A postal code (known in various countries as a post code, postcode, or ZIP code) is a series of letters and/or digits appended to a postal address for the purpose of sorting mail. Once postal codes were introduced, other applications became possible.
In February 2005, 117 of the 190 member countries of the Universal Postal Union had postal code systems. Countries that do not have national systems include Ireland and Panama. Although Hong Kong and Macau are now Special Administrative Regions of China, each maintains its own long-established postal system, which does not utilize postal codes for domestic mail, and no postal codes are assigned to Hong Kong and Macau. Mail between Hong Kong, Macau and mainland China is treated as international.
Although postal codes are usually assigned to geographical areas, special codes are sometimes assigned to individual addresses or to institutions that receive large volumes of mail, such as government agencies and large commercial companies. One example is the French CEDEX system.
There are a number of colloquial terms for postal code.
Postal codes were first introduced in the Union of Soviet Socialist Republics in December 1932,[1] but the system was abandoned in 1939. The next country to introduce postal codes was Germany in 1941,[2] followed by Argentina in 1958, the United Kingdom in 1959,[3] the United States in 1963[4] and Switzerland in 1964.[5]
The characters used in postal codes are
Postal codes in the Netherlands originally did not use the letters 'F', 'I', 'O', 'Q', 'U' and 'Y' for technical reasons. But as almost all existing combinations are now used, these letters were allowed for new locations starting 2005. The letter combinations SS, SD and SA are not used for historical reasons.
Postal codes in Canada do not include the letters D, F, I, O, Q, or U, as the OCR equipment used in automated sorting could easily confuse them with other letters and digits. The letters W and Z are used, but are not currently used as the first letter.
Most of the postal code systems are numeric, only a few are alphanumeric (i.e. use both letters and digits). Alphanumeric systems can, given the same number of digits, encode many more locations. They are often more precise, as is the case in the United Kingdom or in the Netherlands, where a postal code corresponds to a street or even a building, meaning the post code and the number of the home/business is all that is needed for accurate delivery. However, there is no a priori reason why numeric postal codes cannot be equally precise, as illustrated by 9- and 11-digit codes in the United States. The independent nations using alphanumeric postal code systems are:
Usage of ISO 3166-1 alpha-2 codes was recommended to be used starting in 1994,[7] but they have not become widely used. The European Committee for Standardization recommends use of ISO Alpha-2 codes for international postcodes[7] and a UPU guide on international addressing states that "administrations may recommend" the use of ISO Alpha-2 codes.[8]
Andorra, Ecuador, Latvia, Moldova, Slovenia use the ISO 3166-1 alpha-2 as prefix in their postal codes.
In some countries (such as those of continental Europe, where a postcode format of four or five numeric digits is commonly used) the numeric postal code is sometimes prefixed with a country code to avoid confusion when sending international mail to or from that country. Recommendations by official bodies responsible for postal communications are confusing regarding this practice.[7] For many years, licence plate codes — for instance "D-" for Germany or "F-" for France — were used, although this was not accepted by the Universal Postal Union (UPU).[7]
Postal services have their own formats and placement rules for postal codes. In most English-speaking countries, the postal code forms the last item of the address, following the city or town name, whereas in most continental European countries it precedes the name of the city or town.
When it follows the city it may be on the same line or on a new line.
In Japan, China, Korea and the Russian Federation, it is written more to the beginning of an address.
Postal codes are usually assigned to geographical areas. Sometimes codes are assigned to individual addresses or to institutions that receive large volumes of mail, e.g. government agencies or large commercial companies. One example is the French Cedex system.
Before postal codes as described here were used, large cities were often divided into postal zones or postal districts, usually numbered from 1 upwards within each city. The newer postal code systems often incorporate the old zone numbers, as with London postal district numbers, for example. Ireland still uses postal district numbers in Dublin. In New Zealand, Auckland, Wellington and Christchurch were divided into postal zones, but these fell into disuse, and have now become redundant as a result of a new postcode system being introduced.
Some postal code system, like the one of Ecuador and Costa Rica show an exact agreement with the hierarchy of the administrative country subdivisions.
Format of 6 digit numeric (8 digit alphanumeric) postal codes in Ecuador, introduced in December 2007: ECAABBCC
Format of 5 digit numeric Postal codes in Costa Rica, introduced in 2007: ABBCC
In Costa Rica these codes are also used by the National Institute for Statistics and Census (INSEC).
The first two digits of the postal codes in Turkey correspond to the provinces and each province has assigned only one number. They are the same for them as in ISO 3166-2:TR.[9]
The first two digits of the postal codes in Vietnam indicate a province. Some provinces have one, other have several two digit numbers assigned. The numbers differ from the number used in ISO 3166-2:VN.
In France the numeric code for the departments is used in the first digits of the postal code, except for the two departments in Corsica that have codes 2A and 2B and use 20 as postal code. Furthermore the codes are only the codes for the department in charge of delivery of the post, so it can be that a location in one department has a postal code starting with the number of a neighbouring department.
The first digit of the postal codes in the United States defines an area including several states. From the first three digits (with some exceptions), one can deduce the state.
The first two digits of the postal codes in Germany define areas independent from administrative regions. The coding space of the first digit is fully used (0-9); that of the first two combined is utilized to 89%, i.e., there are 89 postal zones defined. Zone 11 is non-geographic.
The UK post designed the postal codes in the United Kingdom mostly for efficient distribution. Nevertheless, with time, people associated codes with certain areas, leading certain people wanting or not wanting to have a certain code. See also postcode lottery.
Postal codes in the Netherlands are alphanumeric, consisting of four digits followed by a space and two letters (NNNN AA). Adding the house number to the postcode will identify the address, making the street name and town name redundant. For example: 2597 GV 75 will direct a postal delivery to the International School of The Hague.
Other countries allow equally precise coding. For example, in the United States, the delivery point is typically derived from the last two digits of the house number and thus (at least theoretically) allows an unambiguous identification of every address in the country.
For domestic properties the postcode refers to up to 100 properties in contiguous proximity (e.g. a short section of a populous road, or a series of less populous neighbouring roads). The postcode plus the number or name of a property is not always unique, particularly in rural areas. For example GL20 8NX/1 might refer to either 1 Frampton Cottages or 1 Frampton Farm Cottages, roughly half a kilometre apart. The postcode plus the first line of the address, however, is always unique (except where sub-properties occurs).
Structure is alphanumeric with the following six valid permutations, as defined by BS 7666:
A9 9AA A9A 9AA A99 9AA AA9 9AA AA9A 9AA AA99 9AA
There are always two halves: the separation between outward and inward postcodes is indicated by one space.
The outward postcode covers a unique area and has two parts which may in total be two three or four characters in length. A postcode area of one or two letters, followed by one or two numbers, followed in some parts of London by a letter.
The outward postcode and the leading numeric of the inward postcode in combination forms a postal sector, and this usually corresponds to a couple of thousand properties.
Larger businesses and isolated properties such as farms may have a unique postcode. Extremely large organisations such as larger government offices or bank headquarters may have multiple postcodes for different departments.
There are about 100 postcode areas ranging widely in size from BT which covers the whole of Northern Ireland to ZE for Shetland. Postcode areas may also cross national boundaries, such as SY which covers a large, predominantly rural area from Shrewsbury and Ludlow in Shropshire, England, through to the eastern Welsh town of Welshpool, Powys in Wales to the seaside town of Aberystwyth, Ceredigion on Wales' west coast.
Guernsey, Jersey and the Isle of Man are part of the UK postcode system. They use the scheme AAN NAA, in which the first two letters are a unique code (GY, JE and IM respectively).
Seven British overseas territories use nine postal codes: three for Saint Helena, Ascension and Tristan da Cunha, and one apiece for the others. Note that the former has two ISO 3166-1 alpha-2 country codes, and the British Antarctic Territory has none, so the number of ISO codes is seven.
Two other British areas have their own systems, and use the ISO 3166-1 alpha-2 prefix:
French overseas territories use the five-digit French postal code system, each code starting with the three letter department identifier. Monaco also uses the French system.
Italy, San Marino and Vatican City use one system. Liechtenstein and Switzerland use one system. Slovakia and the Czech Republic base their systems on the codes of Czechoslovakia, their ranges not overlapping.
In Finland the special postal code 99999 is for Korvatunturi, the place where Santa Claus (Joulupukki in Finnish) is said to live.
In Greenland the postal code 2412 is for Julemanden (Santa Claus)
In Canada the amount of mail sent to Santa Claus increased every Christmas, up to the point that Canada Post decided to start an official Santa Claus letter-response program in 1983. Approximately one million letters come in to Santa Claus each Christmas, including from outside of Canada, and all of them are answered in the same languages in which they are written.[10] Canada Post introduced a special address for mail to Santa Claus, complete with its own postal code:
In the United Kingdom, the non-conforming postal code GIR 0AA was used for the National Girobank until its closure in 2003.[11]
| Country | Introduced | ISO | Format | Note |
|---|---|---|---|---|
| Afghanistan | AF | - no codes - | ||
| Åland Islands | AX | NNNNN | With Finland, first two numbers are 22. | |
| Albania | AL | NNNN | ||
| Algeria | DZ | NNNNN | First two as in ISO 3166-2:DZ | |
| Andorra | 2004 | AD | CCNNN | |
| Angola | AO | - no codes - | ||
| Argentina | 1974, modified 1999 | AR | 1974-1998 NNNN; From 1999 ANNNNAAA | Codigo Postal Argentino (CPA), where A is the province code as in ISO 3166-2:AR |
| American Samoa | 1963-07-01 | AS | NNNNN | U.S. ZIP codes |
| Armenia | 2006-04-01 | AM | NNNN | |
| Ascension island | AC | AAAANAA one code: ASCN 1ZZ | UK territory, but not UK postcode | |
| Australia | 1967 | AU | NNNN | |
| Austria | 1966 | AT | NNNN | |
| Azerbaijan | AZ | CCNNNN | ||
| Bangladesh | BD | NNNN | ||
| Barbados | BB | CCNNNNN | ||
| Belarus | BY | NNNNNN | ||
| Belgium | BE | NNNN | First number indicates the province. (not completely correct) | |
| Belize | BZ | - no codes - | ||
| Benin | BJ | - no codes - | ||
| Bosnia and Herzegovina | BA | NNNNN | ||
| Brazil | 1972 | BR | NNNNN | Código de Endereçamento Postal (CEP) |
| Brazil | 1992 | BR | NNNNNNNN (NNNNN-NNN) | |
| British Indian Ocean Territory | IO | AAAANAA one code: BIQQ 1ZZ | UK territory, but not UK postcode | |
| British Virgin Islands | VG | CCNNNN | ||
| Brunei | BN | AANNNN | ||
| Bulgaria | 1975 | BG | NNNN | |
| Cambodia | KH | NNNNN | ||
| Canada | 1971–1975 | CA | ANA NAN | The system was gradually introduced starting in April 1971 in Ottawa |
| Cape Verde | CV | NNNN | The first digit indicates the island. | |
| Chile | CL | NNNNNNN (NNN-NNNN) | ||
| China | CN | NNNNNN | ||
| Colombia | CO | NNNNNN | First NN = 32 departments [12] | |
| Costa Rica | 2007-03 | CR | NNNNN | First codes the provinces, next two the canton, last two the district. |
| Croatia | HR | NNNNN | ||
| Cyprus | 1994-10-01 | CY | NNNN | |
| Czech Republic | 1973 | CZ | NNNNN (NNN NN) | with Slovak Republic, Poštovní směrovací číslo (PSČ) - postal routing number |
| Denmark | 1967-09-20 | DK | NNNN | Numbering follows the dispatch of postal trains from Copenhagen.[13] |
| Ecuador | 2007-12 | EC | CCNNNNNN | |
| Egypt | EG | NNNNN | ||
| Estonia | EE | NNNNN | ||
| Falkland Islands | FK | AAAANAA one code: FIQQ 1ZZ | UK territory, but not UK postcode | |
| Faroe Islands | FO | NNN | self-governing territory within the Kingdom of Denmark, but not Danish postcode | |
| Finland | 1971 | FI | NNNNN | |
| France | 1972 | FR | NNNNN | First mostly as in ISO 3166-2:FR. |
| Georgia | GE | NNNN | ||
| Germany | 1941-07-25 | -- | NN | Postleitzahl (PLZ) |
| Germany | 1962 | DE | NNNN | Postleitzahl (PLZ) |
| Germany | 1993 | DE | NNNNN | Postleitzahl (PLZ) |
| Greece | 1983 | GR | NNNNN | |
| Guam | 1963-07-01 | GU | NNNNN | U.S. ZIP codes |
| Guernsey | 1993 | GG | AAN NAA, AANN NAA | UK-format postcode (first two letters are always GY not GG) |
| Hong Kong | HK | - no codes - | ||
| Hungary | 1973 | HU | NNNN | |
| Iceland | IS | NNN | ||
| India | 1972-08-15 | IN | NNNNNN, NNN NNN |
Postal Index Number (PIN) |
| Indonesia | ID | NNNNN | Kode Pos | |
| Iran | IR | NNNNN-NNNNN | کد پستی | |
| Iraq | 2004 | IQ | NNNNN | |
| Ireland | IE | - no codes - | Alphanumeric system planned, however no known rollout date | |
| Isle of Man | 1993 | IM | CCN NAA, CCNN NAA | UK-format postcode |
| Israel | IL | NNNNN | ||
| Italy | 1967 | IT | NNNNN | Codice di Avviamento Postale (CAP) |
| Japan | 1968 | JP | NNNNNNN (NNN-NNNN) | |
| Jersey | 1994 | JE | CCN NAA | UK-format postcode |
| Kazakhstan | KZ | NNNNNN | Reference:[14] | |
| Latvia | LV | CC-NNNN | ||
| Liechtenstein | 1964 | LI | NNNN | With Switzerland, ordered from west to east |
| Lithuania | LT | NNNNN | References: http://www.post.lt/en/?id=421 http://www.post.lt/en/?id=271 | |
| Luxembourg | LU | NNNN | References: http://www.upu.int/post_code/en/countries/LUX.pdf | |
| Macau | MO | - no codes - | ||
| Malaysia | MY | NNNNN | ||
| Malta | MT | AAANNNN (AAA NNNN) | Kodiċi Postali | |
| Marshall Islands | 1963-07-01 | MH | NNNNN | U.S. ZIP codes |
| Mexico | MX | NNNNN | ||
| Micronesia | 1963-07-01 | FM | NNNNN | U.S. ZIP codes |
| Moldova | MD | CCNNNN (CC-NNNN) | ||
| Monaco | 1972 | MC | 980NN | Similar to France, except when sending a letter from abroad, the address must carry the country name. |
| Montenegro | ME | NNNNN | ||
| Morocco | 1997-01-01 | MA | NNNNN | |
| Netherlands | 1977 | NL | NNNN AA | Postcode |
| New Zealand | 2008-06 | NZ | NNNN | Postcode |
| Nigeria | NI | NNNNNN | ||
| Northern Mariana Islands | 1963-07-01 | MP | NNNNN | U.S. ZIP codes |
| Norway | 1968-03-18 | NO | NNNN | From south to north |
| Palau | 1963-07-01 | PW | NNNNN | U.S. ZIP codes |
| Panama | PA | NNNNNN | ||
| Pakistan | PK | NNNNNN | ||
| Paraguay | PY | NNNN | ||
| Peru | PE | Alphanumeric | New National Postal Code system to be implemented in February 2011[15][16] | |
| Philippines | PH | NNNN | ||
| Pitcairn Islands | PN | AAAANAA one code: PCRN 1ZZ | UK territory, but not UK postcode | |
| Poland | 1973 | PL | NNNNN (NN-NNN) | |
| Portugal | 1976 | NNNN | ||
| Portugal | 1994 | PT | NNNN-NNN (NNNN NNN) | |
| Puerto Rico | 1963-07-01 | PR | NNNNN | U.S. ZIP codes |
| Romania | 2003-05-01 | RO | NNNNNN | |
| Russia | 1971 | RU | NNNNNN | |
| San Marino | SM | NNNNN | With Italy, uses a five-digit numeric CAP of Emilia Romagna | |
| Serbia | 2005-01-01 | RS | NNNNN | Poshtanski adresni kod (PAK) |
| Singapore | 1950 | NN | ||
| Singapore | 1979 | NNNN | ||
| Singapore | 1995 | SG | NNNNNN | |
| Slovakia | 1973 | SK | NNNNN (NNN NN) | with Czech Republic from west to east, Poštové smerovacie číslo (PSČ) - postal routing number |
| Slovenia | SI | CCNNNN (CC-NNNN) | ||
| South Africa | 1975 | ZA | NNNN | |
| South Georgia and the South Sandwich Islands | GS | AAAANAA one code: SIQQ 1ZZ | UK territory, but not UK postcode | |
| South Korea | KR | NNNNNN (NNN-NNN) | ||
| Spain | 1976 | ES | NNNNN | First two indicate the province, range 01-52 |
| Sri Lanka | LK | NNNNN | Reference: http://mohanjith.net/ZIPLook/ | |
| Sweden | 1968-05-12 | SE | NNNNN (NNN NN) | |
| Switzerland | 1964 | CH | NNNN | With Liechtenstein, ordered from west to east |
| Taiwan | TW | NNNNN | includes some territories administrated by Japan | |
| Thailand | 1982-02-25 | TH | NNNNN | The first two specify the province, numbers as in ISO 3166-2:TH, the third and fourth digits specify a district (amphoe) |
| Tunisia | TN | NNNN | ||
| Turks and Caicos Islands | TC | AAAANAA one code: TKCA 1ZZ | UK territory, but not UK postcode | |
| Turkey | TR | NNNNN | The first two specify the province as in ISO 3166-2:TR | |
| Ukraine | UA | NNNNN | ||
| United Kingdom | 1959–1974 | GB | A(A)N(A/N)NAA (A[A]N[A/N] NAA) | Postcode, letters before the first number identify a town or district. AN NAA, ANN NAA, ANA NAA, AAN NAA, AANN NAA, AANA NAA. Complex as incorporates early non-systematic postal districts. |
| United States | 1963-07-01 | US | NNNNN (optionally NNNNN-NNNN or NNNNN-NNNNNN) | ZIP code |
| U.S. Virgin Islands | 1963-07-01 | VI | NNNNN | U.S. ZIP codes |
| Vatican | VA | NNNNN | with Italy, uses a five-digit numeric CAP of Rome | |
| Vietnam | VN | NNNNNN | First two indicate a province |
While postal codes were introduced to expedite the delivery of mail, they are very useful tools for several other purposes, particularly in countries where codes are very fine-grained and identify just a few addresses. Among uses are:
The availability of postal code information has significant economic advantages. In some countries, the postal authorities charge for access to the code database. As of January 2010[update], the United Kingdom Government is consulting on whether to waive licensing fees for some geographical data sets (to be determined) related to UK postcodes.