| Clever Girl Enterprises Limited | London | 2025 |
| Clever Jackie Pictures Ltd | Bromsgrove | 2019 |
| Clever Make Funny Productions Ltd | London | 2017 |
| Clever Media Solutions Limited | London | 2009 |
| Clevercat Productions Limited | | 2006 |
| Clevergreen Group Ltd | Hurstpierpoint | 2018 |
| Cleverlx Limited | London | 2016 |
| CLF High Street Kensington Limited | London | 2021 |
| CLF Ventures Ltd | Manchester | 2018 |
| CLH Entertainments Ltd | Keighley | 2026 |
| Cli's Secret Ltd | Carrickfergus | 2023 |
| Cli's Secret Online Ltd | Carrickfergus | 2024 |
| Clic Sargent Lottery Limited | Bristol | 2017 |
| Click Bristol Ltd | Bristol | 2025 |
| Clicket Competitions Ltd | London | 2025 |
| Clickuk Limited | London | 2012 |
| Client Side Ltd | Gainsborough | 2022 |
| Cliff Adams Management Limited | Loughton | 1960 |
| Cliff Stud Limited | York | 2016 |
| Cliffcoll Limited | Hay On Wye | 2010 |
| Cliffe Bowls Club Community Interest Company | Rochester | 2025 |
| Cliffe Collective Ltd | Bristol | 2025 |
| Cliffe Freelancing Limited | Bridport | 2025 |
| Cliffe Jones Ltd. | Glasgow | 2002 |
| Cliffeco Limited | Whitchurch | 1989 |
| Cliffhanger Experiences Ltd | Stockport | 2023 |
| Cliffhanger London Ltd | Loughton | 2026 |
| Cliffhanger Musical Productions Ltd | London | 2018 |
| Clifford LEE Limited | Liverpool | 2025 |
| Cliffords Leisure Limited | Chelmsford | 1999 |
| Clifftop Projects CIC | Dumbarton | 2020 |
| Clifton Academy of Dance Drama & Music Limited | Lytham St. Annes | 2006 |
| Clifton Bingo Club Limited | York | 1936 |
| Clifton Charterhouse Securities Limited | Horsham | 1974 |
| Clifton College Services Limited | Bristol | 1993 |
| Clifton Edition Ltd | Bristol | 2023 |
| Clifton Festival Ltd | Bury | 2025 |
| Clifton Field Sports Limited | Aberdeen | 2014 |
| Clifton Fitness Limited | Bristol | 2023 |
| Clifton House Centre Limited | Belfast | 2010 |
| Clifton Interiors Limited | London | 1986 |
| Clifton Lawn Tennis Club Limited | Bristol | 1970 |
| Clifton PT Limited | Bristol | 2017 |
| Clifton Railway Ltd | Bristol | 2018 |
| Clifton Softball League | Bristol | 2018 |
| Clifton Tennis Academy Limited | Bristol | 2025 |
| Clifton Third Ltd | Potters Bar | 2022 |
| Cliftonshire Limited | Barnet | 1983 |
| Cliftonville & Coatdyke Community Group | Coatbridge | 2019 |
| Cliftonville Bowling Club, Limited | | 1919 |
| Cliftonville Football and Athletic Club Limited | Cliftonville Street | 1912 |
| Cliftonville Golf Club, Limited | Belfast | 1922 |
| Climarts ED CIC | London | 2022 |
| Climate Fiction Prize Ltd | New Malden | 2025 |
| Climate Live | Frome | 2020 |
| Climavore CIC | Portree | 2019 |
| Climb - MAX Limited | Lytham St. Annes | 2013 |
| Climb Competitions Ltd | Norwich | 2025 |
| Climb Hard BE Kind Mountaineering Limited | Leeds | 2025 |
| Climb Higher Limited | King'S Lynn | 2011 |
| Climb Hire Limited | Sheffield | 2013 |
| Climb Hitchin CIC | Chalfont St. Giles | 2023 |
| Climb Newcastle Limited | Newcastle Upon Tyne | 2007 |
| Climb North East Limited | Blaydon-On-Tyne | 2016 |
| Climb Snowdonia C.I.C. | Caernafon | 2016 |
| Climb South West Ltd | Budleigh Salterton | 2018 |
| Climb the Beanstalk Ltd | London | 2026 |
| Climb Torridon Ltd | Gairloch | 2022 |
| Climb Worcester Ltd | Worcester | 2013 |
| Climbahub Limited | Newcastle Upon Tyne | 2024 |
| Climbing Club Ltd | Portsmouth | 2025 |
| Climbing Collective Ltd | Llantwit Major | 2020 |
| Climbing Creative Limited | London | 2016 |
| Climbing High C.I.C. | Birmingham | 2012 |
| Climbing HUT Holdings Limited | Ellesmere Port | 2020 |
| Climbing HUT Shrewsbury Limited | Ellesmere Port | 2021 |
| Climbing HUT Three Limited | Ellesmere Port | 2022 |
| Climbing Life Ltd | Wareham | 2017 |
| Climbing Matrix Ltd | Swanley | 2025 |
| Climbing Performance LAB Ltd | London | 2022 |
| Climbing SC Ltd | Watford | 2026 |
| Climbing Services Ltd | Bolton | 2018 |
| Climbing Wall Services Ltd | Menai Bridge | 2011 |
| Climbtop Limited | Epsom | 2002 |
| Clinic GB Limited | London | 2007 |
| Clinic Talent Limited | London | 2015 |
| Clinical Productions Ltd | High Wycombe | 1998 |
| Clinivi Wellness CIC | Darlington | 2026 |
| CLINT419 Ltd | London | 2023 |
| Clinton Woods Enterprises Ltd | Sheffield | 2010 |
| CLINTON14 Limited | Doncaster | 2015 |
| Clints Fest Ltd | Salford | 2025 |
| Clio Hope Films Ltd | Whitstable | 2015 |
| Clio Peppiatt Ltd | Leicester | 2018 |
| Clio's Company | | 2004 |
| Clioti Limited | London | 1999 |
| Clip 'N Climb Crawley Limited | Redhill | 2006 |
| Clip 'N Climb Ipswich Limited | Stowmarket | 2018 |
| Clip 'N Climb Nation Ltd | Bury St Edmunds | 2024 |
| Clip 'N Climb North West Limited | Burnley | 2026 |