UKTV, a company that operates a number of basic cable television stations in the United Kingdom, has changed its name to U and is currently using u.co.uk as its primary target domain.
.co.uk is the country top-level domain (ccTLD) for the United Kingdom (UK).
Its channels have been renamed to the domain names resistant U&Dave, U&W, U&DRAMA and U&YESTERDAY, and the “primary brand” U will be used for its streaming services.

u.co.uk website
The domain name u.co.uk was registered on March 23, 2011 and released that same year as part of Nominet's release of single and two-character domain names. It was claimed as a trademark by multiple parties and auctioned off for a possible four-figure sum.
The winning bidder in 2011, Ubrands, appears to have never used the domain name, and it is unclear how much U paid when the domain changed hands this time around.
The corresponding second-level domain name, u.uk, is owned by a domain name investment company and has a BIN price of £500,000 on its landing page.
It is not uncommon for websites to use a single letter as a domain name, as these domain names are extremely rare and have a high market value. Below are some examples of well-known websites that use single letter domain names:
1.q.com: owned and used by CenturyLink, an American telecommunications company.
2.x.com: Originally founded by Elon Musk as an online payment company, it has been repurchased by him and is now used as the official domain name of Twitter.
3.g.cn: Owned by Google and used to point to Google China.
4.z.com: Owned and used by Japanese Internet service provider GMO Internet.
These single letter domain names are usually owned and used by large companies or well-known brands because of their simplicity and high brand value and recognition.
Source: domainincite