christian, KY, and Montgomery, TN, and ZIP code 97635 spans Lake OR and Modoc CA. In general, the first three digits designate a [[sectional center facility (SCF)|sectional center facility]], the mail sorting and distribution center for an area. A sectional center facility may have more than one three-digit code assigned to it. For example, the Northern Virginia sectional center facility in Merrifield is assigned codes 220, 221, 222 and 223. In some cases, a sectional center facility may serve an area in an adjacent state, usually due to the lack of an appropriate ___location for a center in that region. For example, 739 in [[Oklahoma]] is assigned to [[Liberal, Kansas]]; 865 in [[Arizona]] is assigned to [[Gallup, New Mexico]]; and 961 in [[California]] to [[Reno, Nevada]]. In terms of geographic ___location, many of the lowest ZIP codes, which begin with&nbsp;'0', are in the [[New England]] region. Also in the '0' region are [[New Jersey]] (non-contiguous with the remainder of the '0' area), [[Puerto Rico]], the [[US Virgin Islands]] and [[APO/FPO]] military addresses for personnel stationed in [[Europe]], [[Africa]], [[Southwest Asia]] and aboard vessels based in the waters adjoining those lands; APO/FPO addresses are also used by U.S. diplomatic and consulary facilities. The lowest ZIP code is in [[Holtsville, New York]] (00501, a ZIP code exclusively for the [[U.S. Internal Revenue Service]] center there). Other low ZIP codes are 00601 for [[Adjuntas, Puerto Rico]]; 01001 for [[Agawam, Massachusetts]], and 01002 for [[Amherst, Massachusetts]]. Until 2001, there were six ZIP codes lower than 00501 that were numbered from 00210 to 00215 (located in [[Portsmouth, New Hampshire]]) and were used by the [[Diversity Immigrant Visa]] program to receive applications from non-U.S. citizens.{{citation needed|date=April 2010}} The numbers increase southward along the [[East Coast of the United States|East Coast]], such as 02115 ([[Boston]]), 10001 ([[New York City]]), 19103 ([[Philadelphia]]), 20008 ([[Washington, D.C.]]), 30303 ([[Atlanta]]) and 33130 ([[Miami]]) (these are only examples, as each of these cities contain several ZIP codes in the same range). From there, the numbers increase heading westward and northward east of the [[Mississippi River]], southward west of the Mississippi River, and northward on the [[West Coast of the United States|West Coast]], . For example, 40202 is in [[Louisville, Kentucky|Louisville]], 50309 in [[Des Moines, Iowa|Des Moines]], 60601 in [[Chicago]], 63101 in [[St. Louis]], 77063 in [[Houston]], 80202 in [[Denver]], 94111 in [[San Francisco]], 98101 in [[Seattle]], and 99950 in [[Ketchikan, Alaska]] (the highest ZIP code). [[File:ZIP Code zones.svg|thumb|right|400px|ZIP code zones in the USA]] The first digit of the ZIP code is allocated as follows: *'''0''' = [[Connecticut]] (CT), [[Massachusetts]] (MA), [[Maine]] (ME), [[New Hampshire]] (NH), [[New Jersey]] (NJ), [[Puerto Rico]] (PR), [[Rhode Island]] (RI), [[Vermont]] (VT), [[Virgin Islands]] (VI), Army Post Office Europe (AE), Fleet Post Office Europe (AE) *'''1''' = [[Delaware]] (DE), [[New York]] (NY), [[Pennsylvania]] (PA) *'''2''' = [[District of Columbia]] (DC), [[Maryland]] (MD), [[North Carolina]] (NC), [[South Carolina]] (SC), [[Virginia]] (VA), [[West Virginia]] (WV) * '''3''' = [[Alabama]] (AL), [[Florida]] (FL), [[Georgia (U.S. state)|Georgia]] (GA), [[Mississippi]] (MS), [[Tennessee]] (TN), Army Post Office Americas (AA), Fleet Post Office Americas (AA) * '''4''' = [[Indiana]] (IN), [[Kentucky]] (KY), [[Michigan]] (MI), [[Ohio]] (OH) * '''5''' = [[Iowa]] (IA), [[Minnesota]] (MN), [[Montana]] (MT), [[North Dakota]] (ND), [[South Dakota]] (SD), [[Wisconsin]] (WI) *''' 6''' = [[Illinois]] (IL), [[Kansas]] (KS), [[Missouri]] (MO), [[Nebraska]] (NE) * '''7''' = [[Arkansas]] (AR), [[Louisiana]] (LA), [[Oklahoma]] (OK), [[Texas]] (TX) * '''8''' = [[Arizona]] (AZ), [[Colorado]] (CO), [[Idaho]] (ID), [[New Mexico]] (NM), [[Nevada]] (NV), [[Utah]] (UT), [[Wyoming]] (WY) *''' 9''' = [[Alaska]] (AK), [[American Samoa]] (AS), [[California]] (CA), [[Guam]] (GU), [[Hawaii]] (HI), [[Marshall Islands]] (MH), [[Federated States of Micronesia]] (FM), [[Northern Mariana Islands]] (MP), [[Oregon]] (OR), [[Palau]] (PW), [[Washington (U.S. state)|Washington]] (WA), Army Post Office Pacific (AP), Fleet Post Office Pacific (AP) ====Secondary Regional Prefixes (123xx) and Local ZIP Codes (12345)==== {{see also|list of ZIP code prefixes}} [[File:10005_zip_code.jpg| thumb|Early advertisement for zip code 10005.]] The next two digits represent the [[Sectional center facility (SCF)|Sectional Center Facility (SCF)]] (e.g. 477xx = [[Vanderburgh County, Indiana]]), and the fourth and fifth digits represent the area of the city (if in a [[metropolitan area]]), or a village/town (outside metro areas): 47722 (4=Indiana, 77=Vanderburgh County, 22=[[University of Evansville]] area). When a sectional center facility's area crosses state lines, that facility is assigned separate three-digit prefixes for the states that 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 facility. {{Citation needed|date=December 2007}} Despite the geographic derivation of most ZIP codes, the codes themselves do not represent geographic regions; in general, they correspond to address groups or delivery routes. As a consequence, ZIP code "areas" can overlap, be subsets of each other, or be artificial constructs with no geographic area (such as 095 for mail to the Navy, which is not geographically fixed). In similar fashion, in areas without regular postal routes ([[Rural delivery service|rural route]] areas) or no mail delivery (undeveloped areas), ZIP codes are not assigned or are based on sparse delivery routes, and hence the boundary between ZIP code areas is undefined. For example, some residents in or near [[Haubstadt, Indiana]], which has the ZIP code 47639, have mailing addresses with 47648, the ZIP code for neighboring [[Fort Branch, Indiana]], while others living in or near Fort Branch have addresses with 47639. Many rural counties have similar logistical inconsistencies caused by the aforementioned sparse delivery routes, often known as Rural Routes or by some other similar designation. For example, almost all [[Federal government of the United States|U.S. government]] agencies in and around the capital are assigned ZIP codes starting with 20200 to 20599, which are [[Washington, D.C.]] ZIP codes, even if they are not located in Washington itself. While the [[White House]] itself is located in ZIP code 20006, it has the ZIP code 20500. The [[Nuclear Regulatory Commission]] is located in [[Rockville, Maryland]], at ZIP code 20852, but has been assigned by the Postal Service the address "Washington DC 20555". In similar manner, the ZIP code for the [[Metropolitan Washington Airports Authority]], a federally-chartered independent authority, is 20001-6000, even though the physical address of the Authority's office, "1 Aviation Circle",<ref>{{cite web|url=http://www.mwaa.com/866.htm|title=Contact Us |publisher=Metropolitan Washington Airports Authority |accessdate=September 26, 2010}}</ref> is in Arlington, Virginia.{{Citation needed|date=July 2009}} One current exception to this rule is the [[United States Patent and Trademark Office]] (USPTO). When the USPTO was located in the [[Arlington County, Virginia|Arlington, Virginia]] neighborhood of [[Crystal City, Arlington, Virginia|Crystal City]], it was assigned by the Postal Service the address "Washington, DC 20231" despite being physically located in ZIP code 22202. However, the USPTO now uses a ZIP code (22313-1450 in ZIP+4) assigned to its current physical ___location in [[Alexandria, Virginia]].<ref>{{cite web|url=http://www.uspto.gov/patents/mail.jsp |title=Mailing and Hand Carry Addresses for the United States Patent and Trademark Office |publisher=USPTO |accessdate=May 6, 2010}}</ref> In rare circumstances, a locality is assigned a ZIP code that does not match the rest of the state; in other words, a ZIP code may cross state lines. In general, the locality is so isolated that it is most conveniently served from a sectional center in another state. Examples: * [[Fishers Island]], New York, bears the ZIP code 06390 and is served from Connecticut because the only ferry service is to Connecticut&nbsp;– all other New York ZIP codes (excepting those at [[Holtsville, New York|Holtsville]] for the [[Internal Revenue Service|IRS]]) begin with "1". * Some Texas ZIP codes are served from New Mexico (most notably some [[El Paso, Texas|El Paso]] ZIP codes) and thus bear codes beginning with "885" (contiguous numerically with 870-884 NM) rather than "799". * Returned government parcels from [[Washington, D.C.]] are sent to ZIP codes beginning with "569", so that returned parcels are security checked at a remote facility (this was put into place after the [[2001 anthrax attacks]]). * Some Arkansas roads north of [[Bull Shoals Lake]] can best be accessed by the [[Protem, Missouri]], delivery unit (ZIP code 65733). * [[Fort Campbell]] (ZIP code 42223), primarily in Kentucky, main entrance is in Tennessee. * [[Cincinnati/Northern Kentucky International Airport]], despite being located across the [[Ohio River]] from Cincinnati in [[Hebron, Kentucky]], uses ZIP code 45275 for mailing only, due to the fact the [[Kenton County, Kentucky|Kenton County]] Airport Board, which owns and operates the airport, maintains a PO Box physically located at the main post office in [[Cincinnati]]. The physical address of the airport is 2939 Terminal Drive, Hebron, Kentucky, 41048. In essence the mail for the Kenton County Airport Board has an [[Ohio]] ZIP code but the physical address of the airport is a [[Kentucky]] ZIP code.<ref>[http://www.cvgairport.com/contact-us.aspx CVG | Contact Us<!-- Bot generated title -->]</ref> ====ZIP codes and previous zoning lines==== {{unreferenced-section|date=June 2013}} A ZIP code's address and the city name written on the same line do not necessarily mean that address is within that city. The Postal Service designates one ''preferred'' place name for each ZIP code. This may be an actual incorporated town or city, a subentity of a large city or an unincorporated [[census-designated place]], or a small [[unincorporated area|unincorporated community]]. Additional place names may be recognized as ''acceptable'' for a certain ZIP code. Still others are deemed not acceptable, and if used may result in a delay in mail delivery. ''Preferred'' place names are typically the actual city or town that the address is located in. However, for many cities that have incorporated since ZIP codes were introduced, the actual city name is not the ''preferred'' place name. Many databases automatically assign the ''preferred'' place name for a ZIP code, without regard to any ''acceptable'' place names. For example, [[Centennial, Colorado]] is divided among seven ZIP codes assigned to [[Aurora, Colorado|Aurora]], [[Englewood, Colorado|Englewood]] or [[Littleton, Colorado|Littleton]] as its ''preferred'' place names. Thus, from the perspective of the USPS, the city of Centennial does not exist—it is part of Aurora, Englewood or Littleton. In the ZIP-code directory, Centennial addresses are listed under those three cities. And since it is acceptable to write "Centennial" in conjunction with any of the seven ZIP codes, one can write "Centennial" in an address that is actually in Aurora, Englewood, or Littleton, as long as it is in one of the shared ZIP codes. ''Acceptable'' place names are usually added to a ZIP code in cases where the ZIP-code boundaries divide them between two or more cities, as in the case of Centennial. However, in many cases only the ''preferred'' name can be used, even when many addresses in the ZIP code are in another city. People sometimes must use the name of a post office rather than their own city. One extreme example is ZIP code 85254; it was assigned the place name [[Scottsdale, Arizona]] because it is served by the Scottsdale post office, but 85% of its territory is actually inside the city limits of neighboring [[Phoenix, Arizona|Phoenix]]. This may lead some residents of the ZIP code to mistakenly believe they live in Scottsdale when they actually live in Phoenix. Another notorious example is an entire neighborhood of the city of [[Los Angeles]] known as [[Beverly Hills Post Office]]. Naturally, its residents prefer the more glamorous [[Beverly Hills, California|Beverly Hills]] address and 90210 ZIP code, but this regularly causes problems with emergency response when dispatchers have to sort out whether a given home in 90210 actually sits in Los Angeles or Beverly Hills. Similarly, [[Missouri City, Texas]], straddles [[Harris County, Texas|Harris]] and [[Fort Bend County, Texas|Fort Bend]] counties. The portion within Harris County is within the ZIP code 77071, which must use the city name of [[Houston]] instead of Missouri City. At the same time, a small portion of the city of Houston is in Fort Bend County in the ZIP code 77489, and residents there must use the name ''Missouri City'' for their address even though they are in Houston. This also occurs in some rural areas where portions of one town have their mail delivered by other post offices. For example, while most of the town of [[Plainfield, Massachusetts]] is in ZIP code 01070, some sections of town are in the ZIP code area for the neighboring town of [[Cummington, Massachusetts|Cummington]] with ZIP code 01026. Only the ''preferred'' name of [[Cummington, Massachusetts|Cummington]] is allowed in ZIP code 01026, so residents of parts of [[Plainfield, Massachusetts|Plainfield]] must list their address as being in [[Cummington, Massachusetts|Cummington]]. These phenomena are repeated across the country. The previously mentioned [[Englewood, Colorado]] is an inner-ring suburb that was built out by the 1960s. Its post office served the area that is now the high-growth southern tier of the [[Denver-Aurora Metropolitan Area|Denver metropolitan area]], and ZIP codes in this area were assigned Englewood as their ''preferred'' place name. A business community as large as downtown [[Denver]] has grown in this area, with headquarters for many internationally recognized corporations. These companies indicate Englewood as their ___location (the ''preferred'' postal place name), although they are actually located in other cities. As a result, there are really two Englewoods&nbsp;– the actual city, small and with a largely [[Working class|working-class]] residential population, and, a number of miles away, the postal Englewood, a vast suburban area of upscale subdivisions and office parks that have nothing to do with the city of Englewood yet share a split identity with it solely because of ZIP codes. People who say they live or work in Englewood and identify closely with it may rarely enter the actual city. In [[Indiana]], the ZIP code for a town usually indicates the ZIP code for its corresponding township, as nearly all of Indiana's small town post offices have rural routes.{{citation needed|date=April 2010}} ''Acceptable'' place names also come into play in areas where citizens identify more strongly with a particular [[Urban Center|urban center]] than their own municipality. For example, [[Allegheny County, Pennsylvania]], has 130 distinct municipalities, yet many of the county's residents, and even some residents of adjacent counties, commonly use [[Pittsburgh|Pittsburgh, Pennsylvania]] as their postal address. On the opposite end of the spectrum, in some urban areas, neighborhood names may be acceptable even though they have no legal standing, such as [[La Jolla]], [[California]], which is the ''preferred'' place name for ZIP code 92037, despite the fact that La Jolla is a district of [[San Diego]], California and not a separate legal entity (this ZIP code is also in the 919/920 sequence used by San Diego County's suburban and rural areas, not in the 921 sequence used in the remainder of the City of San Diego, even though La Jolla has always been part of San Diego.) Many ZIP codes are for [[village]]s, [[census-designated place]]s, portions of cities, or other entities that are not municipalities. For example, ZIP code 03750 is for [[Etna, New Hampshire]], but Etna is not a city or town; it is actually a [[Village (United States)#New Hampshire|village district]] in the town of [[Hanover, New Hampshire|Hanover]], which itself is assigned the ZIP code 03755. Another example is ZIP code 08043, which corresponds to the census-designated place of [[Kirkwood, New Jersey]], but actually serves the entirety of [[Voorhees Township, New Jersey|Voorhees Township]]. This is also the case in [[LaGrange, New York]], a portion of which is served by the 12603 ZIP code based in the neighboring [[Poughkeepsie (town), New York|town of Poughkeepsie]]. The rest of LaGrange is served by the LaGrangeville Post Office. LaGrangeville is itself not a town at all, but a section of LaGrange. [[Willow Grove, Pennsylvania]], served by the 19090 ZIP code, is a village that straddles the border of [[Upper Moreland Township, Pennsylvania|Upper Moreland Township]] and [[Abington Township, Montgomery County, Pennsylvania|Abington Township]], and that post office also serves a small portion of [[Upper Dublin Township, Pennsylvania|Upper Dublin Township]]. Furthermore, non-municipal place names may also share ZIP codes with municipal place names. For example, [[West Windsor Township, New Jersey]], is commonly referred to in most mailing databases as [[Princeton Junction, New Jersey|Princeton Junction]], a census-designated place within West Windsor. Postal designations for place names become ''de facto'' locations for their addresses, and as a result it is difficult to convince residents and businesses that they actually are located in another city or town different from the ''preferred'' place name associated with their ZIP codes. Because of issues of confusion and lack of identity, some cities, such as [[Signal Hill, California]], have successfully petitioned the Postal Service to change ZIP-code boundaries or create new ZIP codes so their cities become the ''preferred'' place name for addresses within the ZIP code. Postal designation confusion may have financial implications for local governments, because mail volume is one factor used by the U.S. Census Bureau to estimate population changes between decennial census enumerations.{{citation needed|date=April 2010}} Sometimes local officials in a community that is not the ''preferred'' place name for a ZIP code but is an ''acceptable'' place name will advise residents to always use the name of the community, because if the census estimate of that town's population is low they may receive less funds that are computed based on population. A typical example is [[Paddock Lake, Wisconsin]], whose ''preferred'' place name is [[Salem, Kenosha County, Wisconsin|Salem]]. Paddock Lake is incorporated as a village within the town of Salem, even though there are more people in the village of Paddock Lake than there are in the unincorporated parts of the town of Salem. Further confusion is caused because [[Silver Lake, Wisconsin]], which is also a village in the town of Salem and is of similar size and status to Paddock Lake, has its own ZIP code and post office. In another case, the U.S. [[Federal Communications Commission]] (FCC) denied a [[radio station]] (now [[WNNX (FM)|WNNX]] FM) a move requiring a change in its [[city of license]] to [[Sandy Springs, Georgia|Sandy Springs]], [[Georgia (U.S. state)|Georgia]], largely because it was not a city (until [[municipal incorporation]] in late 2005), despite being the seventh-largest place in the state by [[population]]. The FCC cited the use of "[[Atlanta]]" on letters of support from local organizations, even though the USPS forced them to use Atlanta for 30328 until well after incorporation took effect. Currently "Sandy Springs" is only ''acceptable'', despite none of 30328 being in Atlanta, or anywhere else outside the Sandy Springs [[city limit]]. This even applies to the ZIP code used only for PO boxes at the Sandy Springs main post office. Because ZIP codes and their associated place names can ignore county lines, problems may occur where [[street address]]es are based on [[Address (geography)#Quadrants|quadrant]] ___location within a county. For example, 30339 spans over [[Vinings, Georgia]] and [[Atlanta, Georgia]], in southeastern [[Cobb County, Georgia|Cobb County]]; therefore every street address is labeled SE, and has a [[house number]] on that county's grid (according to the distance from the [[town square]] in the [[county seat]]). However, because the USPS demands the use of Atlanta, Vinings addresses are written such that they appear to be in southeast Atlanta, instead of on the opposite (northwest [[metro Atlanta]]) side where they actually are. ====Division and reallocation of ZIP codes==== Like [[area code]]s, ZIP codes are sometimes divided and changed, especially when a [[rural]] area becomes [[suburb]]an. Typically, the new codes become effective once announced, and a grace period (e.g., one year) 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.<ref>{{cite news |first=Sam |last=Roberts |url=http://www.nytimes.com/2007/03/21/nyregion/21zip.html |title=An Elite ZIP Code Becomes Harder to Crack |work=[[The New York Times]] |date=March 21, 2007 |page= C15 |accessdate=July 10, 2009}}</ref> In rapidly growing communities, it is sometimes necessary to open a new sectional center facility, which must then be allocated its own three-digit ZIP-code prefix or prefixes. Such allocation can be done in various ways. For example, when a new sectional center facility was opened at [[Washington Dulles International Airport|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 beginning with 201. However, when a new sectional center facility was opened to serve [[Montgomery County, Maryland]], no new prefix was assigned. 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, Maryland|Silver Spring]] (whose postal area includes [[Wheaton, Maryland|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.<ref>{{cite news |first=Rob |last=Wheary |url=http://www.centraliapa.com/news.htm |title=Centralia loses its ZIP}}</ref> [[Elkins Park, Pennsylvania]], was originally issued the 19117 ZIP code, although it lies in [[Montgomery County, Pennsylvania|Montgomery County]]. Because of the 191 prefix, which is found only in [[Philadelphia]] with that lone exception, auto insurance companies charged higher city premiums to that suburban ___location. For that reason, residents petitioned the USPS for a 190-prefix ZIP code, which is common to the inner-ring Pennsylvania suburbs of that city, and, after several attempts that were initially disapproved by the USPS, Elkins Park was finally reassigned to the 19027 ZIP code. ZIP codes also change when postal boundaries are realigned. For example, at the same time at which the above-noted change in Montgomery County took place, and under pressure from then-mayor of [[Washington, D.C.]], [[Marion Barry]], the USPS realigned the postal boundaries between Washington, D.C. and [[Maryland]] to match the actual boundary. Previously, many inner suburbs, such as [[Bethesda, Maryland|Bethesda]] and [[Takoma Park, Maryland|Takoma Park]], had been in the Washington, D.C., postal area. As a result of the change, ZIP codes in Maryland beginning with 200 were changed to new ZIP codes beginning with 207, 208 or 209, depending on their ___location, and ZIP codes straddling the D.C.-Maryland line were split. For example, 20014 (Bethesda) became 20814, while the Maryland portion of 20012 (Takoma Park) became 20912. ==Other uses== ===Delivery services=== Delivery services other than the USPS, such as [[FedEx]], [[United Parcel Service]] and [[DHL Express|DHL]] require a ZIP code for optimal internal routing of a package. ===Statistics=== There are over 42,000 ZIP Codes in the United States.<ref>{{cite web|url=http://faq.usps.com/eCustomer/iq/usps/request.do?session={84f59920-8889-11e0-4299-000000000000}&event=1&view=c{09e32160-9733-11de-f432-000000000000}&objectId=&eksObjectId=&objectType=Case&isJumpEnabled=false&isContentJumpEnabled=false&vendorKey=&objTitle=&versionId=6482&searchProperties=undefined&naturalAdvance=false&allStr=&phraseStr=&anyStr=&noneStr=&keywordStr=&tTitle=&topicFromSub=&topicsORSubUrl=&report(0000)=p{aefc0190-28a9-11e0-5c1d-000000000000}&bcobjectId={2adbb220-28a9-11e0-5c1d-000000000000}&search=zip%20code&topicAndSubtopic=Customer%20Service$ALL |title=United States Postal Service FAQs |publisher=USPS |accessdate=May 27, 2011}}</ref> ZIP codes are used not only for tracking of mail but also in gathering geographical statistics in the United States. The [[United States Census Bureau|U.S. Census Bureau]] calculates approximate boundaries of ZIP Codes areas, which it calls [[ZIP Code Tabulation Area]]s (ZCTAs). Statistical census data is then provided for these approximate areas. The geographic data provided for these areas includes the [[latitude]] and [[longitude]] of the center-point of the [[ZIP Code Tabulation Area|ZCTAs]]. There are approximately 32,000 ZCTAs. The reason that there is not one ZCTA for every ZIP Code is that PO Boxes are excluded, since only populated areas are included in the Census data.<ref>{{cite web|title=U.S. Census Bureau data provided by GreatData.com|url=http://greatdata.com|accessdate=5 February 2013}}</ref> The Census Bureau provides many statistical data sets for ZIP Codes, but does not keep up-to-date datasets of all [[ZIP Code Tabulation Area|ZCTAs]]. Complete datasets providing a similar approximate geographic extent are commercially available. ZIP Codes are inherently discrete data, or point based data, as they are assigned only at the point of delivery, not the spaces in between the delivery points. The [[United States Census Bureau|U.S. Census Bureau]] then interpolates this discrete data set to create polygons, or areal features representing the approximate extent of the ZIP Code to use for mapping and data presentation. [[ZIP Code Tabulation Area|ZCTAs]] are not to be confused with ZIP codes, and they are not updated as frequently as ZIP Codes. However for many research and planning purposes they are very useful, and can be used with ZIP Code data. ===Marketing=== The data is often used in [[advertising mail|direct mail marketing]] campaigns in a process called [[ZIP Code marketing|ZIP-code marketing]]. [[Point of Sale|Point-of-sale]] cashiers sometimes ask consumers their home ZIP code. Besides providing purchasing-pattern data useful in determining the ___location of new business establishments, retailers can use directories to correlate this ZIP code with the name on a credit card to obtain a consumer's full address and [[telephone number]]. ZIP-coded data are also used in analyzing geographic factors in risk, an [[insurance]]-[[industry]] and [[banking]] practice [[pejorative]]ly known as [[redlining]]. This can cause problems (e.g. expensive insurance) for people living near a town with a high crime rate and sharing its ZIP code, while they themselves actually live in a relatively crime-free town (see Elkins Park, Pennsylvania, above.) According to an online [[CNN]] news story by [[Greg Botelho]] posted on Thursday, February 10, 2011, "California's high court ruled Thursday that retailers do not have the right to ask customers for their ZIP code while completing credit card transactions, saying that doing so violates a cardholders' right to protect his or her personal information."<ref>{{cite news | title=California high court: Retailers can't request cardholders' ZIP code | url=http://www.cnn.com/2011/US/02/10/california.credit.zip.code/index.html | last=Botelho | first=Greg | publisher=[[CNN]] | date=February 10, 2011 | accessdate=February 11, 2011}}</ref> ===Legislative districts=== ZIP codes can be used to identify legislative districts. For example, the website of the [[U.S. House of Representatives]] has a "Find Your Representative" feature in the upper left corner based on ZIP code. ===Internet=== A 1978 proposal for a nationwide system of [[community network]]s proposed using ZIP codes for [[routing]].<ref name="wilber197802">{{cite news | url=http://archive.org/stream/byte-magazine-1978-02/1978_02_BYTE_03-02_Hardware_Projects#page/n15/mode/2up | title=CIE Net: A Design for a Network of Community Information Exchanges | work=BYTE | date=February 1978 | accessdate=17 October 2013 | author=Wilber, Mike | pages=12}}</ref> ZIP code data is an integral part of dealer/[[store locator]] software on many [[web sites]], especially [[bricks and clicks|brick-and-click]] websites. This software processes a user-input ZIP code and returns a list of store or business locations, usually in order of increasing distance from the center of the input ZIP code. As the ZIP system is confined to the U.S. Postal network, websites that require ZIP codes cannot register customers outside the U.S. Many sites will either purchase postal code data of other countries, or make allowances in cases where the ZIP Code isn't recognized. ZIP codes can also be used to pull-up local news data embedded on news websites of national networks, as well as weather information. Similarly, local TV listings (including show times on syndicated programs) can be accessed by inputting the ZIP code. ===Credit card security=== {{Main|Address Verification System}} ZIP codes are used in credit card authorization, specifically [[Address Verification System]] (AVS). When a merchant collects the entire address, the ZIP code is an important part of AVS. In some cases, the ZIP code is the only thing used for AVS, specifically where collecting a signature, or other information is infeasible, such as [[pay at the pump]], [[Redbox]] terminals, or [[vending machines]]. ===Insurance Rating=== ZIP Codes are used by most insurance carriers to determine the rate the customer will receive. Higher populated areas will generally receive a higher rate, but that is not always true. In some areas with a high population, the rate for comprehensive coverage can be lower due to the fact that the area has a low crime rate. ==See also== * [[J. W. Westcott II]] * [[List of ZIP code prefixes]] * [[Postal code]] * [[ZIP Code Tabulation Area]] {{Americas topic|Postal codes in}} ==References== {{Reflist|30em}} ==External links== *[http://www.uszipcodes.com/ Good, concise history of the ZIP Code, plus links to Free ZIP Code Lookup Tools.] {{DEFAULTSORT:Zip Code}} [[Category:ZIP code| ]] [[Category:1963 introductions]] [[Category:Postal codes by country]] [[Category:Philatelic terminology]] [[Category:1963 in the United States]]'