TR

.co.uk domain: registry, rules and WHOIS

UK businesses and commercial sites

Facts

Type
Second-level zone under .uk
Registry operator
Nominet
Country or territory
United Kingdom
RDAP
Yes (rdap.nominet.uk)
Registration
Open to anyone
Typical use
UK businesses and commercial sites

RDAP availability is taken from the IANA RDAP bootstrap file published on 2026-09-16; WHOIS server and delegation year from the IANA root zone database. Registry policies change: check the registry's own policy before relying on an eligibility rule.

What is .co.uk?

.co.uk is the commercial second-level zone under .uk and by far the best-known British extension. It is not a top-level domain of its own: it is a zone that Nominet operates inside .uk, and it appears on the Public Suffix List, so browsers and tools treat example.co.uk as a registrable domain.

Who can register it

Open to anyone, in the UK or abroad, first come, first served. The same Nominet data-validation rules apply as for .uk.

WHOIS, RDAP and privacy

An RDAP service for .uk (rdap.nominet.uk) is published in the IANA RDAP bootstrap file. OrbitProbe reads registration data from it first, as structured JSON: registrar, creation and expiry dates, EPP status codes and nameservers. For ccTLDs, what is published is decided by the registry and local law rather than by ICANN, so output differs from one extension to the next. Most registries do not show the personal data of individuals in public output. OrbitProbe only ever shows the organisation name and country.

Look up a .co.uk domain

FAQ

Who can register a .co.uk domain?

Open to anyone, in the UK or abroad, first come, first served. The same Nominet data-validation rules apply as for .uk.

How do I run a WHOIS lookup for a .co.uk domain?

Type the name, in the form example.co.uk, into the form on this page. OrbitProbe first queries the RDAP service of the .uk registry (rdap.nominet.uk). The result shows where the data came from and when it was observed.

Does .co.uk support RDAP?

Yes. The IANA RDAP bootstrap file dated 2026-09-16 publishes rdap.nominet.uk for .uk. The IANA record does not list a separate WHOIS server.

Is .co.uk a top-level domain?

No. The top-level domain is .uk; .co.uk is a second-level zone the registry operates beneath it. Because it is on the Public Suffix List, tools and browsers treat example.co.uk as the registrable domain. WHOIS and RDAP data come from the .uk registry.