The exception to the rule
Almost every ccTLD matches its country's ISO 3166-1 code. The United Kingdom is the famous exception: its ISO code is GB, but the country has used .uk since 1985. The .gb TLD does exist in the root zone, but it's reserved and has never been opened for registrations.
The registry is Nominet, a not-for-profit based in Oxford.
co.uk, org.uk and plain .uk
For decades, British websites lived one level down: .co.uk for companies, .org.uk for organizations, .ac.uk for universities, .gov.uk for government. In June 2014 Nominet opened direct registrations, so example.uk became possible too. Both exist side by side, and .co.uk is still the ending many Britons type first.
Good for
- Businesses and organizations targeting UK customers
- Brands that want to signal they're British
Watch out for
- Many UK consumers still expect .co.uk
- .uk names are run under UK law and Nominet's policies
.uk by the numbers
.uk is the internet country code for United Kingdom. It's one of Northern Europe's ccTLDs, the two-letter domains reserved for countries and territories. The United Kingdom's ISO 3166-1 code is actually GB, but the country has used .uk since the earliest days of the DNS, and "UK" is exceptionally reserved in ISO 3166-1 so the two can coexist.
A little context on United Kingdom: the capital is London, the main language is English, the currency is the British pound (GBP) and the international dialing code is +44.
Next door on the map, you'll find .ie for Ireland.
IANA lists Nominet UK as the manager of .uk, with an address in United Kingdom of Great Britain and Northern Ireland. The registry's website is http://www.nic.uk. ccTLD managers set their own policies — who can register, which second-level names exist, pricing to registrars — so those rules differ from country to country.
Under the hood, the root zone points to 8 name servers for .uk, every one of them reachable over IPv6. The delegation is DNSSEC-signed, so resolvers can verify that answers for .uk haven't been tampered with on the way. Registration data is published over RDAP.
United Kingdom also has another country-code domain in the root zone: .gb.
Same registry, other endings
2 other TLDs share this operator.
.uk vs other endings
.uk FAQ
Why is the UK .uk and not .gb?
.uk was in use from the earliest days of the DNS, before the ccTLD list settled on ISO 3166-1 codes. "UK" is now exceptionally reserved in ISO 3166-1 so the two can coexist. A .gb TLD exists but has never been used for open registration.
What's the difference between .uk and .co.uk?
.co.uk is a second-level space under .uk that has been used for businesses for decades. Since June 2014 you can also register directly under .uk (example.uk).
What country is .uk?
.uk is the country-code top-level domain for United Kingdom, in Northern Europe.
What is United Kingdom's domain extension?
United Kingdom's website extension is .uk, its country-code top-level domain. It also has .gb in other scripts. "UK" is its ISO 3166-1 alpha-2 code.
Who owns the .uk domain?
IANA lists Nominet UK as the manager of .uk: it runs the registry and sets the rules for United Kingdom's ccTLD. Individual .uk names belong to whoever registers them.
Can I register a .uk domain from the US?
It depends on Nominet UK's policy. Some ccTLDs are open to anyone in the world, while others require a local address, company or trademark. Check the registry (http://www.nic.uk) or an accredited registrar before you buy.
Is .uk DNSSEC-signed?
Yes. The root zone has a DS record for .uk, so DNSSEC validation works all the way down from the root.
How do I look up who owns a .uk domain?
Query the registry's registration data service: RDAP lookups go to https://rdap.nominet.uk/uk/. Many registrants use privacy services, so personal details may be hidden.
Sources
Data from IANA root zone version 2026102000. Last changed October 21, 2026. Spotted something wrong? Tell us.
