| Controlled Space Limited | Leeds | 2002 |
| Controllers Community Ltd | London | 2025 |
| Convenient PT Ltd | Dunstable | 2021 |
| Convergence@Lurgancastle Ltd | Craigavon | 2025 |
| Conversation Shed Limited | Wakefield | 2022 |
| Convivium Event Services Ltd | Gainsborough | 2024 |
| Convrts Ltd | Liverpool | 2017 |
| Conway Bros. (Vision) Limited | Cookstown | 1986 |
| Conway Lighting Limited | Isleworth | 2016 |
| Conway LTC | London | 2005 |
| Conway Yacht Club, Limited | Deganwy | 1962 |
| Conwy Borough Football Club C.I.C. | Conwy | 2012 |
| Conwy Creative Ltd | Conwy | 2021 |
| Conwy Fishing Ltd | Llandudno Junction | 2018 |
| Conwy Motor-Cycle Club Limited | Llandudno | 2003 |
| Conwy Pirates CIC | Colwyn Bay | 2024 |
| Conyak Productions Limited | Bromsgrove | 2022 |
| Conynger Limited | London | 2014 |
| Cook and Associates Limited | Bromsgrove | 1999 |
| Cook Brewster Smith Limited | Petersfield | 1997 |
| Cook PYE Productions Ltd | London | 2024 |
| Cooke and Deaton Table Tennis Ltd | Sheffield | 2024 |
| Cooke Industries Limited | London | 2005 |
| Cookham Cocktail Club Limited | Marlow | 2021 |
| Cookham Riding School Ltd. | Maidenhead | 2007 |
| Cookhill Cricket Club Limited | Pershore | 1997 |
| Cookiapple Ltd | Newcastle Upon Tyne | 2025 |
| Cookie Cake Studios Limited | London | 2021 |
| Cookie LA Scribblez Limited | London | 2026 |
| Cookie Racing Limited | Workington | 2015 |
| Cookies Competitions Ltd | Middlesbrough | 2025 |
| Cookies Island Limited | London | 2010 |
| Cooking IT Corporate Events Ltd. | Bristol | 2024 |
| Cookney Public Hall | Stonehaven | 2009 |
| Cookridge Hall Golf Club (Leeds) Limited | Leeds | 2021 |
| Cookridge Hall Golf Club Limited | Leeds | 2004 |
| Cookridge Hall Health & Fitness Limited | Darlington | 2011 |
| Cooks Competitions Ltd | Middlesbrough | 2025 |
| Cookson Mcdonald Ltd | Chichester | 2005 |
| Cookstown & District Motor Cycle Club (Road Racing) Limited | Co Tyrone | 2002 |
| Cookstown and District Motor Cycle Club | | 1976 |
| Cookstown Gymnastics Ltd | Cookstown | 2022 |
| Cookstown Motor Club Limited | Dungannon | 1971 |
| Cool Capital Partners Ltd | London | 2026 |
| Cool Castles Ltd | Strabane | 2019 |
| Cool Girl Clubhouse Ltd | Tonypandy | 2025 |
| Cool Girl Music Ltd | Erlestoke | 2023 |
| Cool Hand Media Group Limited | London | 2015 |
| Cool Hand Promotions Limited | Brough | 2013 |
| Cool Hooves Polo Limited | Warfield | 2003 |
| Cool IT Art Limited | London | 2013 |
| Cool Katz Limited | London | 2016 |
| Cool Music Group Ltd | Fleet | 2026 |
| Cool Parties & MPL Events Ltd | Rossendale | 2025 |
| Cool Parties Ltd | London | 2018 |
| Cool Play (Sturminster Newton) Limited | Cardiff | 2004 |
| Cool Ridings Ltd | London | 2023 |
| Cool Running Motorsports Limited | Old Hatfield | 2016 |
| Cool Surface Limited | Swindon | 2008 |
| Cool Swim Ltd | Burntwood | 2023 |
| Cool Under Fire Ltd | Romford | 2013 |
| Cool Vibrations Ltd. | London | 2013 |
| Cool Waves Swim School Ltd | Grimsby | 2021 |
| Coolconnections Limited | Hailsham | 2010 |
| Coolcorp Limited | Southend On Sea | 1997 |
| Cooldog Studios Limited | Ely | 2022 |
| Cooley Castles Ltd | Co Tyrone | 2006 |
| Coolflight Limited | London | 2004 |
| Coolhurst Lawn Tennis and Squash Rackets Club | Kingston Upon Thames | 2010 |
| Coolite Fitness Ltd | London | 2023 |
| Coolstill Limited | London | 2015 |
| Coolsummer Songs Limited | Hove | 2000 |
| Coombe Hill Holdings (1946) Limited | Kingston On Thames | 1946 |
| Coombe Wood Golf Club Limited | Surrey | 1961 |
| Coombe Wood Lawn Tennis Club Limited | Surrey | 1935 |
| Coonart Ltd | Borough | 2022 |
| Coool Communications Limited | | 1995 |
| Coopah Limited | London | 2020 |
| Cooper & Hopkins Ltd | Sevenoaks | 2019 |
| Cooper Biscayne Limited | Birmingham | 2026 |
| Cooper Darwin Bloodstock Ltd | Newmarket | 2018 |
| Cooper Design Ltd | Glastonbury | 2025 |
| Cooper Entertainment Services Ltd | Walsall | 2019 |
| Cooper Studio Ltd | Great Missenden | 2018 |
| Cooper Stunts Ltd | Hitchin | 2015 |
| Cooper's Hill Recreational Trust Limited | Wokingham | 1972 |
| Coopers Amusements Limited | Newport | 2024 |
| Coopers Coborn Allweather Pitch Ltd. | Essex | 1993 |
| Coopers Country Limited | Ipswich | 2003 |
| Coopers Media Limited | Liverpool | 2025 |
| Coopers Troopers Fitness Ltd | Solihull | 2021 |
| Coops Soccer School Limited | Huntingdon | 2025 |
| Coorie Doon Party Ltd | Glasgow | 2023 |
| Copa Summit Limited | Leeds | 2014 |
| Copcut Golf Centre Limited | Droitwich | 2005 |
| Copdock and Old Ipswichian Cricket Club Limited | Ipswich | 2020 |
| Copdock Motorcycle Events Ltd | Ipswich | 2014 |
| Cope & Cabrera Limited | Ware | 2015 |
| Cope Design Associates Limited | Maidenhead | 1974 |
| Copeland Zamora Enterprises Ltd | Bury St Edmunds | 2016 |