BellaOnline has a large American readership, but writers here know we have a worldwide audience. Sweepstakers in the UK have many resources to turn to on the internet. Here are several based in the UK and one in the US with a section for UK visitors. BellaOnline requires that I limit clickable links in articles, so I've placed the URLs next to the site names.
My UK Competitions (http://www.myukcompetitions.co.uk/): There are tons of great prizes listed at this site. All of the competitions are free to enter but may require liking on Facebook, completing a survey or signing up for a newsletter. My UK Competitions has their own newsletter you can sign up for to keep updated on current contests.
UK Competitions (http://www.ukcompetitions.com/): This is another free site with listings updated daily. Win everything from cash prizes, books and beauty items to vacations, automobilies and computer gear. You need to give your name and email address to join. Members have the added perk of receiving info about new competitions two weeks before nonmembers.
UK Prize (http://www.ukprize.co.uk/): Another site that's free to join for UK residents over the age of 18. According to the website, with your permission they may contact you with advertisements once you sign up. They have a Facebook, Twitter and Google+ presence. In fact, most of these sites I've listed have a social networking presence. UK Prize has competition listing for cash, car, entertainment, electronic prizes and many more.
UK Wins (http://www.ukwins.co.uk/): This site has listings including a section for UK bingo websites, Twitter competitions, and links to many sweepstakes. There is also a discussion forum for members.
Popular American, Canadian and other sweepstakes may have international entries so don't discount them out of hand. Just check the official rules for eligible locations.
Sweepstakes Advantage has a huge directory of free sweepstakes and contests mainly for Americans, but there are sections at the site devoted to UK and Canadian opportunities too. Visit the UK section of the site here. Good luck to all my UK readers.