Several sets of codes and abbreviations are used to represent the political divisions of the United States for postal addresses, data processing, general abbreviations, and other purposes.
This table includes abbreviations for three independent nations related to the United States through Compacts of Free Association, and other comparable postal abbreviations, including those now obsolete.
|Name and status of region||ISO||ANSI||USPS||USCG||GPO||AP||Other|
|Federal district||US-DC||DC||11||DC||DC||D.C.||D.C.||Wash. D.C.|
|State||US-IL||IL||17||IL||IL||Ill.||Ill.||Il., Ills., Ill's|
|State ("Commonwealth")||US-KY||KY||21||KY||KY||Ky.||Ky.||Ken., Kent.|
|State||US-NM||NM||35||NM||NM||N. Mex.||N.M.||New M.|
|State ("Commonwealth")||US-PA||PA||42||PA||PA||Pa.||Pa.||Penn., Penna.|
|State||US-RI||RI||44||RI||RI||R.I.||R.I.||R.I. & P.P., R. Isl.|
|State||US-WV||WV||54||WV||WV||W. Va.||W.Va.||W.V., W. Virg.|
|Insular area (Territory)||AS|
|Insular area (Territory)||GU|
|Insular area (Commonwealth)||MP|
|Insular area (Commonwealth)||PR|
|Insular area (Territory)||VI|
|U.S. Minor Outlying Islands||Insular areas||UM|
|Freely associated state||FM|
|Freely associated state||MH|
|Freely associated state||PW|
|U.S. Armed Forces – Americas||US military mail code||AA|
|U.S. Armed Forces – Europe||US military mail code||AE|
|U.S. Armed Forces – Pacific||US military mail code||AP|
|Obsolete postal code||CM|
|Obsolete postal code||PZ|
|Obsolete postal code||NB|
|Obsolete postal code||PH|
|Obsolete postal code||PC|
As early as October 1831, the United States Post Office recognized common abbreviations for states and territories. However, they only accepted these abbreviations because of their popularity, preferring that patrons spell names out in full to avoid confusion.
The traditional abbreviations for U.S. states and territories, widely used in mailing addresses prior to the introduction of two-letter U.S. postal abbreviations, are still commonly used for other purposes (such as legal citation), and are still recognized (though discouraged) by the Postal Service.
Modern two-letter abbreviated codes for the states and territories originated in October 1963, with the issuance of Publication 59: Abbreviations for Use with ZIP Code, three months after the Post Office introduced ZIP codes in July 1963. The purpose, rather than to standardize state abbreviations per se, was to make room in a line of no more than 23 characters for the city, the state, and the ZIP code.
Since 1963, only one state abbreviation has changed. Originally Nebraska was "NB"; but, in November 1969, the Post Office changed it to "NE" to avoid confusion with New Brunswick in Canada.
The two-letter postal abbreviation system is complicated by the fact that several state names begin with the same letter (e.g., eight state names begin with M and eight begin with N, four "New" and two "North"). To avoid duplications, some abbreviations are not intuitive.
Prior to 1987, when the U.S. Secretary of Commerce approved the two-letter codes for use in government documents,the United States Government Printing Office (GPO) suggested its own set of abbreviations, with some states left unabbreviated. Today, the GPO supports United States Postal Service standard.
The Associated Press Stylebook, the usage guide for most United States newspapers, counsels the use of abbreviations for most state names, when appended to a city name (for example, "Santa Ana, Calif."). AP suggests spelling out the names of Alaska, Hawaii, and all states with five or fewer letters; and, unlike the old GPO recommendations, AP suggests spelling out the names of all non-state territories, with the exception of the District of Columbia (D.C.). Legal citation manuals, such as The Bluebook and The ALWD Citation Manual , typically use these "traditional abbreviations" or variants thereof.
The American National Standards Institute (ANSI) established alphabetic and numeric codes for each state and outlying areas in ANSI standard INCITS 38:2009. ANSI standard INCITS 38:2009 replaced the Federal Information Processing Standard (FIPS) standards FIPS 5-2, FIPS 6-4, and FIPS 10-4. The ANSI alphabetic state code is the same as the USPS state code except for U.S. Minor Outlying Islands, which have an ANSI code "UM" but no USPS code—and U.S. Military Mail locations, which have USPS codes ("AA", "AE", "AP") but no ANSI code.
The United States Postal Service (USPS) has established a set of uppercase abbreviations to help process mail with optical character recognition and other automated equipment.There are also official USPS abbreviations for other parts of the address, such as street designators (street, avenue, road, etc.).
These postal abbreviations are distinguished from traditional abbreviations such as Calif., Fla., or Tex. The Associated Press Stylebook states that in contexts other than mailing addresses, the traditional state abbreviations should be used.However, the Chicago Manual of Style now recommends use of the uppercase two-letter abbreviations, with the traditional forms as an option.
The postal abbreviation is the same as the ISO 3166-2 subdivision code for each of the fifty states.
These codes do not overlap with the 13 Canadian subnational postal abbreviations. The code for Nebraska changed from NB to NE in November 1969 to avoid a conflict with New Brunswick.Canada likewise chose MB for Manitoba to prevent conflict with either Massachusetts (MA), Michigan (MI), Minnesota (MN), Missouri (MO), or Montana (MT).
The U.S. Coast Guard (USCG) uses a set of two-letter prefixes for vessel numbers; red in the table above.39 states and the District of Columbia have the same USPS and USCG abbreviations. USCG prefixes have also been established for five outlying territories; all are the same as the USPS abbreviations except the Mariana Islands. The twelve cases where USPS and USCG abbreviations differ are listed below and marked in
Country codes are short alphabetic or numeric geographical codes (geocodes) developed to represent countries and dependent areas, for use in data processing and communications. Several different systems have been developed to do this. The term country code frequently refers to ISO 3166-1 alpha-2 or international dialing codes, the E.164 country calling codes.
Federal Information Processing Standards (FIPS) are publicly announced standards developed by the National Institute of Standards and Technology for use in computer systems by non-military American government agencies and government contractors.
ISO 3166 is a standard published by the International Organization for Standardization (ISO) that defines codes for the names of countries, dependent territories, special areas of geographical interest, and their principal subdivisions. The official name of the standard is Codes for the representation of names of countries and their subdivisions.
A postal code is a series of letters or digits or both, sometimes including spaces or punctuation, included in a postal address for the purpose of sorting mail.
A ZIP Code is a postal code used by the United States Postal Service (USPS). Introduced in 1963, the basic format consists of five digits. In 1983, an extended ZIP+4 code was introduced; it includes the five digits of the ZIP Code, followed by a hyphen and four digits that designate a more specific location.
FIPS state codes were numeric and two-letter alphabetic codes defined in U.S. Federal Information Processing Standard Publication 5-2 to identify U.S. states and certain other associated areas. The standard superseded FIPS PUB 5-1 on May 28, 1987, and was superseded on September 2, 2008, by ANSI standard INCITS 38:2009.
ISO 3166-2:CA is the entry for Canada in ISO 3166-2, part of the ISO 3166 standard published by the International Organization for Standardization (ISO), which defines codes for the names of the principal subdivisions of all countries coded in ISO 3166-1.
ISO 3166-2:US is the entry for the United States in ISO 3166-2, part of the ISO 3166 standard published by the International Organization for Standardization (ISO), which defines codes for the names of the principal subdivisions of all countries coded in I 3166-1.
ISO 3166-1 is part of the ISO 3166 standard published by the International Organization for Standardization (ISO), and defines codes for the names of countries, dependent territories, and special areas of geographical interest. The official name of the standard is Codes for the representation of names of countries and their subdivisions – Part 1: Country codes. It defines three sets of country codes:
ISO 3166-1 alpha-2 codes are two-letter country codes defined in ISO 3166-1, part of the ISO 3166 standard published by the International Organization for Standardization (ISO), to represent countries, dependent territories, and special areas of geographical interest. They are the most widely used of the country codes published by ISO, and are used most prominently for the Internet's country code top-level domains. They are also used as country identifiers extending the postal code when appropriate within the international postal system for paper mail, and has replaced the previous one consisting one-letter codes. They were first included as part of the ISO 3166 standard in its first edition in 1974.
These are data codes for Switzerland.
The Geographic Names Information System (GNIS) is a database that contains name and locative information about more than two million physical and cultural features located throughout the United States of America and its territories. It is a type of gazetteer. GNIS was developed by the United States Geological Survey in cooperation with the United States Board on Geographic Names (BGN) to promote the standardization of feature names.
An address is a collection of information, presented in a mostly fixed format, used to give the location of a building, apartment, or other structure or a plot of land, generally using political boundaries and street names as references, along with other identifiers such as house or apartment numbers and organization name. Some addresses also contain special codes, such as a postal code, to make identification easier and aid in the routing of mail.
Canadian provincial and territorial postal abbreviations are used by Canada Post in a code system consisting of two capital letters, to represent the 13 provinces and territories on addressed mail. These abbreviations allow automated sorting.
Geolocation is the identification or estimation of the real-world geographic location of an object, such as a radar source, mobile phone, or Internet-connected computer terminal. In its simplest form, geolocation involves the generation of a set of geographic coordinates and is closely related to the use of positioning systems, but its usefulness is enhanced by the use of these coordinates to determine a meaningful location, such as a street address.
ISO 3166-2:UM is the entry for the United States Minor Outlying Islands in ISO 3166-2, part of the ISO 3166 standard published by the International Organization for Standardization (ISO), which defines codes for the names of the principal subdivisions of all countries coded in ISO 3166-1.