What’s the Difference Between co.uk and .uk?

17th May, 2017 by

When the World Wide Web debuted in 1991, its developers had anticipated limited demand for website domains. Alongside the ubiquitous .com and .org suffixes, country code top level domains (or ccTLDs) were released for nations and principalities from the Ascension Islands to Zimbabwe. Every nation had a ccTLD to identify domestic businesses, enabling citizens to establish their origins through their web addresses and email accounts.

Nobody could have predicted the meteoric growth of internet traffic, or the subsequent boom in website registrations. Following a protracted free-for-all, the Internet Corporation for Assigned Names and Numbers (ICANN) was established in 1998 to regulate the supply of domain names. Creating new top level domains has been a key focus ever since  then, reducing demand for the limited number of global and country code TLDs initially released.

Today there are over 1,500 TLDs to choose from. The co.uk address is one of fifteen third-level domains allocated to the United Kingdom, alongside ac.uk (for academic institutions) and org.uk (for non-profit organisations). However, the company-oriented suffix rapidly became our dominant ccTLD. Its widespread adoption eventually inspired the launch of the .uk namespace in 2014, to alleviate growing demand for co.uk sites.

A handful of public websites were able to use the second level .uk TLD prior to its public release, such as parliament.uk and nhs.uk. Its universal release nonetheless represented a fairly significant change in the UK’s domain name system.


However, there’s more than one difference between co.uk and .uk addresses, as outlined below:



One clear difference between co.uk and .uk domains involves the latter’s superior availability, since it’s only been with us for a fraction of the former’s 26-year lifespan. New businesses often experience difficulty finding a suitable co.uk domain to register, unless their company name is highly unusual. There are unlikely to be availability issues with .uk suffixes, unless your firm has a generic title like Astra or Acme.


Although search engine algorithms don’t discriminate against newer TLDs, they do factor in traffic volumes. People are naturally wary about entering an unusual address into their browser, particularly a ccTLD they’re not familiar with. A key difference between co.uk and .uk domains involves a greater willingness among consumers to visit the former. Since lower traffic volumes reduce a site’s overall SEO performance, that’s worth considering.


Because we’ve had a quarter of a century to familiarise ourselves with co.uk addresses, they trip off the tongue with no ambiguity. A .uk suffix, on the other hand, could cause confusion. People might enter the co. part out of habit, leading them onto a completely different website. It’s always important to choose a website address that can easily be dictated down the phone, yet the difference between co.uk and .uk isn’t always evident straight away.

Industry differentiation

At the moment, a private company can differentiate itself from a charitable organisation or an academic establishment by using a third level domain. There’s no scope to do this with a simple .uk suffix. That’s fine for brands with highly unusual titles, but potentially troublesome if different institutions with the same name ended up competing for the same domain. There is greater potential for confusion and accidental site visits with a .uk suffix.

International appeal

Many overseas countries avoid third level domains like our .org.uk or .sch.uk, preferring two-letter ccTLDs. Choosing a second level .uk web address brings British organisations and companies into line with foreign audiences. India has gradually transitioned from co.in to the simpler .in, and industry observers predict the UK might follow suit once the .uk suffix is derestricted in 2019.


Given the potential confusion between co.uk and .uk domains outlined above, why not acquire both? Anyone who’s already registered a co.uk site has until 2019 to claim the .uk counterpart before it goes on public sale. Owning both will ensure people are safely delivered to the canonical URL identified as a main destination page with a redirect or a homepage link. UK2 sells .uk domains from just £1 per year, which is a tiny price to pay for full domestic control over your chosen domain name…

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Ready to register your .uk or co.uk domain name with UK2?