.gb

---

title: ".gb" type: doc version: 1 created: 2026-02-28 author: "Wikipedia contributors" status: active scope: public tags: ["country-code-top-level-domains", "domain-names-of-the-united-kingdom", "internet-properties-established-in-1985", "1985-establishments-in-the-united-kingdom"] description: "Reserved Internet country-code top level domain for the United Kingdom" topic_path: "geography/united-kingdom" source: "https://en.wikipedia.org/wiki/.gb" license: "CC BY-SA 4.0" wikipedia_page_id: 0 wikipedia_revision_id: 0

::summary Reserved Internet country-code top level domain for the United Kingdom ::

::data[format=table title="Infobox Top level domain"]

Field	Value
name	.gb
background	#CCF
introduced	24 July 1985
type	Country code top-level domain
status	Unused (reserved)
actualuse	Fallen into disuse in favour of .uk
restrictions	No registrations presently being taken
structure	name.gb, Government Websites assigned as .hmg.gb
intendeduse	Entities connected with Great Britain (the United Kingdom)
registry	JANET (Jisc)
::

|name=.gb |background=#CCF |introduced=24 July 1985 |type=Country code top-level domain |status=Unused (reserved) |actualuse=Fallen into disuse in favour of .uk |restrictions=No registrations presently being taken |structure=name.gb, Government Websites assigned as .hmg.gb |document= |disputepolicy= |website= |image= |intendeduse=Entities connected with Great Britain (the United Kingdom) |registry=JANET (Jisc)

.gb is a reserved Internet country code top-level domain (ccTLD) for the United Kingdom, derived from Great Britain.

The domain was introduced with RFC 920 in October 1984 that set out the creation of ccTLD generally using country codes derived from the corresponding two-letter code in the ISO 3166-1 list. However, the .uk domain had been created separately a few months before the compilation of this list. Consequently, .gb was never widely used. It is no longer possible to register under this domain.

.gb was used for a number of years, mainly by British government organisations and commercial e-mail services using X.400-based e-mail infrastructure. This simplified translating between DNS domains and X.400 addresses, which used "GB" as a country code.

With the demise of X.400 e-mail and IANA's general aim of one TLD per country, use of .gb declined; the domain remains in existence, but it is not currently open to new domain registrations.

As of 2025, there are at least three subdomains resolving through DNS (although none serve a web page or use): hermes.dra.hmg.gb, delos.dra.hmg.gb, and dfhnet.dra.hmg.gb. They were originally owned by the Defence Research Agency, which became the Defence Evaluation and Research Agency in 1995 and was split into QinetiQ and the Defence Science and Technology Laboratory in 2001; the websites became defunct some time thereafter.

, Central Digital and Data Office's intention was to inform ICANN early in 2023 that the UK wishes to retire the .gb ccTLD.

References

References

1. J. Postel and J. Reynolds. (October 1984). "RFC 920: Domain Requirements". Network Working Group.
2. Milton Mueller. (2002). "Ruling the Root: Internet Governance and the Taming of Cyberspace". [[MIT Press]].
3. Crepin-Leblond, Olivier M. J.. (2003). "International E-mail Accessibility".
4. "DNS lookup for hermes.dra.hmg.gb".
5. (November 1994). "Computer Security – ESORICS 94". [[Springer-Verlag]].
6. "DERA". DERA.
7. (15 November 2022). "Is it time to retire the .gb top level domain?". UK Government.

::callout[type=info title="Wikipedia Source"] This article was imported from Wikipedia and is available under the Creative Commons Attribution-ShareAlike 4.0 License. Content has been adapted to SurfDoc format. Original contributors can be found on the article history page. ::