| Carbon Impact Ltd | Professional & scientific | 2021 |
| Carmella Terrana Agency Ltd | Administrative & support | 2009 |
| Casa Grande Limited | Wholesale & retail | 2005 |
| Castle Estates (Property Management Services) Ltd | Real estate | 2011 |
| Castle Estates (Staffordshire) Limited | Real estate | 1999 |
| Castle Holding Group Ltd | Financial services | 2009 |
| Castlewood Homes & Developments Ltd | Construction | 2023 |
| Category - Insight (U.K.) Limited | Professional & scientific | 2007 |
| Cavendish Design & Advertising Limited | Arts & recreation | 1970 |
| CB Sports Performance Limited | Health & social care | 2014 |
| CBR Roads Ltd. | Extraterritorial | 2008 |
| CCP Developments (Stone) Holdings Ltd | Financial services | 2022 |
| CCP Developments (Stone) Limited | Construction | 2017 |
| CDL Properties Rugeley Ltd | Real estate | 2024 |
| CDR Training Ltd | Professional & scientific | 2014 |
| Celeski London Ltd | Wholesale & retail | 2025 |
| Celik Food Ltd | Hospitality | 2025 |
| Cema International Limited | Wholesale & retail | 2004 |
| Central Art Safe Ltd | Transport & logistics | 2021 |
| Central Electrical Distributors Ltd | Wholesale & retail | 2019 |
| Central Environmental Services Limited | Administrative & support | 1998 |
| Central Improvements Limited | Administrative & support | 2017 |
| Central Insulation & Environmental Services Limited | Financial services | 2001 |
| Central-Safe Ltd | Real estate | 2020 |
| Centric HR Limited | Administrative & support | 2016 |
| Ceramic Techniques Limited | Health & social care | 2014 |
| Cerberus Services Limited | Administrative & support | 2004 |
| Cerberus Software Solutions Ltd | Information & communication | 2008 |
| Ceri (Wolverhampton) Limited | Construction | 2002 |
| CH Accountancy Training Ltd | Education | 2020 |
| CH Splcing Ltd | Information & communication | 2026 |
| Chandler Contractors Ltd | Construction | 2020 |
| Charles Titch Precision Ltd | Manufacturing | 2017 |
| Charlotte Martin HR Ltd | Administrative & support | 2009 |
| Charming Carriages Limited | Transport & logistics | 2025 |
| Charterfield Accountancy Services Ltd | Professional & scientific | 2014 |
| Charteris Saints Limited | Other services | 2016 |
| Chase Achievement Ltd | Education | 2022 |
| Chase Arts (Central) Limited | Administrative & support | 2010 |
| Chase Autopaints Limited | Wholesale & retail | 2002 |
| Chase Cars Office Limited | Transport & logistics | 2018 |
| Chase Catering Limited | Hospitality | 2024 |
| Chase OWL Estates Ltd | Real estate | 2018 |
| Chase Tech Limited | Other services | 2019 |
| Chase the Adventure Escape Rooms Ltd | Arts & recreation | 2025 |
| Chaseley House Management Limited | Households | 2017 |
| Chaseley Limited | Households | 2017 |
| Chaseside Property Ltd | Real estate | 2021 |
| Chasestitch Limited | Manufacturing | 2023 |
| Chatabox Training Academy Ltd | Education | 2026 |
| Cherished Radiators Limited | Manufacturing | 2001 |
| Cherishers 811 Home Care Limited | Real estate | 2021 |
| Chestall Estates Ltd | Agriculture & fishing | 2026 |
| Chestall Properties Limited | Real estate | 2014 |
| Chestell Finance Ltd | Real estate | 2026 |
| Children First Consultancy Limited | Education | 2020 |
| Chillee Limited | Construction | 2010 |
| Chris Clarke Ltd | Professional & scientific | 2018 |
| Chris Proctor Limited | Extraterritorial | 2013 |
| Cifa Property Holdings Limited | Real estate | 2020 |
| Cifa+ Limited | Financial services | 2018 |
| Circle Mobile Limited | Wholesale & retail | 2022 |
| City GAS and Electrical Services Limited | Administrative & support | 2007 |
| CJ Horizons Ltd | Extraterritorial | 2014 |
| CJ Property Holdings Limited | Real estate | 2015 |
| CJ Wealth Ltd | Wholesale & retail | 2015 |
| CJL Reinforcements Limited | Professional & scientific | 2021 |
| CJS Automation Ltd | Wholesale & retail | 2023 |
| Cl-R Services Ltd | Professional & scientific | 2023 |
| Clair's Emporium Ltd | Wholesale & retail | 2021 |
| Claire Lopez Promotions Limited | Other services | 2024 |
| Clarke and Family Housing Limited | Real estate | 2020 |
| Classic Ibiza Limited | Administrative & support | 2022 |
| Clear Enterprises Ltd | Wholesale & retail | 2014 |
| Clear Fit Installations Limited | Construction | 2025 |
| Clearaco Limited | Construction | 1994 |
| Cleggs Property Management Limited | Real estate | 2012 |
| Clickit Group Ltd | Wholesale & retail | 2022 |
| Clkr Holdings Limited | Hospitality | 2020 |
| Coach Sports (London) Ltd | Arts & recreation | 2010 |
| Coastal Stays Ltd | Real estate | 2024 |
| Cobra Door Systems Ltd | Construction | 2017 |
| Cockbill Grant Limited | Construction | 2004 |
| Coco Tech Limited | Information & communication | 2013 |
| Codeace Limited | Information & communication | 1989 |
| Colton Local Nature Reserve | Arts & recreation | 2012 |
| Colton Oaks Ltd | Construction | 2021 |
| Commercial and Leisure Land Services Limited | Construction | 1999 |
| Commercial Initiatives Limited | Professional & scientific | 2001 |
| Commodity Drop Ltd | Construction | 2018 |
| COMMUNICATE2U Ltd | Other services | 2011 |
| Community Advice Service Limited | Administrative & support | 2016 |
| Community Advice Service London Limited | Administrative & support | 2010 |
| Companach Limited | Administrative & support | 2025 |
| Complete Aluminium Solutions Limited | Manufacturing | 2021 |
| Complete Aluminium Spares Limited | Construction | 2018 |
| Complete Engine Export Solutions Ltd | Wholesale & retail | 2016 |
| Complete Fire Care Limited | Public administration | 2023 |
| Concept Quantity Surveying Ltd | Professional & scientific | 2026 |
| Confederation of Tourism & Hospitality Limited | Education | 1987 |