Key to global trade

ISO 3166 is used in a broad variety of fields of activity – by institutions as well as by private individuals. It consists of three interdependent parts and forms the basis of a coherent system for all types of exchanges (economic, financial, legal, cultural, scientific, etc.) both within and between countries, in combination with the International Standards on :

  • Names of languages – ISO 639, Codes for the representation of names of languages
  • Writing systems – ISO 15924:2004, Information and documentation – Codes for the representation of names of scripts
  • Currencies – ISO 4217:2008, Codes for the representation of currencies and funds.

It is one of the building blocks underpinning globalization and, in particular, communication and exchanges on the Web.

An essential presence

Wikipedia, the most well-known and highly visited online encyclopaedia gives a good estimate of the international penetration of ISO 3166. In Wikipedia, the general presentation of ISO 3166 is available in 36 languages, while Part 1 (ISO 3166-1) relating to country codes is described in 92 languages, Part 2 (ISO 3166-2) relating to country subdivision codes is described in 47 languages, and Part 3 (ISO 3166-3) providing the codes for formerly used names of countries is available in 15 languages. In addition, all articles on countries or country subdivisions (at least in the English version) display the ISO 3166-1 or ISO 3166-2 codes, in the general information box.

A search on the Web also gives an idea of the number of pages mentioning or introducing this three-part standard. For example, a search on Google (as of 14 March 2011) provided 819 000 results for ISO 3166, 886 000 for ISO 3166-1, 3 720 000 for ISO 3166-2 and 35 000 for ISO 3166-3. By way of comparison, there are 852 000 results on ISO 639, 67 000 on ISO 15924 and 237 000 on ISO 4217.

Scale of the applications of ISO 3166

The acceptance which an International Standard has gained within its potential user community can be seen from the number or scale of its applications. The most well-known applications of ISO 3166 are :

  • The Internet Assigned Numbers Authority (IANA) which uses the alpha-2 code (alphabetic 2-character code) to identify the Internet ccTLDs (country code top-level domains) designating all of the domain names assigned to the different countries such as, for instance, “.fr” for France, “.eg” for Egypt or“.jp” for Japan
  • The code elements from ISO 4217, which are based on the ISO 3166-1 alpha-2 code; e.g., USD for US dollar, where US comes from ISO 3166-1.
  • Passport numbers which use the ISO 3166-1 alpha-3 codes as well as a number of alpha-3 codes which are reserved for identifying the country or the authority issuing a machine-readable passport (see Box below).  

Searching the Internet is a good strategy to find many other examples. The following examples encompass a highly diversified range of fields or subject areas from economics to art and culture, through transport and safety, health or international and national organizations. They provide a broader view of the full spectrum of implementations of ISO 3166. Yet, they account for only a small share of the results obtained, and they all relate to a lesser or a greater extent to geolocation features.

Travel documents

Among the many applications of ISO standard for country codes ISO 3166, Codes for the representation of names of countries and their subdivisions, is that of travel documents.

With the growth and proliferation of international travel, the global community required that travel documents and the information they contain be standardized to speed up and increase security of identification checks. Among this was the data stating a person’s origin or nationality

The three-letter code used by the International Civil Aviation Organization (ICAO) adopted by ISO/IEC 7501-1:2008, Identification Cards – Machine Readable Travel Documents – Part 1: Machine Readable Passports, and used by all international machine readable travel documents (MRTD) issuing entities, is intimately linked with the alpha-3 code employed in the first part of ISO 3166-1, Part 1: Country codes.

This ICAO code is not a country code per se (nor completely an alpha-3 code), but can be better described as a quasi alpha-3 code for designation of nationality, place of birth or issuing state/authority. The ICAO code comprises four distinct parts, as follows.

Nationality, place of birth, issuing authority

The first part is Part A – Codes for designation of nationality, place of birth or issuing state/authority. Part A reproduces the complete list of entries and corresponding alpha-3 code elements specified by ISO 3166-1, with a few exceptions. For instance, ICAO’s code for Germany is not the alpha-3 code element “DEU”, as in ISO 3166-1, but the alpha-1 code element “D”.

For the United Kingdom, where ISO 3166-1 provides the alpha-3 code element “GBR”, ICAO’s code system includes the following six additional code elements representing the indicated classifications:

  • GBR (Citizen)
  • GBD (Dependent territories citizen)
  • GBN (National [Overseas])
  • GBO (Overseas citizen)
  • GBP (Protected person)
  • GBS (Subject).

The last five codes mentioned in this list ha ve acquired “exceptionally reserved” status in ISO 3166-1.

UN travel documents

The second part is Part B – Codes for use in United Nations travel documents. Part B contains three entries, which have no counterparts in ISO 3166-1, but which have also acquired exceptionally reserved status in ISO 3166-1:

  • UNO : United Nations organization or one of its officials
  • UNA : Specialized agency of the United Nations or one of its officials
  • UNK : Resident of Kosovo to whom a travel document has been issued by the United Nations Interim Administrative Mission in Kosovo (UNMIK).

Issuing authorities

The third part of the ICAO codes is Part C – Codes for issuing authorities. This part contains the following entries, which have no counterparts in ISO 3166-1:

  • XCC : Designates the Caribbean Community (CARICOM)
  • XOM : Designates the Sovereign Military Order of Malta or one of its emissaries
  • XPO : Designates the International Criminal Police Organisation (INTERPOL).

These code elements may additionally be found in the list of user-reserved code elements in ISO 3166-1.

No defined nationality

The fourth part is Part D – Codes for persons without a defined nationality. Once again, Part D contains codes which have no counterpart in ISO 3166-1, but are listed as user-reserved code elements:

  • XXA : Stateless person
  • XXB : Refugee, as defined in the 1951 Convention Relating to the Status of refugees
  • XXC : Refugee, other than as defined under the code XXB
  • XXX : Person of unspecified nationality whatever the person’s status may be. This category may include a person who is neither Stateless nor a refugee, but who is of unknown nationality and legally residing in the State of issue.

This text is written by Gérard Lang, Chair of the ISO 3166 Maintenance Agency, and Convenor of ISO/TC 46/WG 2, Coding of country names and related entities. It originally appeared in the ICAO MRTD Report, Volume 6, Number 1, 2011. It is reprinted here with the knowledge and permission of ICAO.

From finance to geography

ISO 3166 is widely used in the economic, trade and financial environments. The ISO 3166-1 coding system is used not only for the representation of currencies, but also for the International Bank Account Number (IBAN) and the universal Bank Identifier Code (BIC, often called SWIFT code).  More generally, it is found in online payment systems such as PayPal, Alertpay. The GTAP 7 (Global Trade Analysis Project), a network of researchers whose mission is to improve the quality of the quantitative analysis of global economic issues, not only uses the ISO 3166 alpha-3 codes (alphabetic 3-character code) to identify countries and world regions, but also uses a free X code to designate specific parts of the world.

Similarly, the transportation sector, which facilitates the movement and exchange of goods, uses the ISO 3166 codes for different contexts: i.e., sea transport (NAVTEX maritime safety information system, monitoring stations), European road transport (European Union legislation), transportation of dangerous goods, cross-border movements of hazardous waste, etc., including for the labelling of chemical products.

Geography, cartography and geolocation are some of the major sectors using ISO 3166 for the identification of the code elements of some countries, drawing maps with Google tools, or locating areas on an atlas.

Another widespread use of the standard concerns the geofiltering features applied by countries to the videos and players they use, in order to restrict access to content and reading to some geographical areas, as the world is divided in different zones.

Geolocation is also used to identify, record or register places relating to clients, addresses, job announcements, etc.

Supporting art, culture and the media

Art and archaeology use the ISO 3166 codes and conventions for identification and location purposes.

For example, after the creation of a basic index of place names, Afghanistan’s archaeological sites have been numbered according to the present-day province where they are located, on the basis of ISO 3166-2.

In France, a 3D architectural model project using augmented reality technology, aiming to reconstitute part of the former buildings of the Cluny Abbey, is based on cutting out a number of components identified by a bar code incorporating the FR-071 (for the Saône-et-Loire administrative division in France) code element from ISO 3166-2.

Many libraries have also based their coding system on ISO 3166. In order to facilitate bibliometric measures, the standardization of document descriptions has been proposed, with the coding of the principal author’s country of affiliation based on ISO 3166.

The German National Library (Deutsche Nationalbibliothek, DNB) uses ISO 3166 in its standardized descriptors (Schlagwortnormdatei, SWD). The Website of Arabic libraries (arablibrariannet), and the ABES French Website (Higher Education Bibliographic Association) with respect to metadata relating to electronic theses (TEF), have adopted ISO 3166 for coding the original country of such documents.

In the United Kingdom, libraries (and similar organizations) have an ISIL identifier (International Standard identifier for libraries and related organizations) based on the “ MARC organisation code ” whose uniqueness is ensured by assigning a country code prefix based on ISO 3166-1.

In the cultural and media sectors, organizations as well as individuals often recommend using the ISO 3166 2 codes to identify countries among the embedded metadata. For example, this type of recommendation is found on the Website of an American agency responsible for archiving audiovisual documents, or on the initiative of a private individual for the management of digital photographic materials.

A Market research on the video-on-demand (VoD) carried out in 24 European countries, displays countries in the sequence of the ISO 3166-1 alpha-2 code elements to maintain neutrality in the classification (Switzerland under CH, United Kingdom under GB).

News agencies often assign ISO 3166 code elements to texts and images. Job offers can be posted on the Internet using programmes incorporating the ISO 3166-1 and ISO 3166-2 codes.

An ideal system for IT

A significant number of companies or individuals developing software (database management systems for example) have adopted, among all the tools made available to developers, the ISO 3166 code elements used for identifying countries.

For instance, the “” Website whose official aim is “to help IT specialists and students easily cooperate and share multiple resources” gives under a list of “XHTML tags”, the alpha-2 code elements for countries, languages and scripts.

Another Website provides – as part of the elements required for software localization – under the “Local class” name, the objects for identifying or changing the country and the language used by the computer running the application.

A number of Websites have a search help feature by location in the form of a menu using the ISO 3166 codes or country names (e.g., the European Commission Website).

In order to further promote the use of the standard, and considering that entities are “only” provided in French and English, translation programmes are developed (e.g., in Chinese) for the names of said entities, in order to “internationalize” the ISO 3166 entity names.

From a more global perspective, note that ISO 3166 (and the other codes mentioned at the beginning of this article) is included in the basic information provided by the W3C (World Wide Web Consortium) responsible for promoting compatibility between Web technologies as well as by the Dublin Core (a generic metadata schema for describing digital or physical resources and establishing links with other resources), and which is intended to be used in all projects where countries, languages, and scripts play an essential part.

From the United Nations to stamp collecting

Many international organizations recommend or use ISO 3166. Examples include the United Nations, the United Nations Educational, Scientific and Cultural Organization (UNESCO), the Universal Postal Union (UPU), the United Nations Economic Commission for Europe (UNECE).

National or governmental organizations, e.g., the US Food and Drug Administration and the US Department of Defense, extensively use ISO 3166 sometimes to replace their national coding system (particularly in the USA, or within the Philippine government).

In the security sector, Interpol (the International Criminal Police Organization) uses a Destination Agency Identifier (DAI) which includes an Interpol Country Code based on ISO 3166, in order to communicate fingerprint images to relevant agencies.

In a significant number of scientific fields and disciplines, the ISO 3166 code elements are assigned to country-based objects, products and symbols, such as stamps (philately) or flags (vexillology).

ISO 3166 is also used to identify original place names for genealogical purposes or regional patronymic researches. The case of England provides an interesting anecdote. The ISO 3166-2 codes representing the administrative divisions of this part of the United Kingdom, derived from the British Standard BS 6879, were initially based on the County (or Chapman) Codes established by Dr. Colin Chapman precisely for genealogical searches.

Finally, the health sector (epidemics, disease control, biomedical equipment) uses ISO 3166 code elements in its work.

Living organisms themselves are no exception to the rule, and their identifications refer to ISO 3166 code elements :

  • Animals : horses (Universal equine life number), marine organisms
  • Plants : herbariums, flora, taro species.

Even if the many examples offered in this article only marginally represent the great variety of uses of ISO 3166, they provide an overview of the breadth and scale of its adoption and implementations.

About the author

François Demay is, since 2000, a consultant in lexicography, terminology, and information and language processing. He was Secretary General of the Encyclopaedia Universalis publication from 1965 to 1977. In 1977, he became the Scientific and Technical Editor and subsequently, the Editor-in-Chief of the Larousse dictionaries and reference books. Mr. Demay became special advisor to Larousse’s CEO in 1996 and was seconded to New York on an observation assignment. From 1997 to 2000, he was the Editor-in-Chief of the French version of (Microsoft) Encarta Encyclopedia.