|This article needs additional citations for verification. (January 2011)|
|TLD type||Country code top-level domain|
|Intended use||Entities connected with the
|Actual use||Very popular in UK, especially .co.uk subdomain|
|Registered domains||10,047,549 (March 2012)|
|Registration restrictions||It is prohibited until summer 2014  to register a domain name directly under the ccTLD .uk. No restrictions for .co.uk, .me.uk, and .org.uk; other subdomains have differing restrictions|
|Structure||At third level, beneath generic-category 2nd level domains, except under .sch.uk where registration is at fourth level; no second-level registrations (a few old registrations grandfathered)|
|Dispute policies||DRS Policy|
.uk is the Internet country code top-level domain (ccTLD) for the United Kingdom of Great Britain and Northern Ireland. As of March 2012[update], it is the fourth most popular top-level domain worldwide (after .com, .de and .net), with over 10 million registrations.
In October 1984, RFC 920 set out the creation of ccTLDs generally using country codes derived from the corresponding two-letter code in the ISO 3166-1 list. GB is the UK's ISO 3166 country code. However, the .uk domain had been created separately a few months before the compilation of the ISO-derived list. Consequently, .gb was never widely used and it is no longer possible to register under that domain.
As with other ccTLDs in the early days it was originally delegated to an individual by Jon Postel. In time, it passed to Dr Willie Black at the UK Education and Research Networking Association. Originally, domain requests were emailed, manually screened by and then forwarded to the UK Naming Committee before being processed by UKERNA. Membership of this committee was restricted to a group of high-end ISPs who were part of a formal peering arrangement.
The Naming Committee was organised as a mailing list to which all proposed names were circulated. The members would consider the proposals under a ruleset that insisted that all domain names should be very close if not identical to a registered business name of the registrant. Members of the Naming Committee could object to any name, and if a small number of objections were received, the name was refused.
By the mid-1990s the growth of the Internet, and particularly the advent of the World Wide Web was pushing requests for domain name registrations up to levels that were not manageable by a group of part-time voluntary managers. Oliver Smith of Demon Internet forced the issue by providing the committee with a series of automated tools, called the "automaton", which formalised and automated the naming process end to end. This allowed many more registrations to be processed far more reliably and rapidly, and inspired individuals such as Ivan Pope to explore more entrepreneurial approaches to registration.
Various plans were put forward for the possible management of the domain, mostly Internet service providers seeking to stake a claim, each of which were naturally unacceptable to the rest of the committee. In response to this Dr Black, as the .uk Name, stepped up with a bold proposal for a not-for-profit commercial entity to deal with the .uk domain properly. Commercial interests initially balked at this, but with widespread support Nominet UK was formed in 1996 to be the .uk Network Information Centre, a role which it continues to this day.
The general form of the rules (i.e. which domains can be registered and whether to allow second level domains) was set by the Naming Committee. Nominet has not made major changes to the rules, although it has introduced a new second level domain .me.uk for individuals.
It is prohibited until summer 2014 to register a domain name directly under .uk (such as internet.uk) and a third-level domain must be used (such as internet.co.uk).
However, some domains delegated before the creation of Nominet UK remain. Examples include mod.uk (Ministry of Defence), parliament.uk (Parliament), bl.uk and british-library.uk (the British Library), nls.uk (the National Library of Scotland), nhs.uk (The National Health Service), and jet.uk (UKAEA as operator of the Joint European Torus experimental fusion tokamak). No new 'normal' registrations at the second level are accepted although there is a system for allocating new second level domains to expand the capacity of the system. Such allocations are rarely made. Currently the rights to the .uk domain name are owned by Nominet UK. It is possible to directly register a domain name with Nominet UK, but it is faster and cheaper to do it via a Nominet registrar.
- .ac.uk - academic (tertiary education, further education colleges and research establishments) and learned societies
- .co.uk - general use (usually commercial)
- .gov.uk - government (central and local)
- .judiciary.uk - courts (to be introduced in the near future)
- .ltd.uk - limited companies
- .me.uk - general use (usually personal)
- .mod.uk - Ministry of Defence and HM Forces public sites
- .net.uk - ISPs and network companies (unlike .net, use is restricted to these users)
- .nhs.uk - National Health Service institutions
- .nic.uk - network use only (Nominet UK)
- .org.uk - general use (usually for non-profit organisations)
- .parliament.uk - parliamentary use (only for the UK Parliament and the Scottish Parliament)
- .plc.uk - public limited companies
- .police.uk - police forces
- .sch.uk - Local Education Authorities, schools, primary and secondary education, community education
- .bl.uk and .british-library.uk - British Library
- .jet.uk - Joint European Torus
- .nls.uk - National Library of Scotland; it also held another domain .national-library-scotland.uk, which has now been deleted.
Inactive second-level domains
- .icnet.uk - Cancer Research UK - now deleted.
- .govt.uk - former government domain, now deleted and replaced by .gov.uk
- .orgn.uk - former non-profit organizations domain, now deleted and replaced by .org.uk
- .lea.uk - local education authorities; since fallen out of use.
- .mil.uk - the Ministry of Defence have always used mod.uk for their external domain, but use mil.uk on their private network. mil.uk exists only as a CNAME (alias) for mod.uk in the .uk zone file. The url http://mil.uk is accessible as CNAME of http://mod.uk
- .nel.uk - National Engineering Laboratory (now TÜV NEL) - now deleted.
.co.uk, .ltd.uk, .me.uk, .net.uk, .nic.uk, .org.uk, .plc.uk and .sch.uk are managed by Nominet UK and except for .nic.uk are available for registration by the public (though they all carry various degrees of restrictions). The other second-level domains are managed by various government agencies, and generally more strongly controlled.
Rejected second-level domains
- .soc.uk - proposed for Social and Society use.
- .cym.uk - A domain for Wales; it did not have support of the Welsh Internet community, with a .cym domain being proposed, though later rejected, with either .cymru or .wales proposed Bilingual Welsh & English Customer Support Service for dotCymru and dotWales gTLDs.
- .scot.uk - A domain for Scotland; it did not have the support of the Scottish Internet community, with .sco domain being proposed.
Allocation of domain names
Allocations are on a strict first-come, first-served basis to qualified applicants. There are no territorial restrictions: applicants need not have any connection to the UK other than those outlined below for .ltd.uk and other restricted domains.
.co.uk is by far the most used of the domains, followed by .org.uk then .me.uk. .plc.uk and .ltd.uk are only rarely used. The number of new registrations for each of the different .uk domains on a month by month basis can be seen on the Nominet website (www.nominet.org.uk/intelligence/statistics/registration/)
The intended restriction of .co.uk to companies is purely nominal; in practice it is open to any and all applicants. Likewise, whilst .org.uk is for organizations, there are no restrictions on registering domains. While .me.uk originally had no restrictions on registrants it has since been tightened up to require registrants to be natural persons (i.e. not companies, etc.).
However, registrants in .ltd.uk must be, and remain, private limited companies incorporated under the UK Companies Acts. In addition, names can only be registered if they correspond (in accordance with the algorithm in the rules of registration) with the exact company name, as recorded at the companies registry at Companies House. The same conditions apply for .plc.uk, but for public limited companies. Neither of these domains is widely used.
.net.uk is more open, but the Nominet regulations still mean that a registrant must be an ISP, or a similar body, and that the domain is not used for providing services to end-users. .nic.uk, however, is limited solely to domains operated by Nominet.
.ac.uk domains are intended for the use of higher education institutions (beyond compulsory education age), and are also used by some academic support bodies such as the Universities and Colleges Admissions Service (www.ucas.ac.uk), public research establishments, and learned societies such as the Royal Society (royalsoc.ac.uk). Primary and secondary education uses .sch.uk.
Unusually, .sch.uk domains are allocated at the fourth level, with the third level being taken up by the name of the local authority (LA, previously LEA or Local Education Authority) e.g. schoolname.leaname.sch.uk. For example, The Campion School in Hornchurch has the domain name http://www.campion.havering.sch.uk/, and West Exe Technology College in Exeter has the domain name http://www.westexetc.devon.sch.uk. Previously applications were made in the normal way, but after Nominet came to an arrangement with the education authorities, one domain per school was issued automatically.
- "Nominet to introduce shorter .uk domain name registrations". 2013-11-20. Retrieved 2013-11-30.
- BBC News - Landmark 10 millionth .uk site registered with Nominet
- Domain Name Wire - .Uk domain hits 10 million milestone
- J. Postel and J. Reynolds (October 1984), Request for Comments: 920, Network Working Group
- Milton Mueller (2002), Ruling the Root: Internet Governance and the Taming of Cyberspace, Cambridge, Massachusetts: MIT Press, p. 79, ISBN 9780262632980
- "Nominet history (from archive.org)". Archived from the original on 2002-06-02. Retrieved 2009-07-15.
- BBC News - UK court systems set to adopt judiciary.uk domain names
- The registration process and a list of domain names for the .police.uk domain was released by the National Policing Improvement Agency under a Freedom of Information request on 10 March 2009.
- "Campion School Havering". Archived from the original on 1 June 2009. Retrieved 30 May 2009.