| C.I. Claims Ltd | Financial services | 2011 |
| C.M. (Wimbledon) Company Limited | Households | 2000 |
| C.R. Barron (Meats) Limited | Wholesale & retail | 1956 |
| C.R. Barron (Midlands) Limited | Wholesale & retail | 1974 |
| C.R.Barron Limited | Wholesale & retail | 1954 |
| Cabledrive Limited | Information & communication | 2012 |
| Cablewise Projects Ltd | Construction | 2022 |
| Caddington House Management Company Ltd | Households | 2024 |
| Cadence Park (EA) Management Company Limited | Households | 2006 |
| Cadenza Court (Witham) Management Company Limited | Households | 2002 |
| Cadogan House Residents Limited | Households | 1983 |
| Cafe Thyme Limited | Hospitality | 2013 |
| Cafe Vita Ltd | Hospitality | 2025 |
| Calbert Contractors Limited | Construction | 2024 |
| Calder Grange (Billington) Management Company Limited | Households | 2022 |
| Calder Heights (Netherton) Management Company Limited | Households | 2006 |
| Calderstones Park Management Company Limited | Households | 2001 |
| Caledonia Life Sciences Ltd | Professional & scientific | 2024 |
| Calfatec Limited | Professional & scientific | 2016 |
| Calissy Limited | Wholesale & retail | 2021 |
| Calverstone Park (Rugby) Management Company Limited | Households | 2005 |
| Cambridge Court (Puckeridge) Management Company Limited | Households | 2005 |
| Cambridge Court (Soham) Residents Association Limited | Households | 1991 |
| Cambridge Green Management Company Limited | Households | 2025 |
| Cambridge Road (Fenstanton) Management Company Limited | Households | 2017 |
| Cambridge Road (Long Melford) Management Company Limited | Households | 2017 |
| Canada Cleaning Services Limited | Administrative & support | 2000 |
| Canal View (Garstang) Management Company Limited | Households | 2014 |
| Canalside (Aylesbury) Management Company Limited | Households | 2014 |
| Canalside 2 (Aylesbury) Residents Management Company Limited | Households | 2016 |
| Canfield Carpentry Ltd | Manufacturing | 2018 |
| Cankarakaya Ltd | Wholesale & retail | 2025 |
| Cannabac Ltd | Construction | 2019 |
| Cannon Growth Consultancy Ltd | Professional & scientific | 2025 |
| Canon Court Fair Oak Management Limited | Households | 1982 |
| Cape Heritage Holdings Limited | Construction | 2014 |
| Cape Kennington Limited | Real estate | 2011 |
| Capital Airconditioning Limited | Construction | 2007 |
| Capital Coldstores and Insulation Limited | Wholesale & retail | 1993 |
| Capital Connexion Management Company (Bedford) Limited | Households | 2005 |
| Capital Refrigeration Limited | Wholesale & retail | 2009 |
| Capital Refrigeration Services Limited | Construction | 1967 |
| Capitol Airconditioning Limited | Construction | 2007 |
| Capsys Ltd | Information & communication | 2026 |
| Card Legacy Limited | Wholesale & retail | 2025 |
| Card Reserve Limited | Wholesale & retail | 2026 |
| Cardean Electrical Services Limited | Construction | 2016 |
| Career Academy Limited | Administrative & support | 2016 |
| Carernotes Ltd | Information & communication | 2025 |
| Caribbean Ltd | Hospitality | 2022 |
| Carinthia Place Management Company Limited | Households | 2013 |
| Carleton House Management Limited | Households | 2014 |
| Carlisle Road Management Company (Romford) Limited | Households | 2001 |
| Carlton Mansions Limited | Households | 2000 |
| Carlyon Bay Management Company Limited | Households | 2002 |
| Carr Lane Services Ltd | Real estate | 2016 |
| Carringtons Residential Management Limited | Real estate | 2006 |
| Carringtons Secretarial Services Limited | Extraterritorial | 2009 |
| Carter Squared Limited | Professional & scientific | 2015 |
| Cartrefle Apartments Management Company Limited | Households | 2012 |
| Cartwright Telephony Limited | Information & communication | 2008 |
| CAS Welding & Fabrication Ltd | Construction | 2009 |
| Casa TAG Ltd | Real estate | 2017 |
| Caspian Kebab Ltd | Hospitality | 2025 |
| Cassier Recruitment Limited | Administrative & support | 2023 |
| Cast Iron Productions Limited | Information & communication | 2015 |
| Castle Court (Portland) Management Company Limited | Households | 2018 |
| Castle Hill (Barratt) Residents Management Company Limited | Households | 2016 |
| Castle Hill (DWH1) Residents Management Company Limited | Households | 2017 |
| Castlegate Holdings (Herts) Limited | Real estate | 1994 |
| Catalina Investments Limited | Financial services | 2016 |
| Cathedral View (Phase 4) ELY Management Company Limited | Households | 2006 |
| Cathedral Works Organisation Limited | Professional & scientific | 2016 |
| Causeway Life Sciences Consultants Ltd | Professional & scientific | 2015 |
| Cavalry Fields Management Limited | Households | 1988 |
| Cavendish Asset Group Limited | Real estate | 2026 |
| Cavendish Gardens (Widnes) Management Company Limited | Households | 2007 |
| Cavendish Joinery Limited | Manufacturing | 1991 |
| Caviro Ltd | Real estate | 2014 |
| Cawson Limited | Real estate | 2006 |
| CBR Properties Ltd | Real estate | 2021 |
| CCA Store Ltd | Wholesale & retail | 2024 |
| Cctl Limited | Transport & logistics | 2019 |
| CDF Drylining Supplies Ltd | Construction | 2015 |
| Cedar Lodge (Oakley Road Southampton) Management Company Limited | Households | 2005 |
| Cedro (EA) Management Company Limited | Households | 2007 |
| Celestial Scripts Ltd | Information & communication | 2022 |
| Cell Barnes Limited | Construction | 2015 |
| Celsius Second Limited | Information & communication | 1938 |
| Centauri Limited | Information & communication | 2016 |
| Cerimonia Ltd | Real estate | 2015 |
| Ceylon Breeze Ltd | Hospitality | 2023 |
| Cffoods Ltd | Hospitality | 2021 |
| CG Future Developments Limited | Real estate | 2023 |
| CGH Management Limited | Households | 2003 |
| Chambers Street Hertford Limited | Real estate | 2023 |
| Chandlers Court (Watford) Management Company Limited | Households | 2003 |
| Chapel Heights Management Company Limited | Households | 2014 |
| Chapple Financial Services Limited | Professional & scientific | 2022 |
| Chapple Motors Limited | Wholesale & retail | 2006 |