| Client Sphere Ltd | Sheffield | 2022 |
| Client Support Services (UK) Limited | Loughton | 2007 |
| Clientboost Ltd | London | 2026 |
| Clientearth Trading Ltd | London | 2020 |
| Clientology Ltd | Liverpool | 2017 |
| Clientx Ltd | London | 2024 |
| Cliff & MI Ltd | Rochester | 2019 |
| Cliff Barbers Ltd | Manchester | 2022 |
| Cliff Bradley & Sons Funeral Directors Limited | Lincolnshire | 1999 |
| Cliff Bradley Memorials Limited | Gainsborough | 2024 |
| Cliff Enterprise Ltd | Leeds | 2024 |
| Cliff House Clinic Limited | Southend On Sea | 2014 |
| Cliff Kaneli Ltd | Letchworth Garden City | 2016 |
| Cliff Ltd | London | 2018 |
| Cliffe Beauty Studio Ltd | Rochester | 2025 |
| Cliffe Bonfire Limited | Lewes | 2008 |
| Cliffe Cattery Ltd | Rochester | 2015 |
| Cliffe Interiors Limited | Burton-On-Trent | 2019 |
| Clifford Court (Grange Road) Limited | Bishop'S Stortford | 2008 |
| Clifford Installations Limited | Bagshot | 2018 |
| Clifford Ward Funeral Directors Limited | Preston | 2005 |
| Clifford's Family Funeral Directors Limited | Plymouth | 2019 |
| Cliffside (Cliftonville) Management Company Ltd | Ramsgate | 2005 |
| Cliffton Group Ltd | London | 2018 |
| Clifftop Kennels Limited | Lincoln | 2014 |
| Clifton Barbers Ltd | Bristol | 2025 |
| Clifton 2022 Barber Ltd | York | 2026 |
| Clifton Antiquarian Club | Bristol | 2006 |
| Clifton Bethesda Church Limited | Bristol | 2011 |
| Clifton Cobbler Limited | Keynsham | 2009 |
| Clifton Computer Care Limited | Bristol | 2006 |
| Clifton Consultancy Ltd | Swansea | 2023 |
| Clifton Cosmetics Ltd | Bristol | 2019 |
| Clifton Diocese | Bristol | 2016 |
| Clifton Dog Grooming Ltd | Bristol | 2019 |
| Clifton Equity Ltd | Rowley Regis | 2024 |
| Clifton Estates (Pubs) Ltd | Wallington | 2014 |
| Clifton Family Fibre Ltd | Romney Marsh | 2025 |
| Clifton Gardens Freehold Limited | London | 2008 |
| Clifton Hairdressing Limited | | 2002 |
| Clifton House (Eastbourne) Residents Association Limited | Polegate | 1976 |
| Clifton Instrumentation Ltd | Warrington | 2002 |
| Clifton Landscapes (North West) Limited | Runcorn | 2010 |
| Clifton Massage Limited | Bristol | 2012 |
| Clifton Nails & Spa Ltd | Bristol | 2024 |
| Clifton Neighbours Limited | Bristol | 2022 |
| Clifton Road Hair & Beauty Limited | Middlesex | 2004 |
| Clifton Road Residents(Wimbledon)Limited | London | 1972 |
| Clifton Skin & Beauty Ltd | Chepstow | 2006 |
| Clifton Therapy Limited | Bristol | 2018 |
| CLIK2 Limited | Stockport | 2012 |
| Clikfix Ltd | Saffron Walden | 2010 |
| Clima Veritas Ltd | London | 2024 |
| Climaflow Technologies Ltd | Upminster | 2025 |
| Climate Action Durham Community Interest Company | Durham | 2021 |
| Climate Action Network UK Limited | London | 2023 |
| Climate Action Newtown CIC | Newtown | 2021 |
| Climate Catalyst Europe | Sutton Courtenay | 2025 |
| Climate Coach Ltd | London | 2023 |
| Climate Contingency Hub Ltd | London | 2025 |
| Climate Cooling Services Limited | Newcastle Upon Tyne | 2003 |
| Climate Craic CIC | Bangor | 2022 |
| Climate Fintech Limited | Shepton Mallet | 2019 |
| Climate Jobs UK Ltd | London | 2025 |
| Climate Markets & Investment Association Limited | London | 2006 |
| Climate MIX Limited | London | 2023 |
| Climate Policy and Strategy Associates Ltd | London | 2021 |
| Climate Risk Services Ltd | Bristol | 2021 |
| Climate Services Limited | Glasgow | 2025 |
| CLIMATE1 Advisory Ltd | London | 2024 |
| Climateaction.Tech CIC | Minehead | 2023 |
| Climax Management Limited | London | 2016 |
| Climax Music Holdings Limited | London | 2018 |
| Climax Records Limited | London | 2019 |
| Climb 365 Limited | Kendal | 2013 |
| Climb and Balance Ltd | Chester | 2022 |
| Climb Dartmoor Ltd | Plymouth | 2022 |
| Climb in Flow Limited | Stroud | 2023 |
| CLIMB3R Ltd | Barrow-In-Furness | 2023 |
| Climbout CIC | London | 2024 |
| Clin-Assist Limited | Dronfield | 2016 |
| Clinic 103 Ltd | Stanmore | 2025 |
| Clinic 17 Ltd | Gateshead | 2024 |
| Clinic 20 Ltd | Swadlincote | 2023 |
| Clinic 22 NW Ltd | Wigan | 2022 |
| Clinic 22 Saltcoats Ltd | Saltcoats | 2018 |
| Clinic 27:7 Ltd | Thornton Heath | 2025 |
| Clinic 47 Ltd | Liverpool | 2022 |
| Clinic 59 Limited | Dunfermline | 2025 |
| Clinic 65 Ltd | Castleford | 2020 |
| Clinic AR Limited | London | 2023 |
| Clinic by KC Ltd | Ocean Way | 2021 |
| Clinic C Health & Aesthetics Ltd | Aberdeen | 2022 |
| Clinic C Ltd | Bedlington | 2025 |
| Clinic Care Ltd | Manchester | 2021 |
| Clinic Club Three Limited | London | 2025 |
| Clinic Clubhouse Limited | Brentwood | 2024 |
| Clinic Consultancy Ltd | London | 2025 |
| Clinic Holdings (UK) Limited | London | 2017 |
| Clinic Hub 1 Ltd | Cardiff | 2025 |