Internet top-level domain

Country code TLDs

Two-letter top-level domains are assigned to countries and dependent teritories by ICANN. Main criteria for ICANN is ISO country codes list, but ICANN and ISO lists differ a little.

As of 13.02.2019 ISO list contains 249 officially assigned codes.

As of 13.02.2019 ICANN's IANA Root Zone Database contains 255 two-latin-letters country-code domains, including 249 ISO-assigned codes + AC (Ascension - while it is part of Saint Helena, Ascension and Tristan da Cunha territory in SH ISO code), AN (former Netherlands Antilles, divided into BQ, CW and SX), EU (European Union), SU (Soviet Union), TP (former Portuguese Timor) and UK (United Kingdom, along with GB for Great Britain - domain GB is Reserved and works for only one 2nd-level domain name hmg.gb - stands for 'Her Majesty Government' - with several subdomains but no websites on them).

248 domains are online. Domains BL (Saint Barthélemy), BQ (Bonaire, Sint Eustatius and Saba), EH (Western Sahara), MF (Saint Martin) and UM (U.S. Minor Outlying Islands) are marked as Not assigned. AN and TP marked as Retired.

ISO codes

ISO codes are based on United Nations Statistics Division list. UNSD list includes as separate entries Sark island (since 2011) and Channel Islands.

12 ISO codes are exceptionally reserved at requests of countries and organisations:

AC Ascension Island
CP Clipperton Island
DG Diego Garcia
EA Ceuta and Melilla
EU European Union
EZ (European OTC derivatives)
FX France, Metropolitan
IC Canary Islands
SU USSR
TA Tristan da Cunha
UK United Kingdom
UN United Nations

Reserved codes AC, EU, SU and UK are delegated as Internet TLDs.

7 ISO codes are transitionally reserved for 50 years after renaming of countries or dissolution of federations and dependent territories:

BU Burma                 Reserved from 1989-12 to 2039-12. New country name: Myanmar                   MM
NT Neutral Zone          Reserved from 1993-07 to 2043-07. Divided between Iraq and Saudi Arabia     IQ+SA
ZR Zaire                 Reserved from 1997-07 to 2047-07. New country name: Congo (Kinshasa)          CD
TP East Timor            Reserved from 2002-05 to 2052-05. New country name: Timor-Leste               TL
YU Yugoslavia            Reserved from 2003-07 to 2053-07. New country name: Serbia and Montenegro     CS
CS Serbia and Montenegro Reserved from 2006-09 to 2056-09. Divided to Serbia and Montenegro          RS+ME
AN Netherlands Antilles  Reserved from 2010-12 to 2060-12. Divided (see below)                      BQ+CW+SX

.AN deleted by ISO on 2010-12-15/2011-12-13 - and is still transitionally reserved to Netherlands Antilles (divided into: Bonaire, Sint Eustatius and Saba - BQ, Curaçao - CW and Sint Maarten - SX).