| Cheshire Wills Ltd | Professional & scientific | 1990 |
| Chesterton Flat Management Limited | Administrative & support | 1992 |
| Cheynes Training Group Limited | Administrative & support | 2021 |
| Cheynes Training Limited | Education | 1997 |
| Chico Style Ltd | Construction | 2020 |
| Chiddinglye Estate Ltd | Agriculture & fishing | 2011 |
| Chiizone Limited | Extraterritorial | 2008 |
| Chimney Sweep Ltd | Administrative & support | 2025 |
| Chimneys & Roofs (South East) Ltd | Construction | 2017 |
| Chloe Nails EG Ltd | Other services | 2026 |
| Chloe Wicks Ltd | Arts & recreation | 2023 |
| Chocabox Gifts Ltd | Wholesale & retail | 2025 |
| Chocolate Lodge Limited | Manufacturing | 2017 |
| Choice Analysis Limited | Professional & scientific | 1997 |
| Christianna Interiors Limited | Real estate | 2017 |
| Christie Associates Ltd | Administrative & support | 2022 |
| Christopher Michael Beauty Ltd | Other services | 2024 |
| Chrome Flare Ltd | Wholesale & retail | 2026 |
| Church of Scientology (England and Wales) | Administrative & support | 1996 |
| Cirkel Design Limited | Professional & scientific | 2013 |
| Citizens' Commission on Human Rights (United Kingdom) | Health & social care | 2000 |
| CJL Professional Painting & Decorating Ltd | Construction | 2015 |
| Claig Company Limited | Professional & scientific | 2015 |
| Claimant Co Limited | Administrative & support | 2010 |
| Clara Luiza Hammond-Seaman Ltd | Extraterritorial | 2022 |
| Classic Car Storage (East Sussex) Limited | Transport & logistics | 2015 |
| Clat Logistics Limited | Transport & logistics | 2026 |
| Clat Solutions Limited | Construction | 2015 |
| Cleantide Cleaning & Maintenance Ltd | Construction | 2026 |
| Clearwater People Solutions Limited | Administrative & support | 2004 |
| Clima Mechanical Services Ltd | Construction | 2021 |
| Climate Change Capital Group ( Europe) Ltd | Professional & scientific | 2022 |
| Clive Norman Plastering Services Ltd | Construction | 2018 |
| Clouds MARK3TING Ltd | Professional & scientific | 2023 |
| Club Marketing One Ltd | Information & communication | 2023 |
| CM Marketing & PR Ltd | Professional & scientific | 2011 |
| CNC Accounting Services Limited | Professional & scientific | 2010 |
| CNM Business Limited | Administrative & support | 2023 |
| CNM the College of Naturopathic & Complementary Medicine Ltd | Education | 2001 |
| CNM the College of Naturopathic Medicine Limited | Administrative & support | 2009 |
| Co-Living by Design Limited | Real estate | 2020 |
| Coaching 4 Succes Ltd | Administrative & support | 2014 |
| Cocoa Beach Resort Brazil Limited | Hospitality | 2025 |
| Codecept Limited | Information & communication | 2015 |
| Codemind Ltd | Wholesale & retail | 2024 |
| Cogg Properties Limited | Real estate | 2024 |
| Colin Cradock Ltd | Professional & scientific | 2010 |
| Colwood Land Care Limited | Administrative & support | 2014 |
| Comber Holdings Limited | Financial services | 2025 |
| Comfort Cooling Ltd | Construction | 2021 |
| Comm Trans Ltd | Information & communication | 2013 |
| Commodity Capital Limited | Financial services | 2010 |
| Communicate Planning Limited | Professional & scientific | 2017 |
| Compliance Matters UK Limited | Administrative & support | 2004 |
| Compton-Stark Estates Limited | Real estate | 2024 |
| Concise Security Limited | Administrative & support | 2002 |
| Condale Plastics Limited | Manufacturing | 1970 |
| Connect Global Resourcing Solutions Limited | Administrative & support | 2025 |
| Conor Christian Property Limited | Real estate | 2023 |
| Constiaconsultancy Ltd | Construction | 2022 |
| Construct Group Holdings Limited | Financial services | 2019 |
| Construct Land & Homes (Ashurst) Limited | Construction | 2006 |
| Construct Land & Homes (Roydon) Limited | Construction | 2020 |
| Construct Land & Homes (Tewin) Limited | Construction | 2020 |
| Construct Land & Homes Limited | Construction | 2020 |
| Consulting in Business Limited | Professional & scientific | 2013 |
| Conteco Projects Limited | Construction | 2020 |
| Contibeque Developments Limited | Wholesale & retail | 2025 |
| Contrast UK Ltd. | Professional & scientific | 2005 |
| Cookieee Monsters Limited | Manufacturing | 2013 |
| Coombe Hall Management Company Limited | Households | 2001 |
| Copper Tops Plumbing and Heating Limited | Construction | 2026 |
| Copthorne Road (Felbridge) Management Company Limited | Households | 2008 |
| Copyhold 1963 Limited | Extraterritorial | 2013 |
| Cora Dance Limited | Information & communication | 2025 |
| Core Records Ltd | Extraterritorial | 2020 |
| Coriandoli Limited | Wholesale & retail | 1986 |
| Coulomb Consulting Ltd | Professional & scientific | 2023 |
| County Flow Limited | Professional & scientific | 2021 |
| Courtlands (Sharpthorne) Limited | Real estate | 2005 |
| Couture CH' NE Sais Quoi Ltd | Wholesale & retail | 2024 |
| Cowan Architects Ltd. | Professional & scientific | 1989 |
| Coyote Consulting Limited | Professional & scientific | 2015 |
| CP Metal Traders Ltd | Wholesale & retail | 2013 |
| Craft Trading Limited | Other services | 2022 |
| Crafted Spaces Sussex Ltd | Construction | 2026 |
| Cranfield Lodge Freehold Limited | Households | 2018 |
| Cranston Gardens (East Grinstead) Management Limited | Households | 2007 |
| Craven Construction Services Ltd | Construction | 2026 |
| Crawley Emergency Vets Ltd | Professional & scientific | 2013 |
| CRE8TIVE Property Services Ltd | Households | 2024 |
| Created Space Limited | Construction | 2009 |
| Created Space Properties Ltd | Real estate | 2025 |
| Creatisity Labs UK Limited | Wholesale & retail | 2025 |
| Creative Ginger Ltd | Arts & recreation | 2017 |
| Creative Media Agency Ltd | Professional & scientific | 2022 |
| Crescent Road Association of Maisonette Properties Limited | Households | 1995 |
| Criminon United Kingdom | Education | 2003 |
| Crisp Enterprises (Rusper) Limited | Real estate | 2019 |
| Crowcombe Court Venue Limited | Hospitality | 2019 |