| Clip and Climb Fulham Limited | London | 2013 |
| Clip Craft Emporium Limited | Kington | 2024 |
| Clip Media Ltd | Manchester | 2025 |
| Clip N Climb Bristol Limited | Bristol | 2015 |
| Clip N Climb Dundonald Ltd | Belfast | 2012 |
| Clip N Climb High Wycombe (Eden) Ltd | Whitstable | 2024 |
| Clip N Climb Leeds Limited | Leeds | 2019 |
| Clip N Climb Preston Limited | Preston | 2016 |
| Clip N Climb Thanet Ltd | Whitstable | 2020 |
| Clip'N Climb Plymouth Ltd | Kelbrook | 2015 |
| Clipnclimb (Ilkley) Ltd | Ilkley | 2015 |
| Clippd Limited | London | 2016 |
| Clippits Motorsport Limited | Leicester | 2021 |
| Clique (H) Ltd | Leeds | 2018 |
| Clique College Ltd | Chatham | 2021 |
| Clique Events Ltd | London | 2025 |
| Clis Secret 10 Ltd | Carrickfergus | 2024 |
| Clitheroe Angling Association Limited(The) | Clitheroe | 1956 |
| Clitheroe Canoe Club Limited | Accrington | 2025 |
| Clitheroe Cricket Club CIC | Clitheroe | 2023 |
| Clitheroe Cricket, Bowling and Tennis Club Limited | Lancs | 1974 |
| Clitheroe Football Club Limited | Clitheroe | 2012 |
| Clitheroe Golf Club Limited | Near Clitheroe | 1932 |
| Clitheroe Leisure Ltd | Clitheroe | 2018 |
| Clitheroe Rugby Union Football Club Limited | Blackburn | 2011 |
| Clive Bradley Limited | Middlesex | 2007 |
| Clive Conway Productions Limited | Adderbury | 2003 |
| Clive COX Racing Limited | Hungerford | 2006 |
| Clive John Productions Limited | Malvern | 2020 |
| Clive Motor Cycle Club Limited | Welshpool | 1994 |
| Clive Sefton Limited | Brighton | 2012 |
| Clix Records Ltd | Burton-On-Trent | 2005 |
| Clixby Active Pro Sports Ltd | Brigg | 2017 |
| Cljm Limited | Leicester | 2018 |
| CLL & Co Promotions Limited | Northampton | 2010 |
| Cllr Ltd | London | 2019 |
| CLM Productions Limited | London | 2015 |
| Clmpro Entertainment Ltd | Bristol | 2021 |
| Cloak & Dagger Distribution Limited | Enfield | 2014 |
| Cloak and Dagger Studios Ltd | Halkirk | 2022 |
| Cloak and Daguerre Ltd | Chippenham | 2012 |
| Cloaked Events Ltd | London | 2025 |
| Clober Golf Course Limited | Glasgow | 1963 |
| Clock & Chair Limited | London | 2025 |
| Clock Cricket CIC | Welwyn Garden City | 2022 |
| Clock Tower Films Limited | Spilsby | 2018 |
| Clocktime | Edinburgh | 2024 |
| Clockwork Artists Ltd | Birmingham | 2023 |
| Clockwork Audio Ltd | Milton | 2025 |
| Clockwork Automation Ltd | Manchester | 2012 |
| Clockwork Digital Limited | Middlesex | 2008 |
| Clockwork Entertainments Limited | London | 2010 |
| Clockwork INK Tattoo Studio Ltd | Canterbury | 2018 |
| Clockwork Monkey Studios Limited | Baschurch | 2011 |
| Clockwork Production Ltd | Lytham St. Annes | 2004 |
| Clockwork Soldier Limited | London | 2010 |
| Clogher Valley Community Centre | | 2006 |
| Clonaneese Development Group | Dungannon | 2018 |
| Clonoe Cyclone Darts Ltd | Brierley Hill | 2026 |
| Clonoe Padel Ltd | Magherafelt | 2026 |
| Clonter Farm Music Trust | Congleton | 2000 |
| Clontyseer Racing Ltd | Birmingham | 2024 |
| Cloo Entertainment Ltd | Bristol | 2025 |
| Clooneavin Bloodstock Limited | Newry | 2024 |
| Clooney FC Community Sports Limited | Londonderry | 2013 |
| Close Cosmos Ltd | London | 2026 |
| Close Group Ltd | Lymington | 2024 |
| Close House Golf Club Limited | Newcastle Upon Tyne | 2007 |
| Close House Limited | London | 2016 |
| Close Order Ltd | Nottingham | 2024 |
| Close Racing Limited | Ashington | 2017 |
| CLOSE2NATURE Film Ltd | Epsom | 2023 |
| Closed SET Limited | Borough | 2004 |
| Closer Each Day Company | Bristol | 2016 |
| Closet Gnomes Ltd | Bath | 2008 |
| Closetq.Ai Limited | Swindon | 2026 |
| Cloud 9 Complex Limited | Halifax | 2023 |
| Cloud 9 Creative Production Ltd. | Rayleigh | 2013 |
| Cloud 9 Divine Ltd | London | 2021 |
| Cloud 9 Hang Gliding & Paragliding Limited | Redruth | 2010 |
| Cloud 9 Leisure Limited | Brighton | 2017 |
| Cloud 9 Reformer Pilates Ltd | Atherstone | 2025 |
| Cloud 9 Scooter Club Birkenhead C.I.C. | Irby | 2025 |
| Cloud 9 Sports Limited | Chelmsford | 2016 |
| Cloud 9 Sports Management Ltd | London | 2023 |
| Cloud 9 Tatu Ltd. | Bristol | 2019 |
| Cloud 9 Yoga Ltd | Clydebank | 2016 |
| Cloud Aerial Arts Limited | Middlewich | 2017 |
| Cloud Competitions (Cumbria) Ltd | Whitehaven | 2023 |
| Cloud Copy Limited | Banbury | 2020 |
| Cloud Cuckoo Land Theatre Ltd | Birmingham | 2020 |
| Cloud Formations Group Limited | Pontyclun | 2020 |
| Cloud Hammer Limited | Moira | 2011 |
| Cloud Houses Limited | Newcastle Upon Tyne | 2009 |
| Cloud Nine Competitions Pltd Limited | Newry | 2020 |
| Cloud Nine Decor Limited | Sheffield | 2018 |
| Cloud Nine Design & Print Limited | Pickering | 2010 |
| Cloud Nine Pilates Ltd | Sawbridgeworth | 2023 |
| Cloud Nine Playtime Limited | Eastbourne | 2025 |
| Cloud Nine Theatre Productions Company | North Shields | 2000 |