| CHP Investments 3 Limited | Real estate | 2022 |
| CHP Investments 4 Limited | Real estate | 2022 |
| Chris Bowers Cars Ltd | Wholesale & retail | 2024 |
| Chris Lelliott Limited | Information & communication | 2025 |
| Chris M Computers Ltd | Wholesale & retail | 2011 |
| Chris Mcfaul Ltd | Professional & scientific | 2021 |
| Chris Neville Ltd | Other services | 2014 |
| Chris Puttock Ltd | Construction | 2023 |
| Chris Shaw Consulting Services Ltd | Professional & scientific | 2026 |
| Chrissy Campbell Coaching Ltd | Health & social care | 2026 |
| Christchurch Specsavers Hearcare Limited | Wholesale & retail | 2006 |
| Christchurch Specsavers Limited | Wholesale & retail | 2000 |
| Christopher Lyne Limited | Arts & recreation | 2015 |
| Christopher Pambou Ltd | Administrative & support | 2020 |
| Chrobe Properties Ltd | Real estate | 2024 |
| Chrome Technologies (Holdings) Limited | Wholesale & retail | 2022 |
| Chrome Telecom Limited | Information & communication | 2014 |
| Chrysalis CV Limited | Administrative & support | 2015 |
| Chumphrey Limited | Financial services | 2016 |
| Church House (CH) Filton Limited | Construction | 2021 |
| Church House Building Management Limited | Households | 2023 |
| Churchers Solicitors LLP | | 2019 |
| Churchill Electrical Services Ltd | Professional & scientific | 2020 |
| Chute Lodge Limited | Other services | 2018 |
| Chuy Accounts Ltd | Professional & scientific | 2014 |
| Chx.Life Limited | Other services | 2018 |
| Ciarajade Hair Salon Ltd | Other services | 2021 |
| Cicero Property Ltd | Real estate | 2016 |
| Cicho Limited | Wholesale & retail | 2024 |
| Cidron Morrison Bidco Limited | Financial services | 2026 |
| Cidron Victor Bidco Limited | Financial services | 2026 |
| Cidron Victor Midco Limited | Financial services | 2026 |
| CIE Management Services Limited | Other services | 2014 |
| CIM Services Ltd | Manufacturing | 2026 |
| Cinderella's Closet UK Ltd | Wholesale & retail | 2022 |
| Circadian Arts Ltd | Wholesale & retail | 2024 |
| Circle Stock Ltd | Wholesale & retail | 2021 |
| Circu Limited | Other services | 2000 |
| Circu Management Ltd | Real estate | 2024 |
| Circular Autos Limited | Wholesale & retail | 2011 |
| Circus World Entertainment Ltd | Arts & recreation | 2011 |
| Cirencester Specsavers Hearcare Limited | Wholesale & retail | 2017 |
| Cirencester Specsavers Limited | Wholesale & retail | 2004 |
| Cirencester Visionplus Limited | Wholesale & retail | 2004 |
| Citizen Properties Ltd | Real estate | 2019 |
| Citrine Care Consultants Ltd | Professional & scientific | 2025 |
| Citrus People Limited | Professional & scientific | 2017 |
| City Locks Limited | Construction | 2003 |
| City Physiotherapy Centre Ltd | Health & social care | 2007 |
| Citys Network Limited | Professional & scientific | 1997 |
| Civili Limited | Administrative & support | 2025 |
| CJ Consultancy 365 Ltd | Professional & scientific | 2023 |
| CJC Events Ltd | Other services | 2017 |
| CJE Business Services Limited | Information & communication | 2017 |
| Cjgcompany Ltd | Wholesale & retail | 2024 |
| Cjnsocial Ltd | Professional & scientific | 2024 |
| CJP Chauffeur Cars Ltd | Transport & logistics | 2009 |
| CJT Consulting (Services) Ltd | Professional & scientific | 2014 |
| CJT Plant Services Ltd | Manufacturing | 2026 |
| Ckrb Heating Services Limited | Construction | 2016 |
| Cl@Rity.Info Ltd | Professional & scientific | 2026 |
| Clacton Specsavers Hearcare Limited | Wholesale & retail | 2017 |
| Claire Emily Rutherford Limited | Hospitality | 2025 |
| Claire Rena Saunders Ltd | Real estate | 2020 |
| Clam B Ltd | Agriculture & fishing | 2020 |
| Clamp Farm Storage Ltd | Transport & logistics | 2024 |
| Clapham Specsavers Hearcare Limited | Wholesale & retail | 2022 |
| Clapham Specsavers Limited | Wholesale & retail | 1995 |
| Clapham Visionplus Limited | Wholesale & retail | 2002 |
| Clare Beresford Properties Ltd | Real estate | 2020 |
| Clareflow Management Ltd | Real estate | 2025 |
| Clarity Care Consulting Limited | Administrative & support | 2009 |
| Clarity Resolve Ltd | Real estate | 2026 |
| Clark Trading Limited | Financial services | 2014 |
| Clarke Psychology Services Limited | Health & social care | 2009 |
| Clarke Water Hygiene Limited | Water & waste | 2024 |
| Clarks Auto Service Limited | Wholesale & retail | 2011 |
| Classic Acquisitions Limited | Financial services | 2024 |
| Classique School of Dance Limited | Arts & recreation | 2012 |
| Clay & Pebble Properties Limited | Real estate | 2025 |
| Clayford Warehouse Units Ltd | Real estate | 2020 |
| Claylands Hire Limited | Extraterritorial | 2002 |
| Claylands Park Management Company Limited | Real estate | 2005 |
| CLB Investments Limited | Real estate | 2024 |
| Clean Island Limited | Water & waste | 2016 |
| Cleaner Homes Ltd | Real estate | 2020 |
| Cleanheels Limited | Wholesale & retail | 2008 |
| Cleaning Matters 2 US Limited | Professional & scientific | 2008 |
| Cleansing Service (Southern Counties) Limited | Extraterritorial | 1950 |
| Cleansing Service Group (Recovery) Limited | Water & waste | 1962 |
| Cleansing Service Group (Rushton) Limited | Extraterritorial | 1985 |
| Cleansing Service Group (Tank Cleaning) Limited | Extraterritorial | 1972 |
| Cleansing Service Group (Wilton) Limited | Water & waste | 2010 |
| Cleansing Service Group Limited | Professional & scientific | 1954 |
| Cleantec (Midlands) Limited | Other services | 2017 |
| Clear EAR WAX Specialist Limited | Health & social care | 2026 |
| Clear Eco Ltd | Construction | 2024 |
| Clearer Lead Limited | Professional & scientific | 2023 |
| Clearview Glass & Conservatories Limited | Construction | 2023 |
| Cleckheaton Specsavers Limited | Wholesale & retail | 2018 |