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ZIP Code



 
 
The ZIP code is the system of postal code
Postal code

A postal code is a series of letters and/or numerical digits appended to a address for the purpose of sorting mail.Germany was the first country to introduce a postal code system, in 1941....
s used by the United States Postal Service
United States Postal Service

The United States Postal Service is an Independent agencies of the United States government responsible for providing postal service in the United States....
 (USPS). The letters ZIP, an acronym for Zone Improvement Plan, are properly written in capital letters and were chosen to suggest that the mail
Mail

Mail, or post, is a method for transmitting information and tangible objects, wherein written documents, typically enclosed in envelopes, and also small packages, are delivered to destinations around the world....
 travels more efficiently, and therefore more quickly, when senders use the code. The basic format consists of five numerical digit
Numerical digit

In mathematics and computer science, a digit is a symbol used in numerals , to represent numbers, in Positional notation numeral systems. The name "digit" comes from the fact that the 10 digits of the hands correspond to the 10 symbols of the common base 10 number system, i.e....
s. An extended ZIP + 4 code includes the five digits of the ZIP code, a hyphen
Hyphen

A hyphen is a punctuation mark. It is used both to join words and also to separate syllables of a single word. It is often confused with the dash , which are longer and have different uses, and with the minus sign which is also longer....
, and four more digits that determine a more precise location than the ZIP code alone.






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Encyclopedia


The ZIP code is the system of postal code
Postal code

A postal code is a series of letters and/or numerical digits appended to a address for the purpose of sorting mail.Germany was the first country to introduce a postal code system, in 1941....
s used by the United States Postal Service
United States Postal Service

The United States Postal Service is an Independent agencies of the United States government responsible for providing postal service in the United States....
 (USPS). The letters ZIP, an acronym for Zone Improvement Plan, are properly written in capital letters and were chosen to suggest that the mail
Mail

Mail, or post, is a method for transmitting information and tangible objects, wherein written documents, typically enclosed in envelopes, and also small packages, are delivered to destinations around the world....
 travels more efficiently, and therefore more quickly, when senders use the code. The basic format consists of five numerical digit
Numerical digit

In mathematics and computer science, a digit is a symbol used in numerals , to represent numbers, in Positional notation numeral systems. The name "digit" comes from the fact that the 10 digits of the hands correspond to the 10 symbols of the common base 10 number system, i.e....
s. An extended ZIP + 4 code includes the five digits of the ZIP code, a hyphen
Hyphen

A hyphen is a punctuation mark. It is used both to join words and also to separate syllables of a single word. It is often confused with the dash , which are longer and have different uses, and with the minus sign which is also longer....
, and four more digits that determine a more precise location than the ZIP code alone. The term ZIP Code was originally registered as a servicemark (a type of trademark
TradeMark

TradeMark is a tall, primarily residential, skyscraper in Charlotte, North Carolina. It was completed in 2007 and has 28 floors. There are 200 hundred residential units....
) by the U.S. Postal Service, but its registration has since expired.

Background

The United States Post Office Department
United States Post Office Department

The Post Office Department is the former name of the United States Postal Service when it was a United States Cabinet department. It was headed by the United States Postmaster General....
 (USPOD) implemented postal zones for large cities in 1943. For example:

Mr. John Smith
3256 Epiphenomenal Avenue
Minneapolis 16, Minnesota


The "16" is the number of the postal zone within the city.

By the early 1960s a more general system was needed, and on July 1, 1963, non-mandatory ZIP codes were announced for the whole country. Robert Moon
Robert Moon (postal inspector)

Robert Aurand Moon , sometimes called 'Mr. ZIP', is considered the father of the ZIP Code or Zone Improvement Plan, a mechanism to route mail in the United States....
, an employee of the post office, is considered the father of the ZIP code. He submitted his proposal in 1944 while working as a postal inspector.

The post office only gives credit to Moon for the first three digits of the ZIP code, which describe the sectional center facility, or SCF, also called "sec center." An SCF is a central mail processing facility with those 3 digits. The SCF sorts mail to all post offices with those first 3 digits in their ZIP codes. The mail is sorted according to the final 2 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 during the overnight. 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, thus:

Mr. John Smith
3256 Epiphenomenal Avenue
Minneapolis, Minnesota 55416


In 1967, these were made mandatory for second- and third-class bulk mail
Bulk mail

Bulk mail broadly refers to mail that is mailed and processed in bulk at reduced rates. The term does not denotation any particular purpose for the mail; in particular, it is not synonymous with "junk mail."...
ers, and the system was soon adopted generally. The United States Post Office used a cartoon character, Mr. ZIP
Mr. ZIP

File:UseZipCode.JPGMr. ZIP, informally "Zippy", is a cartoon character used in the 1960s by the United States Post Office Department, and in the 1970s by its successor, the United States Postal Service, to encourage the general public to include the ZIP code in all mailings....
, to promote use of the ZIP code. He was often depicted with a legend such as "USE ZIP CODES" in the selvage
Selvage

In a weaving fabric, the selvage is the uncut edge of the fabric which is on the right- and left-hand edges as it comes out of the loom. As such it is 'finished' and will not fray because the weft threads double back on themselves....
 of panes of stamp
Postage stamp

A postage stamp is adhesive paper evidence of a fee paid for Mail services. Usually a small rectangle attached to an envelope, the stamp signifies the person sending it has fully or partly paid for delivery....
s or on labels contained in, or the covers of, booklet panes of stamps. Curiously enough, the only time the Postal Service issued a stamp promoting the ZIP code, in 1974, Mr. ZIP was not depicted.

ZIP + 4

In 1983, the U.S. Postal Service began using an expanded ZIP code system called "ZIP + 4", often called "plus-four codes" or "add-on codes" or "add ons." The Postal Service has a "Find a ZIP Code" feature on its , which provides an address format that is most compatible with its optical character recognition
Optical character recognition

Optical character recognition, usually abbreviated to OCR, is the mechanical or Electronics translation of s of handwritten, typewritten or printed text into machine-editable text....
 (OCR), scanners:

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. Initial attempts to promote universal use of the new format met with public resistance, and today the plus-four code is not required. In general, mail is read by a multiline optical character reader
Multiline Optical Character Reader

A Multiline Optical Character Reader, or MLOCR, is a type of mail sorting machine that uses Optical Character Recognition technology to determine how to route mail through the postal system....
 (MLOCR) that almost instantly determines the correct ZIP + 4 code from the address and—along with the even more specific delivery point
Delivery point

In a Mail system, a delivery point is a single mailbox or other place at which mail is delivered. It differs from a address , in that each address may in fact have several delivery points, such as an apartment flat, office Departmentalization, or other room ....
—sprays a Postnet
POSTNET

POSTNET is a barcode symbology that is used by the United States Postal Service to assist in directing mail. The ZIP Code or ZIP+4 code is encoded in half- and full-height bars....
 barcode on the face of the mailpiece that corresponds to 11 digits. This technology has greatly increased the speed and accuracy of mail delivery and kept costs nearly constant for over a decade.

For post-office box
Post Office box

A post office box is a uniquely-addressable lockable box located on the premises of a post office station.In many countries, particularly in Africa, and the Middle East there is no 'door to door' delivery of mail....
es, 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 58001, Washington DC 20037-8001), zero plus the last three digits of the box number (e.g., PO Box 12344, Chicago IL 60612-0344), or, if the box number consists of fewer than four digits, enough zeros prepended to the front of the box number to produce a four-digit number (e.g., PO Box 52, Garrett Park MD 20896-0052). 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 cancellations are usually addressed), 9999 for general delivery
Poste restante

Poste restante is a service where the post office holds mail until the recipient calls for it. It is a common destination for mail for people who are visiting a particular location and have no need, or no way, of having mail delivered directly to their place of residence at that time....
 and other high-numbered add-on codes for business reply mail
Freepost

Freepost is a postal service provided by various postal administrations, whereby a person sends mail without affixing postage, and the recipient pays the postage when collecting the mail....
. For a unique ZIP code (explained below), the add-on code is typically 0001.

Postal bar code

Zip 5 Postnet
Zip Plus 4
The ZIP code is often translated into a barcode
Barcode

A bar code is an optical machine-readable representation of data. Originally, bar codes represented data in the widths and the spacings of parallel lines and may be referred to as linear or 1D barcodes or symbologies....
 called Postnet
POSTNET

POSTNET is a barcode symbology that is used by the United States Postal Service to assist in directing mail. The ZIP Code or ZIP+4 code is encoded in half- and full-height bars....
 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
WordPerfect

WordPerfect is a proprietary software word processing application, now owned by Corel. Bruce Bastian, a Brigham Young University graduate student and BYU computer science professor Dr....
 and pre-2007 versions of Microsoft Word
Microsoft Word

Microsoft Word is Microsoft's word processor computer software. It was first released in 1983 under the name Multi-Tool Word for Xenix systems....
 include the feature), or the post office will put one on when it processes the piece. The post office generally uses OCR
Optical character recognition

Optical character recognition, usually abbreviated to OCR, is the mechanical or Electronics translation of s of handwritten, typewritten or printed text into machine-editable text....
 technology, though a human may have to read the address if absolutely necessary. (The automated machinery has the unfortunate tendency to paste the coding over the bottom half-inch of postcard
Postcard

A postcard or post card is a rectangular piece of thick paper or thin Card stock intended for writing and mailing without an envelope and at a lower rate than a letter ....
s, often obliterating the signature. Postcard printers have begun blocking a section off where the barcode will be placed.)

People who send bulk mail
Bulk mail

Bulk mail broadly refers to mail that is mailed and processed in bulk at reduced rates. The term does not denotation any particular purpose for the mail; in particular, it is not synonymous with "junk mail."...
 can get a discount
Discount

A "Discount" is a "Charge" that is paid to obtain the right to delay a payment. Essentially, the payer purchases the right to make a given payment in the future instead of in the Present....
 on postage if they have pre-printed the barcode themselves. This requires more than just a simple font
Typeface

In typography, a typeface is a set of one or more fonts, in one or more sizes, designed with stylistic unity, each comprising a coordinated set of glyphs....
; mailing lists must be standardized with up-to-date CASS
Cass

Cass may refer to:...
 certified software that adds and verifies a full, correct ZIP + 4 code and an additional two digit
Numerical digit

In mathematics and computer science, a digit is a symbol used in numerals , to represent numbers, in Positional notation numeral systems. The name "digit" comes from the fact that the 10 digits of the hands correspond to the 10 symbols of the common base 10 number system, i.e....
s representing the exact delivery point
Delivery point

In a Mail system, a delivery point is a single mailbox or other place at which mail is delivered. It differs from a address , in that each address may in fact have several delivery points, such as an apartment flat, office Departmentalization, or other room ....
. Furthermore, mail must be presorted 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. The last digit is always a check digit
Check digit

A check digit is a form of redundancy check used for error detection, the decimal equivalent of a binary checksum. It consists of a single digit computed from the other digits in the message....
, which is obtained by summing all 5, 9 or 11 digits, taking the residue
Modular arithmetic

In mathematics, modular arithmetic is a system of arithmetic for integers, where numbers "wrap around" after they reach a certain value — the modulus....
 modulo 10 of this sum (i.e., the remainder after dividing by 10) and finally subtracting this from 10. (Thus, the check digit for 10001-0001 00 would be 7, since 1+1+1=3, 3%10=3 and 10-3=7.) An application needs only to print something like /100010001007/ in the 12-point
Point (typography)

In typography, a point is the smallest Typographic unit of measure, being a subdivision of the larger Pica . It is commonly abbreviated as pt. The traditional printer's point, from the era of hot metal typesetting and Printing press, varied between 0.18 and 0.4 Milimeter depending on various definitions of the foot....
 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 long bars and three short bars
Two-out-of-five code

In telecommunication, a two-out-of-five code is an m of n codes that provides exactly ten possible combinations, and thus is popular for representing decimal digits using five bits....
.

On business-reply mail, the FIM
Facing Identification Mark

The Facing Identification Mark, or FIM, is a bar code designed by the United States Postal Service to assist in the automated processing of mail....
 code primarily indicates the orientation (facing) of the mailpiece, since there is generally not a stamp
Postage stamp

A postage stamp is adhesive paper evidence of a fee paid for Mail services. Usually a small rectangle attached to an envelope, the stamp signifies the person sending it has fully or partly paid for delivery....
 or postage meter
Postage meter

A postage meter is an mechanical device used to create and apply physical evidence of postage to mailed matter. Postage meters are regulated by a country's postal authority; for example, in the United States, the United States Postal Service specifies the rules for the creation, support, and use of postage meters....
 imprint containing fluorescent ink (which is usually used by the facing machine to orient mail.) Additionally, FIM codes A and C indicate that a Postnet bar code is present, allowing this mail to bypass the MOCR
Multiline Optical Character Reader

A Multiline Optical Character Reader, or MLOCR, is a type of mail sorting machine that uses Optical Character Recognition technology to determine how to route mail through the postal system....
 and go straight to a barcode scanning machine. For that reason, even though courtesy reply mail
Courtesy reply mail

Courtesy reply mail, or CRM, is a type of mail in which a business sends pre-printed, self-addressed envelopes or postcards to customers, who then affix postage stamps to the envelopes or postcards and mail them back to the business....
 and metered reply mail
Metered reply mail

Metered reply mail, or MRM, is a type of mail in which a business sends pre-printed, self-addressed envelopes or postcards to customers, with postage prepaid on the envelopes or postcards with a postage meter....
 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 geography


ZIP codes are numbered with the first digit representing a certain group of U.S. state
U.S. state

A U.S. state is any one of the 50 state of the United States that share sovereignty with the federal government of the United States . Because of this shared sovereignty, an United States is a citizen both of the federal entity and of his or her state of Domicile ....
s, the second and third digits together representing a region
Region

Region is a geographical term that is used in various ways among the different branches of geography. In general, a region is a medium-scale area of land or water, smaller than the whole areas of interest , and larger than a specific site A region may be seen as a collection of smaller units or as one part of a larger whole ....
 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. 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 (q.v.).

Generally, the first three digits designate a sectional center facility
Sectional center facility (SCF)

A Destination Sectional Center Facility is a Processing and Distribution Center of the United States Postal Service that serves a designated geographical area defined by one or more three-digit ZIP Code prefixes....
, 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
Oklahoma

Oklahoma is a U.S. state and a sovereignty located in the South Central United States and Southern United States of the United States of America ....
 is assigned to Liberal, Kansas
Liberal, Kansas

Liberal is a city in Seward County, Kansas, Kansas, United States. The population was 19,666 at the United States Census 2000. It is the county seat of Seward County, Kansas....
; 865 in Arizona
Arizona

The State of Arizona is a U.S. state located in the Southwestern United States of the United States. The capital and largest city is Phoenix, Arizona....
 is assigned to Gallup, New Mexico
Gallup, New Mexico

Gallup is a city in McKinley County, New Mexico, New Mexico, United States. The population was 20,209 at the 2000 United States Census. It is the county seat of McKinley County, New Mexico....
; and 961 in California
California

California is a U.S. state on the West Coast of the United States of the United States, along the Pacific Ocean. It is bordered by Oregon to the north, Nevada to the east, Arizona to the southeast, and to the south the Mexico state of Baja California....
 to Reno, Nevada
Reno, Nevada

Reno is the county seat of Washoe County, Nevada, Nevada, United States. A 2006 estimate indicated that the city's population had increased to 214,853, but ranked Reno as the third largest city in the state following Las Vegas, Nevada, and Henderson, Nevada....
.

Geographically, many of the lowest ZIP codes are in the New England
New England

New England is a region of the United States located in the northeastern corner of the country, bounded by the Atlantic Ocean, Canada and New York State, and consisting of the modern U.S....
 region, since these begin with '0'. Also in the '0' region are New Jersey
New Jersey

New Jersey is a state in the Mid-Atlantic States and Northeastern United States regions of the United States. It is bordered on the north by New York, on the east by the Hudson River and the Atlantic Ocean, on the southwest by Delaware, and on the west by Pennsylvania....
 (non-contiguous with the remainder of the '0' area), Puerto Rico
Puerto Rico

Puerto Rico , officially the Commonwealth of Puerto Rico , is a Autonomy Territories of the United States of the United States located in the northeastern Caribbean, east of the Dominican Republic and west of the Virgin Islands....
, the U.S. Virgin Islands and APO/FPO military addresses for personnel stationed in Europe
Europe

Europe is, conventionally, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally divided from Asia to its east by the water divide of the Ural Mountains, the Ural , the Caspian Sea, and by the Caucasus Mountains to the southeast....
, Africa
Africa

Africa is the world's second-largest and second most-populous continent, after Asia. At about 30.2 million km? including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area....
, Southwest Asia
Southwest Asia

Southwest Asia or Southwestern Asia is the southwestern subregion of Asia. The term West Asia is sometimes used in the United Nations subregion geoscheme and in writings about the archeology and the late prehistory of the region....
 and aboard vessels based in the waters ajoining those lands; APO/FPO addresses are also used by U.S. diplomatic and consulary facilities. The lowest ZIP code is in Holtsville, New York
Holtsville, New York

Holtsville is a hamlet in Suffolk County, New York, New York, United States. The population was 17,006 at the 2000 census.Holtsville is the location of an Internal Revenue Service Processing Center and is in the Brookhaven, New York and the Town of Islip....
 (00501, a ZIP Code exclusively for the U.S. Internal Revenue Service center there). Other low ZIP codes are 00601 for Adjuntas, Puerto Rico
Adjuntas, Puerto Rico

Adjuntas , is a small mountainside Municipalities of Puerto Rico in Puerto Rico located central midwest of the island on the Cordillera Central, Puerto Rico , north of Yauco, Puerto Rico, Guayanilla, Puerto Rico and Pe?uelas, Puerto Rico; southeast of Utuado, Puerto Rico; east of Lares, Puerto Rico and Yauco; and west of Ponce, Puerto Rico....
; 01001 for Agawam, Massachusetts
Agawam, Massachusetts

The Town of Agawam is a city in Hampden County, Massachusetts, Massachusetts, United States. The population was 28,144 at the 2000 census. Agawam is part of the Springfield, Massachusetts Springfield, Massachusetts metropolitan area and contains a subsection, Feeding Hills....
, and 01002 for Amherst, Massachusetts
Amherst, Massachusetts

Amherst is a New England town in Hampshire County, Massachusetts, Massachusetts, United States in the Connecticut River valley. As of the 2000 census, the population was 34,874....
. Until 2001 there were six ZIP codes lower than 00501 that were numbered from 00210 to 00215 (located in Portsmouth, New Hampshire
Portsmouth, New Hampshire

Portsmouth is a city in Rockingham County, New Hampshire, New Hampshire in the United States. It is the fourth-largest community in the county, with a population of 20,784 at the United States Census, 2000....
) and were used by the Diversity Immigrant Visa
Diversity Immigrant Visa

The Diversity Immigrant Visa program is a United States congressionally mandated lottery program for receiving a United States Permanent Resident Card....
 program to receive applications from non-U.S. citizens.

The numbers increase southward along the East Coast, such as 02115 (Boston
Boston, Massachusetts

Boston is the State capital and largest city of the Commonwealth of Massachusetts, and is one of the oldest cities in the United States. The largest city in New England, Boston is considered the economic and cultural center of the region, and is sometimes regarded as the unofficial "Capital of New England." Boston city proper had a 2007 est...
), 10001 (New York City
New York City

The City of New York is the List of United States cities by population in the United States, while the New York metropolitan area ranks among the List of urban areas by population....
), 19103 (Philadelphia), 20008 (Washington, D.C.
Washington, D.C.

Washington, D.C. , formally the District of Columbia and commonly referred to as Washington, the District, or simply D.C., is the Capital of the United States, founded on July 16, 1790....
), 30303 (Atlanta
Atlanta, Georgia

Atlanta is the Capital and most populous city in Georgia , as well as the 33rd largest city in the United States of America with a population of 519,145....
) and 33130 (Miami
Miami, Florida

Miami is a global city in southeastern Florida, in the United States. Miami is the county seat of Miami-Dade County, Florida, the most populous county in Florida....
) (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.. For example, 40202 is in Louisville
Louisville, Kentucky

Louisville is Kentucky's largest city and county seat of Jefferson County, Kentucky. The city's estimated population as of 2006 is listed as 557,789, with a population of 1,233,733 in the Louisville-Jefferson County, KY-IN Metropolitan Statistical Area....
, 50309 in Des Moines, Iowa
Des Moines, Iowa

Des Moines , is the Capital and the most populous city in the United States U.S. state of Iowa. It is also the county seat of Polk County, Iowa....
, 60601 in Chicago
Chicago

Chicago is the largest city in the U.S. state of Illinois and the Midwestern United States, as well as the List of United States cities by population city in the United States with more than 2.8 million residents....
, 77063 in Houston, 80202 in Denver
Denver, Colorado

Denver is the Capital and the Colorado municipalities of the state of Colorado, in the United States. Denver is a consolidated city-county located in the South Platte River on the High Plains just east of the Front Range of the Rocky Mountains....
, 94111 in San Francisco
San Francisco, California

The City and County of San Francisco is the fourth most populous city in California and the List of United States cities by population in the United States, with a 2007 estimated population of 799,183....
, 98101 in Seattle
Seattle, Washington

Seattle is the most populous city in the US state of Washington and the Northwestern United States. The encompassing Seattle metropolitan area is the 15th largest in the United States, and the largest in the Pacific Northwest....
, and 99950 in Ketchikan, Alaska
Ketchikan, Alaska

Ketchikan is a city in Ketchikan Gateway Borough, Alaska, Alaska, United States, and the southeasternmost sizable city in that state. With an estimated population of 7,368 in 2007, it is the fifth most populous city in the state....
 (the highest ZIP code).

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 (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 (WA), Army Post Office Pacific (AP), Fleet Post Office Pacific (AP)


The next two digits represent the sectional center facility (e.g. 432xx = Columbus OH), and the fourth and fifth digits represents the area of the city (if in a metropolitan area), or a village/town (outside metro areas): 43209 (4=Ohio,32=Columbus,09=Bexley). When a sectional center facility's area crosses state lines, that facility is assigned separate three-digit prefixes for the states that it serves; thus, it is possible to identify the state associated with any ZIP Code just by looking at the first three digits.

Despite the geographic derivation of most ZIP codes, the codes themselves do not represent geographic regions; they generally correspond to address groups or delivery routes. Consequently, 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) Similarly, in areas without regular postal routes (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, U.S. government agencies in and around the capital are assigned ZIP codes starting with 20200 to 20599, which are Washington, D.C.
Washington, D.C.

Washington, D.C. , formally the District of Columbia and commonly referred to as Washington, the District, or simply D.C., is the Capital of the United States, founded on July 16, 1790....
, ZIP codes, even if they are not located in Washington itself. While the White House
White House

The White House is the official residence and principal workplace of the President of the United States. Located at 1600 Pennsylvania Avenue in Washington, D.C., it was built between 1792 and 1800 of white-painted Aquia sandstone in the late Georgian architecture and has been the executive residence of every U.S....
 itself is located in ZIP code 20006, it has the ZIP code 20500. The Nuclear Regulatory Commission
Nuclear Regulatory Commission

Nuclear Regulatory Commission is a United States government agency that was established by the Energy Reorganization Act of 1974 in 1974, and was first opened January 19, 1975....
 is located in Rockville, Maryland
Rockville, Maryland

Rockville is the county seat of Montgomery County, Maryland, United States. According to the 2007 census update, the city had a total population of 58,706, making it the third largest city in Maryland....
, at ZIP code 20852, but has been assigned by the Postal Service the address "Washington, DC 20555". The United States Patent and Trademark Office
United States Patent and Trademark Office

The United States Patent and Trademark Office is an agency in the United States Department of Commerce that issues patents to inventors and businesses for their inventions, and trademark registration for product and intellectual property identification....
 used to be located in Crystal City, Virginia
Crystal City, Virginia

Crystal City is an urban neighborhood in the southeastern corner of Arlington County, Virginia. Just south of downtown Washington, D.C., Crystal City is centered along a stretch of Jefferson Davis Highway , just south of The Pentagon, just east of Pentagon City, Virginia, and within walking distance to the west of Ronald Reagan Washington Nat...
 at ZIP Code 22202 but was assigned by the Postal Service the address "Washington, DC 20231"; however, since its move to Alexandria, Virginia
Alexandria, Virginia

Alexandria is an independent city in the Commonwealth of Virginia. As of the United States Census 2000, the city had a total population of 128,283....
, it uses the ZIP + 4 code 22313-1450.

Similarly, the ZIP code for the Metropolitan Washington Airports Authority
Metropolitan Washington Airports Authority

Metropolitan Washington Airports Authority is an independent airport authority, created by the United States Congress to oversee management, operations, and capital development of Washington, D.C.'s two major airports: Ronald Reagan Washington National Airport and Washington Dulles International Airport....
, a federally-chartered independent authority, is 20001-6000, even though the physical address of the Authority's office, "1 Aviation Circle", is in Arlington, Virginia
Arlington County, Virginia

Arlington County is an urban area county of about 206,800 residents in the Commonwealth of Virginia. It is located directly across the Potomac River to the west of Washington, D.C....
.

Rarely, 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. Generally, the locality is so isolated that it is most conveniently served from a sectional center in another state. Examples:
  • Fishers Island
    Fishers Island

    Fishers Island is a small island, approximately 9 miles long and 1 mile wide, in Suffolk County, New York in the U.S. state of New York. Fishers Island is a part of the Town of Southold, New York....
    , New York, bears the ZIP code 06390 and is served from Connecticut — all other New York ZIP codes (excepting those at Holtsville for the IRS
    Internal Revenue Service

    The Internal Revenue Service is the Federal government of the United States agency that collects taxes and enforces the tax law. It is an agency within the U.S....
    ) begin with "1".
  • Some Texas ZIP codes are served from New Mexico (most notably some El Paso
    El Paso, Texas

    El Paso is a city in and the county seat of El Paso County, Texas, Texas, United States, and part of the . According to the United States Census Bureau 2006 population estimates, the city had a population of 606,913....
     ZIP codes) and thus bear codes beginning with "885" (contiguous numerically with 870-884 NM) rather than "799".
  • Returned government parcels from the District of Columbia 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 anthrax scare
    2001 anthrax attacks

    The 2001 anthrax attacks in the United States, also known as Amerithrax from its Federal Bureau of Investigation case name, occurred over the course of several weeks beginning on September 18, 2001....
    ).
  • Some Arkansas roads north of Bull Shoals Lake
    Bull Shoals Lake

    Bull Shoals Lake is a man-made lake in the Ozark Mountains of northern Arkansas and southern Missouri. It has hundreds of miles of lake arms and coves perfect for boating, water sports, swimming, and fishing....
     can best be accessed by the Protem, Missouri
    Protem, Missouri

    Protem is an unincorporated area in southeastern Taney County, Missouri, Missouri, United States, about ten miles north of the Arkansas state line....
    , delivery unit (ZIP Code 65733).
  • Fort Campbell (ZIP Code 42223), primarily in Kentucky, also has some roads in Tennessee.


ZIP codes only loosely tied to cities
A ZIP code's address and the "city" name written on the same line do not necessarily mean that that address is within that city. The Postal Service designates a single "default" place name for each ZIP code. This may be an actual incorporated town or city, a subentity of a town or city or an unincorporated census-designated place. Additional place names, also of any of these types, 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.

Default 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 only "acceptable" and not the "default" place name. Many databases automatically assign the "default" place name for a ZIP code, without regard to any "acceptable" place names. For example, Centennial, Colorado
Centennial, Colorado

The City of Centennial is a Colorado municipalities#Home_Rule_City located in Arapahoe County, Colorado, Colorado, United States. The city was estimated to have a total population of 98,243 in 2005....
, is divided among seven ZIP codes assigned to "Aurora
Aurora, Colorado

Aurora is a Colorado municipalities#Home Rule Municipality that is the Colorado municipalities in the Colorado and the list of United States cities by population in the United States....
", "Englewood
Englewood, Colorado

The City of Englewood is a Colorado municipalities#Home_Rule_Municipality located in Arapahoe County, Colorado, Colorado, United States. As of 2005, the city is estimated to have a total population of 32,350....
" or "Littleton
Littleton, Colorado

Littleton is a Colorado municipalities#Home_Rule_Municipality in Arapahoe County, Colorado, Douglas County, Colorado, and Jefferson County, Colorado counties in the U.S....
" as its "default" place names. Thus, from the perspective of the U.S. Postal Service, the city of Centennial and its 100,000 residents do not exist - they are 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 often 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 "default" name can be used, even when many addresses in the ZIP code are in another city. For example, approximately 85% of the area served by the ZIP code 85254, to which the place name "Scottsdale, Arizona
Scottsdale, Arizona

Scottsdale is a city in the eastern part of Maricopa County, Arizona, United States, adjacent to Phoenix, Arizona. As of 2007 the population of the city was 240,410....
," is assigned, is actually inside the city limits of neighboring Phoenix
Phoenix, Arizona

Phoenix is the capital and largest city in the U.S. state of Arizona, as well as the fifth most populous city in the United States. Phoenix is home to 1,552,259 residents, and is the anchor of the Phoenix Metropolitan Area with 4,179,427 residents....
. This is because the post office that serves this area is in Scottsdale. This has led some residents of the ZIP code to believe that they live in Scottsdale when they actually live in Phoenix. A Scottsdale website listing the positive and negative aspects of the city mentioned the 85254 ZIP code as a positive aspect because "Scottsdale" is being used for businesses located outside the Scottsdale city limits.

The result of this is that sometimes people must use the name of a different city than their own. An example is Missouri City, Texas, which is in both Harris and Fort Bend counties and is a suburb of Houston. The portion which is within Harris county is within the ZIP code 77071, which must use the city "Houston" instead of Missouri City. A tiny portion of the city of Houston is in Fort Bend county in the ZIP code 77489, and residents there must use the city "Missouri City" for their address even though they are within the city limits of Houston. A former mayor and a city council member in Houston lived in Fort Bend county and were accused of not living in Houston since they had an address of Missouri City.

This phenomenon is repeated across the country. The previously mentioned Englewood 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 metropolitan area
Denver-Aurora Metropolitan Area

The Denver-Aurora Metropolitan Statistical Area is a United States Census Bureau defined United States metropolitan area in the Colorado that includes the Denver, Colorado and nine suburban counties....
, and ZIP codes in this area were assigned "Englewood" as their "default" place name. An employment center as large as downtown Denver has grown in this area, and its office parks are the headquarters for many internationally recognized corporations. Even though they are actually located in other cities, they indicate "Englewood" as their location, as this is the "default" postal place name. As a result, there are really two "Englewoods" — the actual city, small and with a largely 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 that they live or work in "Englewood" and identify closely with it may rarely enter the actual city of that name. 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.

"Acceptable place names" also come into play in areas of the country where many citizens identify more strongly with a particular urban center than the municipality they actually live in. For example, Allegheny County, Pennsylvania
Allegheny County, Pennsylvania

Allegheny County is a county in the southwestern part of the U.S. state of Pennsylvania. As of the United States Census 2000, the population was 1,281,666....
, has 130 distinct municipalities, but many of the county's residents, and even some residents of adjacent counties, commonly use "Pittsburgh, PA" as their postal address. The same thing applies in many cities that have more than one ZIP code, like Evansville, Indiana, or Jacksonville, Florida.

Finally, many ZIP codes are for villages, census-designated place
Census-designated place

A census-designated place is a type of Place identified by the United States Census Bureau for statistical purposes. CDPs are delineated for each decennial census as the statistical counterparts of incorporated places such as city, towns and villages....
s, portions of cities, or other entities that are not municipalities. For example, ZIP code 03750 is for Etna, New Hampshire
Etna, New Hampshire

Etna, originally named "Mill Village," is a small village within the town of Hanover, New Hampshire, in the United States. It is located in southwestern Grafton County, New Hampshire, approximately east of Hanover's downtown and south of the village of Hanover Center, on Mink Brook....
, but Etna is not a city or town; it is actually a village district
Village (United States)

In the United States, a village is a term, sometimes informal, for a type of administrative division at the local government in the United States level....
 in the town of Hanover
Hanover, New Hampshire

Hanover is a town along the Connecticut River in Grafton County, New Hampshire, New Hampshire, United States. The population was 10,850 at the 2000 census....
, which itself is assigned the ZIP code 03755. Another example is ZIP code 08043, which corresponds to the census-designated place of Kirkwood, NJ, but actually serves the entirety of Voorhees Township, NJ. This is also the case in LaGrange, New York
LaGrange, New York

LaGrange is a town in Dutchess County, New York, New York, United States. The population was 14,928 at the 2000 census. The town was named after the ancestral estate of the Marquis de Lafayette....
, a portion of which is served by the 12603 ZIP code based in the neighboring town of Poughkeepsie
Poughkeepsie (town), New York

Poughkeepsie is a town in Dutchess County, New York, New York, United States. The population was 42,777 at the 2000 census. The name is derived from the native term, "Uppu-qui-ipis-in," which means "reed-covered hut by the water."...
. 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
Willow Grove, Pennsylvania

Willow Grove is a census-designated place in Montgomery County, Pennsylvania, Pennsylvania, about 10 miles north of Philadelphia. The population was 16,234 at the 2000 census....
, served by the 19090 ZIP code, is a village that straddles the border of Upper Moreland Twp.
Upper Moreland Township, Pennsylvania

Upper Moreland Township is a township in Montgomery County, Pennsylvania, Pennsylvania, United States. The population was 24,993 at the 2000 census....
 and Abington Twp., and that post office also serves a small portion of Horsham Twp.
Horsham Township, Pennsylvania

Horsham Township is a township in Montgomery County, Pennsylvania, Pennsylvania, United States. The population was 24,232 at the 2000 census, and was chosen as the 15th best place to live in the United States by Money Magazine in their 2007 Top 100 Best Places to Live....
. Another example is Armstrong Township of Vanderburgh County, Indiana
Vanderburgh County, Indiana

Vanderburgh County is a county located in the U.S. state of Indiana. As of 2000, the population was 171,922. The county seat is in Evansville, Indiana....
. While the rest of the county uses the 477 prefix, Armstrong Township, despite having no incorporated town, uses the ZIP code 47617 and addresses itself "Armstrong, Indiana". Furthermore, non-municipal place names may also share ZIP codes with municipal place names. For example, West Windsor Township, New Jersey
West Windsor Township, New Jersey

West Windsor Township is a Township in Mercer County, New Jersey, New Jersey, in the United States. As of the United States Census, 2000, the township population was 21,907....
, is commonly referred to as Princeton Junction
Princeton Junction

Princeton Junction could refer to:*Princeton Junction, New Jersey, a census-designated place located in West Windsor, New Jersey in Mercer County, New Jersey....
 in most mailing databases, despite the fact that Princeton Junction is not a city at all. Instead, it refers to a census-designated area within West Windsor.

The 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 "default" place name associated with their ZIP codes. Because of the confusion and lack of identity generated by this situation, some cities, such as Signal Hill, California
Signal Hill, California

Signal Hill is a small city in Los Angeles County, California, California that is an enclave . As of 2005, the city population was 10,951. The city was Municipal corporation on April 22, 1924, roughly three years after oil was discovered on Signal Hill....
, have successfully petitioned the Postal Service to change ZIP-code boundaries or create new ZIP codes so that their cities can be the "default" place name for addresses within the ZIP code.

This confusion also can have financial implications for local governments, because mail volume is among the factors used by the U.S. Census Bureau to estimate population changes between decennial census enumerations. Sometimes local officials in a community that is not the "default" 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 will get fewer State and Federal funds that are computed based on population.

Division and reallocation of ZIP codes
Like area codes, ZIP codes are sometimes divided and changed, especially when a rural
Rural

Rural areas are large and isolated areas of a country, often with low populations. Today, 75 percent of the United States' inhabitants live in suburban and urban areas, but cities occupy only 2 percent of the country....
 area becomes suburb
Suburb

Suburbs are commonly defined as the residential areas which surround the central area of the urban area of a town or city. In the United States, suburbs have a prevalence of usually detached single-family homes.....
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.

Most significantly, 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 Dulles Airport
Washington Dulles International Airport

Washington Dulles International Airport is a public airport located 25 miles west of the central business district of Washington, D.C., in Dulles, Virginia ....
 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
Montgomery County, Maryland

Montgomery County of the U.S. state of Maryland is situated just north of Washington, D.C. and southwest of Baltimore. It is one of the most affluent counties in the nation, and has the highest percentage of residents over 25 years old who hold a post-graduate degree....
, 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
Silver Spring, Maryland

Silver Spring is an urbanized, unincorporated area in Montgomery County, Maryland, United States. After Baltimore, Maryland and Columbia, Maryland, the Silver Spring Census-designated place is the third most populous place in Maryland....
 (whose postal area includes Wheaton
Wheaton, Maryland

Wheaton is an unincorporated, urbanized area in Montgomery County, Maryland, United States, north of Washington, D.C., northwest of Silver Spring, Maryland....
) 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.

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
Marion Barry

Marion Shepilov Barry, Jr. , is an American politician who served as the second elected List of mayors of Washington, D.C. of Washington, D.C. from 1979 to 1991, and again as the fourth mayor from 1995 to 1999....
, the USPS realigned the postal boundaries between the District of Columbia and Maryland to match the actual boundary. Previously, many inner suburbs, such as Bethesda
Bethesda, Maryland

Bethesda is a census designated place in southern Montgomery County, Maryland, United States, just northwest of Washington, D.C. It takes its name from a local church, the Bethesda Presbyterian Church, built in 1820 and rebuilt in 1850, which in turn took its name from Jerusalem's Pool of Bethesda....
 and Takoma Park
Takoma Park, Maryland

Takoma Park is a city in Montgomery County, Maryland, Maryland. The population was 17,299 at the 2000 census....
, 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.

By type/use

There are four types of ZIP codes: Unique (assigned to a single high-volume address), P.O.-box-only (used only for P.O. 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
Mail

Mail, or post, is a method for transmitting information and tangible objects, wherein written documents, typically enclosed in envelopes, and also small packages, are delivered to destinations around the world....
 have their own ZIP codes, such as 81009 for the Federal Citizen Information Center
Federal Citizen Information Center

The Federal Citizen Information Center , originally the Federal Consumer Information Center, is a department in the United States government's General Services Administration....
 of the U.S. General Services Administration (GSA) in Pueblo, Colorado
Pueblo, Colorado

Pueblo is a Colorado municipalities#Home Rule Municipality that is the county seat and the most populous city of Pueblo County, Colorado, Colorado, United States....
; 30385 for BellSouth
BellSouth

BellSouth Corporation is an United States telecommunications holding company based in Atlanta, Georgia. BellSouth was one of the seven original Regional Bell operating company after the United States Department of Justice forced the American Telephone & Telegraph Company to divest itself of its regional telephone companies on January 1, 1984....
 in Atlanta; 21412 for Bancroft Hall
Bancroft Hall

Bancroft Hall at the United States Naval Academy in Annapolis, Maryland, Maryland, is the largest single dormitory in the world. Bancroft Hall, named after former United States Secretary of the Navy George Bancroft, is home for the entire brigade of 4,000 midshipmen, and contains some 1,700 rooms, of corridors, and of floor space....
, the midshipman dormitory at the United States Naval Academy
United States Naval Academy

The United States Naval Academy is an undergraduate college in Annapolis, Maryland, United States, that educates and commissions officers of the United States Navy and United States Marine Corps....
; and 12345 for General Electric
General Electric

The General Electric Company, or GE is a multinational corporation United States technology and Service s conglomerate incorporated in the State of New York....
 in Schenectady, New York
Schenectady, New York

Schenectady is a city in Schenectady County, New York, New York, United States, of which it is the county seat. As of the United States Census 2000, the city had a population of 61,821, making it the ninth-largest city in New York....
. An example of a P.O.-box-only ZIP code is 22313, which is used for P.O. boxes at the main post office in Alexandria, Virginia
Alexandria, Virginia

Alexandria is an independent city in the Commonwealth of Virginia. As of the United States Census 2000, the city had a total population of 128,283....
, as well as for the United States Patent and Trademark Office
United States Patent and Trademark Office

The United States Patent and Trademark Office is an agency in the United States Department of Commerce that issues patents to inventors and businesses for their inventions, and trademark registration for product and intellectual property identification....
. In the area surrounding that post office, home and business mail delivery addresses use ZIP code 22314, which is thus a Standard ZIP code.

The above will be made clearer by examining the allocation of ZIP codes in Princeton, New Jersey
Princeton, New Jersey

Princeton, New Jersey is located in Mercer County, New Jersey, New Jersey, United States. Princeton University has been sited in the town since 1756....
:
  • 08540 - standard (deliveries in most of the Princeton postal area)
  • 08541 - unique (Educational Testing Service
    Educational Testing Service

    Educational Testing Service is the world's largest private educational testing and measurement organization, operating on an annual budget of approximately $1.1 billion on a proforma basis in 2007....
    )
  • 08542 - standard (deliveries in the central area of the borough of Princeton, and also some PO boxes)
  • 08543 - PO box only (PO boxes at the main post office)
  • 08544 - unique (Princeton University
    Princeton University

    Princeton University is a private university university located in Princeton, New Jersey, New Jersey, United States. The school is one of the eight universities of the Ivy League and has the largest per-student Financial endowment in the world....
    )


Non-standard examples


  1. While ZIP codes classified as Unique by the USPS always serve a single address, it should not be assumed that a ZIP code is Unique simply because it serves a single building, complex, or address. Large facilities are often given P.O.-box-only or Standard ZIP codes rather than Unique ZIP codes, because USPS carriers must distribute the mail to multiple boxes, offices, or buildings within the facility. In a Unique ZIP code, mail distribution within the single address is handled internally, rather than by USPS employees.
  2. A few ZIP codes fall outside the three types. APO
    Military mail

    Military mail is a special military mail, used to integrate the civil postal system in a given country with that country's military posted overseas....
     and FPO
    Military mail

    Military mail is a special military mail, used to integrate the civil postal system in a given country with that country's military posted overseas....
     ZIP codes are codes in use for U.S Armed Forces members and their dependents overseas. The state postal abbreviations AP (Armed Forces Pacific), AA (Armed Forces Americas) and AE (Armed Forces Europe) were created in 1991 to serve these communities; previously, APO and FPO mail was addressed to APO San Francisco, APO Miami and APO New York
    New York City

    The City of New York is the List of United States cities by population in the United States, while the New York metropolitan area ranks among the List of urban areas by population....
     respectively, and APO/FPO ZIP codes were numerically close to the allocations for those cities. The creation of these new state codes necessitated the rewrite of thousands of pieces of postal software and still occasionally causes confusion, as the actual numeric ZIP codes used by the APO/FPO system did not change and are still in use.
  3. New York City, NY is an extreme example. It is composed of five counties that are also boroughs within the city. They each have one or more SCF Codes.
  • Brooklyn: 112
  • Bronx: 104
  • New York, NY (Manhattan):


100 (Standard); 101 (P.O. Boxes and Unique); 102 (P.O. Boxes and Unique).
  • Queens:


110 (Floral Park); 111 (Long Island City); 113 (Flushing); 114 (Jamaica); 116 (Far Rockaway)
  • Staten Island: 103


In the case of the four boroughs other than Queens, the official, “accepted” names are the same, while in the case of Queens the borough name is not accepted as an address; the SCF name is. In addition, the numerous “Accepted” names are official as well. In the case of
SCF 110 (Floral Park), it serves both eastern Jamaica, eastern Flushing, and northwestern Nassau
Nassau County, New York

Nassau County is a suburban Political subdivisions of New York State#County in the New York Metropolitan Area east of New York City in the U.S....
 as well.

Other uses


Delivery services

Delivery services other than the USPS, such as FedEx
FedEx

FedEx Corporation , originally known as FDX Corporation, is a logistics services company, based in the United States. The name "FedEx" is a syllabic abbreviation of the name of the company's original air division, Federal Express, which was used until 2000....
, United Parcel Service
United Parcel Service

United Parcel Service, Inc. , commonly referred to as UPS, is the world's largest package delivery company. UPS delivers more than 15 million packages a day to 6.1 million customers in more than 200 countries and territories around the world....
 and DHL
DHL

DHL Express , is a division of Deutsche Post World Net providing international express mail services....
 require a ZIP code for optimal internal routing of a package. This spares customers from being required to use some other routing designator, such as the IATA code
IATA airport code

An IATA airport code, also known an IATA location identifier, IATA station code or simply a location identifier, is a three-letter code designating many airports around the world, defined by the International Air Transport Association ....
 of the destination airport or railhead
Railhead

A railhead is a terminus of a Rail transport line that interfaces with another transport mode, such as shipping....
.

Statistics

ZIP codes are used not only for tracking of mail but in gathering geographical statistics in the United States. The U.S. Census Bureau
United States Census Bureau

The United States Census Bureau is the government agency that is responsible for the United States Census. It also gathers other national demographic and economic data....
 has data that include the latitude
Latitude

Latitude, usually denoted symbolically by the Greek letter phi gives the location of a place on Earth north or south of the equator. Lines of Latitude are the horizontal lines shown running east-to-west on maps ....
 and longitude
Longitude

Longitude , symbolized by the Greek character lambda , is the geographic coordinate most commonly used in cartography and global navigation for east-west measurement....
 of the center-point of some ZIP codes (called ZIP Code Tabulation Area
ZIP Code Tabulation Area

ZIP Code Tabulation Areas are a new statistical entity developed by the United States Census Bureau for tabulating summary statistics from United States 2000 Census....
s or ZCTAs). The Census Bureau does not keep up-to-date datasets of all ZIP codes. Complete datasets are commercially available.

Marketing

The data are often used in direct mail marketing campaigns in a process called ZIP-code marketing, developed by Martin Baier. Point-of-sale
Point of sale

Point of sale or point of service can mean a retailing, a checkout counter in a shop, or the location where a financial transaction occurs....
 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
Insurance

Insurance, in law and economics, is a form of risk management primarily used to Hedge against the risk of a contingent loss. Insurance is defined as the equitable transfer of the risk of a loss, from one entity to another, in exchange for a premium, and can be thought of as a guaranteed small loss to prevent a large, possibly devastating los...
-industry
Industry

An industry is the manufacturing of a Good or Service within a category. Although industry is a broad term for any kind of economic production, in economics and urban planning industry is a synonym for the secondary sector, which is a type of economic activity involved in the manufacturing of raw materials into goods and products....
 and banking practice pejorative
Pejorative

Words and phrases are pejorative if they imply disapproval or contempt. When used as an adjective, pejorative is synonymous with derogatory, derisive, dyslogistic, and contemptuous....
ly known as redlining
Redlining

Redlining is the practice of denying or increasing the cost of services such as banking, insurance, access to jobs, access to health care, or even supermarkets to residents in certain, often racially determined, areas....
. 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.

Internet

ZIP code data is an integral part of dealer/store locator software
Locator software

Locator software is an electronic commerce software module on a website that allows a visitor to find nearby stores and business locations. In its most common form, a visitor inputs a ZIP code and the locator returns all locations in a database within a specified radius....
 on many web sites, especially brick-and-click
Bricks and clicks

Bricks-and-clicks is a business model by which a company integrates On-line and off-line presences. It is also known as click-and-mortar or clicks-and-bricks, as well as bricks, clicks and flips, flips referring to catalogs....
 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.

Pop culture

  • In 1964, at the height of his popularity, Smokey Bear
    Smokey Bear

    Smokey Bear is a mascot of the United States Forest Service created to educate the public on the dangers of forest fires.Smokey Bear's message "Only You Can Prevent Forest Fires" was created in 1944 by the Ad Council....
    , mascot of the U.S. Forest Service, received so much fan mail that he was assigned his own ZIP code, 20252.
  • ZIP codes can take on a certain amount of cachet or become bywords: 90210, in Beverly Hills
    Beverly Hills, California

    Beverly Hills is a city in the western part of Los Angeles County, California, California, United States. Beverly Hills and the neighboring city of West Hollywood, California are together entirely surrounded by the city of Los Angeles, California....
    , California
    California

    California is a U.S. state on the West Coast of the United States of the United States, along the Pacific Ocean. It is bordered by Oregon to the north, Nevada to the east, Arizona to the southeast, and to the south the Mexico state of Baja California....
    , probably the most famous example, appears in the titles of three Beverly Hills–centered television shows: Beverly Hills 90210, Dr. 90210
    Dr. 90210

    Dr. 90210 is a reality television focusing on plastic surgery in the wealthy suburb of Beverly Hills, California in Los Angeles, California, California....
    , and 90210
    90210 (TV series)

    '90210' is a teen drama developed by Rob Thomas , Jeff Judah and Gabe Sachs. It is the fourth series in the Beverly Hills, 90210 franchise created by Darren Star....
    . Another example is the area around Harvard Square
    Harvard Square

    Harvard Square is a large triangular area in the center of Cambridge, Massachusetts, Massachusetts, at the intersection of Massachusetts Avenue , Brattle Street, and John F....
     in Cambridge
    Cambridge, Massachusetts

    Cambridge is a city in the Greater Boston area of Massachusetts, United States. It was named in honor of the University of Cambridge in England....
    , Massachusetts
    Massachusetts

    The Commonwealth of Massachusetts is a U.S. state located in the New England region of the Northeastern United States United States. It borders Rhode Island and Connecticut to the south, New York to the west, and Vermont and New Hampshire to the north....
    , whose ZIP code 02138 is now the title of a magazine
    02138

    02138 is an independent magazine featuring graduates of Harvard University. It is however not actually affiliated with the school. The title is a reference to the postal ZIP code of where Harvard University's main campus is located in Harvard Square, Cambridge, Massachusetts....
    , which was discontinued on October 24, 2008.
  • On the PBS children's series ZOOM
    ZOOM

    ZOOM was an United States educational television show, created almost entirely by children, which aired on PBS from January 1972 to March 1978....
     the young cast members would sing the address "ZOOM, that's Z double-oh M/Box Three Five Oh/Boston Mass Oh Two One Three Four." 02134 was the ZIP code of WGBH, the show's originating station in Boston
    Boston, Massachusetts

    Boston is the State capital and largest city of the Commonwealth of Massachusetts, and is one of the oldest cities in the United States. The largest city in New England, Boston is considered the economic and cultural center of the region, and is sometimes regarded as the unofficial "Capital of New England." Boston city proper had a 2007 est...
    , Massachusetts
    Massachusetts

    The Commonwealth of Massachusetts is a U.S. state located in the New England region of the Northeastern United States United States. It borders Rhode Island and Connecticut to the south, New York to the west, and Vermont and New Hampshire to the north....
    . When the show was reincarnated in 1999, the address would still be sung, along with the addition of the show's internet address.


See also

  • Postal code
    Postal code

    A postal code is a series of letters and/or numerical digits appended to a address for the purpose of sorting mail.Germany was the first country to introduce a postal code system, in 1941....
  • OneCode
  • ZIP Code Tabulation Area
    ZIP Code Tabulation Area

    ZIP Code Tabulation Areas are a new statistical entity developed by the United States Census Bureau for tabulating summary statistics from United States 2000 Census....
  • Intelligent Mail Barcode
    Intelligent Mail Barcode

    The Intelligent Mail barcode is a 65-bar code planned for use on mail in the United States. The hope is that it may provide information and benefits to both mailers and postal officials....


External links

  • webpage from the United States Postal Service
    United States Postal Service

    The United States Postal Service is an Independent agencies of the United States government responsible for providing postal service in the United States....
    .