A country code top-level domain (ccTLD) is an

Internet The Internet (or internet) is the Global network, global system of interconnected computer networks that uses the Internet protocol suite (TCP/IP) to communicate between networks and devices. It is a internetworking, network of networks ...

top-level domain A top-level domain (TLD) is one of the domain name, domains at the highest level in the hierarchical Domain Name System of the Internet after the root domain. The top-level domain names are installed in the DNS root zone, root zone of the nam ...

generally used or reserved for a

country A country is a distinct part of the world, such as a state, nation, or other political entity. When referring to a specific polity, the term "country" may refer to a sovereign state, state with limited recognition, constituent country, ...

, sovereign state, or

dependent territory A dependent territory, dependent area, or dependency (sometimes referred as an external territory) is a territory that does not possess full political independence or sovereignty as a sovereign state and remains politically outside the controll ...

identified with a

country code A country code is a short alphanumeric identification code for countries and dependent areas. Its primary use is in data processing and communications. Several identification systems have been developed. The term ''country code'' frequently re ...

. All

ASCII ASCII ( ), an acronym for American Standard Code for Information Interchange, is a character encoding standard for representing a particular set of 95 (English language focused) printable character, printable and 33 control character, control c ...

ccTLD identifiers are two letters long, and all two-letter top-level domains are ccTLDs. In 2018, the

Internet Assigned Numbers Authority The Internet Assigned Numbers Authority (IANA) is a standards organization that oversees global IP address allocation, Autonomous system (Internet), autonomous system number allocation, DNS root zone, root zone management in the Domain Name Syste ...

(IANA) began implementing

internationalized country code top-level domain An internationalized country code top-level domain is a top-level domain in the Domain Name System (DNS) of the Internet. IDN ccTLDs are specially encoded domain names that are displayed in an end user application, such as a web browser, in the ...

s, consisting of language-native characters when displayed in an end-user application. Creation and delegation of ccTLDs is described in RFC 1591, corresponding to ISO 3166-1 alpha-2 country codes. While gTLDs have to obey international regulations, ccTLDs are subjected to requirements that are determined by each country's domain name regulation corporation. With over 150 million domain name registrations as of 2022, ccTLDs make up about 40% of the total domain name industry. Country code extension applications began in 1985. The registered country code extensions in that year included .us (United States), .uk (United Kingdom) and .il (Israel). The registered country code extensions in 1986 included .au (Australia), .de (Germany), .fi (Finland), .fr (France), .is (Iceland), .jp (Japan), .kr (South Korea), .nl (Netherlands) and .se (Sweden). The registered country code extensions in 1987 included .nz (New Zealand), .ch (Switzerland) and .ca (Canada). The registered country code extensions in 1988 included .ie (Ireland) .it (Italy), .es (Spain) and .pt (Portugal). The registered country code extensions in 1989 included .in (India) and .yu (Yugoslavia). In the 1990s, .cn (People's Republic of China) and .ru (Russian Federation) were first registered. There are 308 delegated ccTLDs. The .cn, .tk, .de, .uk, .nl and .ru ccTLDs contain the highest number of domains. The top ten ccTLDs account for more than five-eighths of registered ccTLD domains. There were about 153 million ccTLD domains registered at the end of March 2022.

Delegation and management

IANA is responsible for determining an appropriate trustee for each ccTLD. Administration and control are then delegated to that trustee, which is responsible for the policies and operation of the domain. The current delegation can be determined from IANA's list of ccTLDs. Individual ccTLDs may have varying requirements and fees for registering subdomains. There may be a local-presence requirement (for instance, citizenship or other connection to the ccTLD), as, for example, the American ( us),

Japan Japan is an island country in East Asia. Located in the Pacific Ocean off the northeast coast of the Asia, Asian mainland, it is bordered on the west by the Sea of Japan and extends from the Sea of Okhotsk in the north to the East China Sea ...

ese ( jp),

Canadian Canadians () are people identified with the country of Canada. This connection may be residential, legal, historical or cultural. For most Canadians, many (or all) of these connections exist and are collectively the source of their being ''C ...

( ca), French ( fr) and German ( de) domains, or registration may be open.

History

The first registered ccTLD was .us, which was registered in 1985. Later ccTLDs registered in that year included .uk and .il. Then, .au, .de, .fi, .fr, .is, .jp, .kr, .nl and .se were also registered in 1986. In 1987, .nz, .ch, .my and .ca were registered. Later on, in 1988, .ie, .it, .es and .pt were also registered.

Lists

As of 20 May 2017, there were 255 country-code top-level domains, purely in the Latin alphabet, using two-character codes. The number was 316 , with the addition of internationalized domains.

Latin Character ccTLDs

: ;Overview of Latin-character country-code TLDs After clicking a letter, possibly scroll up to see rows hidden by sticky table headers. ;Table Notes:

Internationalized ccTLDs

Proposed internationalized ccTLDs

Internationalised domain names have been proposed for

and

Libya Libya, officially the State of Libya, is a country in the Maghreb region of North Africa. It borders the Mediterranean Sea to the north, Egypt to Egypt–Libya border, the east, Sudan to Libya–Sudan border, the southeast, Chad to Chad–L ...

Relation to ISO 3166-1

Unused ISO 3166-1 codes

Almost all current ISO 3166-1 codes have been assigned and do exist in DNS. However, some of these are effectively unused. In particular, the ccTLDs for the Norwegian dependency Bouvet Island ( bv) and the designation Svalbard and Jan Mayen ( sj) do exist in DNS, but no subdomains have been assigned, and it is Norid policy to not assign any at present. Two French territories— bl (

Saint Barthélemy Saint Barthélemy, officially the Collectivité territoriale de Saint-Barthélemy, also known as St. Barts (English) or St. Barth (French), is an overseas collectivity of France in the Caribbean. The island lies about southeast of the island ...

) and mf ( Saint Martin)— await local assignment by France's government. The code eh, although eligible as ccTLD for

Western Sahara Western Sahara is a territorial dispute, disputed territory in Maghreb, North-western Africa. It has a surface area of . Approximately 30% of the territory () is controlled by the Sahrawi Arab Democratic Republic (SADR); the remaining 70% is ...

, has never been assigned and does not exist in DNS. Only one subdomain is still registered in gb (ISO 3166-1 for the

United Kingdom The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Northwestern Europe, off the coast of European mainland, the continental mainland. It comprises England, Scotlan ...

), and no new registrations are being accepted for it. Sites in the United Kingdom generally use uk (see below). The former .um ccTLD for the U.S. Minor Outlying Islands was removed in April 2008. Under RFC 1591 rules, .um is eligible as a ccTLD on request by the relevant governmental agency and local Internet user community.

ASCII ccTLDs not in ISO 3166-1

Several ASCII ccTLDs are in use that are not ISO 3166-1 two-letter codes. Some of these codes were specified in older versions of the ISO list. * uk (United Kingdom): The ISO 3166-1 code for the United Kingdom is GB (Great Britain). However, the

JANET Janet may refer to: Names * Janet (given name) Surname * Charles Janet (1849–1932), French engineer, inventor and biologist, known for the Left Step periodic table * Jules Janet (1861–1945), French psychologist and psychotherapist * Maur ...

network had already selected uk as a top-level identifier for its pre-existing Name Registration Scheme, and this was incorporated into the DNS root. gb was assigned with the intention of a transition, but this never occurred and the use of uk is now entrenched. * su This obsolete ISO 3166 code for the

Soviet Union The Union of Soviet Socialist Republics. (USSR), commonly known as the Soviet Union, was a List of former transcontinental countries#Since 1700, transcontinental country that spanned much of Eurasia from 1922 until Dissolution of the Soviet ...

was assigned when the Soviet Union still existed; moreover, new su registrations are accepted. * ac (

Ascension Island Ascension Island is an isolated volcanic island, 7°56′ south of the Equator in the Atlantic Ocean, South Atlantic Ocean. It is about from the coast of Africa and from the coast of South America. It is governed as part of the British Overs ...

): This code is a vestige of IANA's decision in 1996 to allow the use of codes reserved in the

ISO 3166-1 alpha-2 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 ...

reserve list for use by the Universal Postal Union. The decision was later reversed, with Ascension Island now the sole outlier. (Three other ccTLDs, gg (

Guernsey Guernsey ( ; Guernésiais: ''Guernési''; ) is the second-largest island in the Channel Islands, located west of the Cotentin Peninsula, Normandy. It is the largest island in the Bailiwick of Guernsey, which includes five other inhabited isl ...

), im (

Isle of Man The Isle of Man ( , also ), or Mann ( ), is a self-governing British Crown Dependency in the Irish Sea, between Great Britain and Ireland. As head of state, Charles III holds the title Lord of Mann and is represented by a Lieutenant Govern ...

) and je (

Jersey Jersey ( ; ), officially the Bailiwick of Jersey, is an autonomous and self-governing island territory of the British Islands. Although as a British Crown Dependency it is not a sovereign state, it has its own distinguishing civil and gov ...

) also fell under this category from 1996 until they received corresponding ISO 3166 codes in March 2006.) * eu (

European Union The European Union (EU) is a supranational union, supranational political union, political and economic union of Member state of the European Union, member states that are Geography of the European Union, located primarily in Europe. The u ...

): On September 25, 2000,

ICANN The Internet Corporation for Assigned Names and Numbers (ICANN ) is a global multistakeholder group and nonprofit organization headquartered in the United States responsible for coordinating the maintenance and procedures of several dat ...

decided to allow the use of any two-letter code in the ISO 3166-1 reserve list that is reserved for all purposes. Only EU currently meets this criterion. Following a decision by the EU's Council of Telecommunications Ministers in March 2002, progress was slow, but a registry (named EURid) was chosen by the

European Commission The European Commission (EC) is the primary Executive (government), executive arm of the European Union (EU). It operates as a cabinet government, with a number of European Commissioner, members of the Commission (directorial system, informall ...

, and criteria for allocation set: ICANN approved eu as a ccTLD, and it opened for registration on 7 December 2005 for the holders of prior rights. Since 7 April 2006, registration is open to all in the European Economic Area.

Historical ccTLDs

ccTLDs may be removed if that country ceases to exist. There are three ccTLDs that have been deleted after the corresponding 2-letter code was withdrawn from ISO 3166-1: cs (for

Czechoslovakia Czechoslovakia ( ; Czech language, Czech and , ''Česko-Slovensko'') was a landlocked country in Central Europe, created in 1918, when it declared its independence from Austria-Hungary. In 1938, after the Munich Agreement, the Sudetenland beca ...

), zr (for

Zaire Zaire, officially the Republic of Zaire, was the name of the Democratic Republic of the Congo from 1971 to 18 May 1997. Located in Central Africa, it was, by area, the third-largest country in Africa after Sudan and Algeria, and the 11th-la ...

) and tp (for

East Timor Timor-Leste, also known as East Timor, officially the Democratic Republic of Timor-Leste, is a country in Southeast Asia. It comprises the eastern half of the island of Timor, the coastal exclave of Oecusse in the island's northwest, and ...

). There may be a significant delay between withdrawal from ISO 3166-1 and deletion from the DNS; for example, ZR ceased to be an ISO 3166-1 code in 1997, but the zr ccTLD was not deleted until 2001. Other ccTLDs corresponding to obsolete ISO 3166-1 codes have not yet been deleted. In some cases they may never be deleted due to the amount of disruption this would cause for a heavily used ccTLD. In particular, the Soviet Union's ccTLD su remains in use more than twenty years after SU was removed from ISO 3166-1. The historical country codes dd for the

German Democratic Republic East Germany, officially known as the German Democratic Republic (GDR), was a country in Central Europe from Foundation of East Germany, its formation on 7 October 1949 until German reunification, its reunification with West Germany (FRG) on ...

and yd for

South Yemen South Yemen, officially the People's Democratic Republic of Yemen, abbreviated to Democratic Yemen, was a country in South Arabia that existed in what is now southeast Yemen from 1967 until Yemeni unification, its unification with the Yemen A ...

were eligible for a ccTLD, but not allocated; see also de and ye. The temporary reassignment of country code cs (

Serbia and Montenegro The State Union of Serbia and Montenegro or simply Serbia and Montenegro, known until 2003 as the Federal Republic of Yugoslavia and commonly referred to as FR Yugoslavia (FRY) or simply Yugoslavia, was a country in Southeast Europe locate ...

) until its split into rs and me (

Serbia , image_flag = Flag of Serbia.svg , national_motto = , image_coat = Coat of arms of Serbia.svg , national_anthem = () , image_map = , map_caption = Location of Serbia (gree ...

and

Montenegro , image_flag = Flag of Montenegro.svg , image_coat = Coat of arms of Montenegro.svg , coa_size = 80 , national_motto = , national_anthem = () , image_map = Europe-Mont ...

, respectively) led to some controversies about the stability of ISO 3166-1 country codes, resulting in a second edition of ISO 3166-1 in 2007 with a guarantee that retired codes will not be reassigned for at least 50 years, and the replacement of RFC 3066 by RFC 4646 for country codes used in language tags in 2006. The previous ISO 3166-1 code for

Yugoslavia , common_name = Yugoslavia , life_span = 1918–19921941–1945: World War II in Yugoslavia#Axis invasion and dismemberment of Yugoslavia, Axis occupation , p1 = Kingdom of SerbiaSerbia , flag_p ...

, YU, was removed by ISO on 23 July 2003, but the yu ccTLD remained in operation. Finally, after a two-year transition to Serbian rs and Montenegrin me, the .yu domain was phased out in March 2010. Australia was originally assigned the oz country code, which was later changed to au with the .oz domains moved to .oz.au.

Internationalized ccTLDs

(IDN ccTLD) is a top-level domain with a specially encoded domain name that is displayed in an end user application, such as a

web browser A web browser, often shortened to browser, is an application for accessing websites. When a user requests a web page from a particular website, the browser retrieves its files from a web server and then displays the page on the user's scr ...

, in its native language script or a non-alphabetic

writing system A writing system comprises a set of symbols, called a ''script'', as well as the rules by which the script represents a particular language. The earliest writing appeared during the late 4th millennium BC. Throughout history, each independen ...

, such as

Latin script The Latin script, also known as the Roman script, is a writing system based on the letters of the classical Latin alphabet, derived from a form of the Greek alphabet which was in use in the ancient Greek city of Cumae in Magna Graecia. The Gree ...

(.us, .uk and .br),

Indic script The Brahmic scripts, also known as Indic scripts, are a family of abugida writing systems. They are used throughout South Asia, Southeast Asia and parts of East Asia. They are descended from the Brahmi script of ancient India and are used b ...

(.) and Korean script (.), etc. IDN ccTLDs are an application of the

internationalized domain name An internationalized domain name (IDN) is an Internet domain name that contains at least one label displayed in software applications, in whole or in part, in non-Latin script or alphabet or in the Latin alphabet-based characters with diacrit ...

(IDN) system to top-level Internet domains assigned to countries, including the United Kingdom, or independent geographic regions. ICANN started to accept applications for IDN ccTLDs in November 2009, and installed the first set into the Domain Names System in May 2010. The first set was a group of Arabic names for the countries of Egypt, Saudi Arabia, and the United Arab Emirates. By May 2010, 21 countries had submitted applications to ICANN, representing 11 languages. ICANN requires all potential international TLDs to use at least one letter that does not resemble a Latin letter, or have at least three letters, in an effort to avoid

IDN homograph attack The internationalized domain name (IDN) homograph attack (sometimes written as homoglyph attack) is a method used by malicious parties to deceive computer users about what remote system they are communicating with, by exploiting the fact that man ...

s. Nor shall the international domain name look like another domain name, even if they have different alphabets. Between Cyrillic and Greek alphabets, for example, this could happen.

Generic ccTLDs

Generic Country Code Top-Level Domain or gccTLD refers to those TLDs which are technically "non-restricted ccTLDs" but used like traditional generic TLDs ( gTLDs) rather than "country"-targeted ones. Most of the gccTLDs are primarily used as domain hacks:

Unconventional usage

Lenient registration restrictions on certain ccTLDs have resulted in various domain hacks. Domain names such as I.am, tip.it, start.at and go.to form well-known English phrases, whereas others combine the second-level domain and ccTLD to form one word or one title, creating domains such as blo.gs of

South Georgia and the South Sandwich Islands South Georgia and the South Sandwich Islands (SGSSI) is a British Overseas Territory in the southern Atlantic Ocean. It is a remote and inhospitable collection of islands, consisting of South Georgia and a chain of smaller islands known as the ...

( gs), youtu.be of

Belgium Belgium, officially the Kingdom of Belgium, is a country in Northwestern Europe. Situated in a coastal lowland region known as the Low Countries, it is bordered by the Netherlands to the north, Germany to the east, Luxembourg to the southeas ...

( be), del.icio.us of the

United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

( us), and cr.yp.to of

Tonga Tonga, officially the Kingdom of Tonga, is an island country in Polynesia, part of Oceania. The country has 171 islands, of which 45 are inhabited. Its total surface area is about , scattered over in the southern Pacific Ocean. accordin ...

( to). The .co domain of Colombia has been cited since 2010 as a potential competitor to generic TLDs for commercial use, because it may be an abbreviation for ''company''. Several ccTLDs allow the creation of emoji domains. Some ccTLDs may also be used for typosquatting. The domain ''cm'' of

Cameroon Cameroon, officially the Republic of Cameroon, is a country in Central Africa. It shares boundaries with Nigeria to the west and north, Chad to the northeast, the Central African Republic to the east, and Equatorial Guinea, Gabon, and the R ...

has generated interest due to the possibility that people might miss typing the letter ''o'' for sites in the ''com''.

Commercial use

Some of the world's smallest countries and non-sovereign or colonial entities with their own country codes have opened their TLDs for worldwide commercial use, some of them free like .tk.

References

External links

* * * * * {{DEFAULTSORT:Country Code Top-Level Domain International telecommunications Top-level domains Country codes Domain Name System

Delegation and management

History

Lists

Latin Character ccTLDs

Internationalized ccTLDs

Proposed internationalized ccTLDs

Relation to ISO 3166-1

Unused ISO 3166-1 codes

ASCII ccTLDs not in ISO 3166-1

Historical ccTLDs

Internationalized ccTLDs

Generic ccTLDs

Unconventional usage

Commercial use

See also

References

External links