Published: 19.06.2026
For decades, .co.uk was the standard address of a commercial site in the United Kingdom. It is still recognised by British visitors as a sign of a local company, and it is one of the largest country-code zones in the world.
Check if a .co.uk domain is available .co.uk Check
A short history
The .uk domain was set up in the mid-1980s, among the first country-code domains, and the "co" second-level zone was created for commercial organisations, in the same way that "ac" was used for academic ones. For almost thirty years, a British company would register a name in .co.uk, and it became a mark of a local business. In 2014 the registry also opened direct registrations in .uk, and holders of the older names were given a period of priority to claim the shorter version.
Who runs it
The zone is managed by Nominet, a not-for-profit organisation that operates the registry and sets the rules. Names are sold by registrars, who must follow the registry policies. Nominet also runs a dispute resolution service for cases such as cybersquatting.
Rules in practice
- Technical rules: names can be up to 63 characters with letters, digits and hyphens before the .co.uk part.
- Periods: registrations are usually from one to ten years.
- Contact data: the registry requires accurate details for the registrant and may check them. Read the current policy about the contact address before you register, because requirements have changed over time.
- Security: DNSSEC is supported, and the registry offers tools to protect against fraud.
- Related names: .co.uk sits next to .org.uk, .me.uk, .ltd.uk and others, each for a different type of owner.
Who uses .co.uk
- British companies of all sizes, from sole traders to large retailers.
- Foreign businesses that sell to customers in the UK.
- Online shops that want their address to look familiar to British shoppers.
- Local service providers: plumbers, accountants, estate agents, restaurants.
Strengths
The ending is very familiar and trusted by UK users. It tells search engines and visitors that the site is oriented to Britain, which helps local search. The registry is stable, and the zone is well protected against abuse.
Weaknesses
- It is longer than .com or .uk, so it is a bit harder to type on a phone.
- For an international audience a .com may be better.
- The best short names are taken, so you may need a descriptive combination.
Tips before you register
- Decide if you also want the shorter .uk version of the name and check whether it is reserved for the .co.uk owner.
- Use the same name in .com if you plan to sell outside the UK.
- Keep the contact details exactly as in your company records.
- Set up the website with a server in Europe so that British visitors get fast pages.
- Enable auto-renewal and watch for the renewal notices.
Frequently asked questions
Do I need to be in the UK? Many registrars allow registrations from abroad, but the registry has rules about contact details, so check the policy.
Is .co.uk better than .uk? They are equal in function. .uk is shorter, .co.uk is better known.
Can I transfer the domain? Yes. Change the registrar tag with the help of your current registrar.
