| C&M Investments Limited | Real estate | 2018 |
| C&N Eagle Ltd | Hospitality | 2022 |
| C&S Maintenance and Landscaping Ltd | Administrative & support | 2019 |
| C-Prio Ltd | Information & communication | 2022 |
| C. H. Building Designs Ltd | Professional & scientific | 2010 |
| C. J. H. Farming Limited | Agriculture & fishing | 1995 |
| C. Rayner Limited | Extraterritorial | 2016 |
| C.F.Anderson & SON Limited | Real estate | 1925 |
| C.T.D.C. Limited | Professional & scientific | 1995 |
| C21 Window Cleaning & Maintenance Ltd | Administrative & support | 2022 |
| C4S Print Management Limited | Wholesale & retail | 2021 |
| C4SM Ltd | Real estate | 2021 |
| CA Gardening Services Ltd | Other services | 2023 |
| CAA Resources Ltd | Health & social care | 2020 |
| CAB City Ltd | Transport & logistics | 2025 |
| Cabalie Ltd | Information & communication | 2020 |
| Cadeby Stone Limited | Administrative & support | 2002 |
| Cadmus Distribution Group Holdings Limited | Financial services | 2020 |
| Cadmus Distribution Group Limited | Administrative & support | 2018 |
| Cadmus Products International Limited | Extraterritorial | 2022 |
| Cadmus Products Limited | Financial services | 2024 |
| Caer Beris Holiday Park Limited | Hospitality | 2000 |
| Cafe Deli Holdings Limited | Financial services | 2024 |
| Cafe Macchiato Ltd | Hospitality | 2017 |
| Cafe Ossaaga Ltd | Hospitality | 2019 |
| Cafe Virage Ltd. | Extraterritorial | 2010 |
| Caglit Limited | Information & communication | 2015 |
| CAH Services and Holdings Ltd | Wholesale & retail | 2019 |
| Cairo Apollo Ltd | Professional & scientific | 2026 |
| Cajaco IT Services Ltd | Information & communication | 2014 |
| Caldwell Electrical Ltd | Construction | 2023 |
| Caleb Rayner Holdings Limited | Professional & scientific | 1982 |
| Caleb Rayner Limited | Agriculture & fishing | 1923 |
| Cali Consultant Limited | Professional & scientific | 2024 |
| Cali Guidance Limited | Professional & scientific | 2023 |
| Caliber Group Ltd | Administrative & support | 2017 |
| Caliber Homes Ltd | Real estate | 2020 |
| Calibre Hiring Limited | Administrative & support | 2023 |
| Calimae Ltd | Wholesale & retail | 2025 |
| Call of the Wild ZOO Limited | Arts & recreation | 2021 |
| Calm Creative Limited | Professional & scientific | 2012 |
| Calm Spring Limited | Hospitality | 2022 |
| Caltekin Consultancy and Investment Limited | Professional & scientific | 2025 |
| Calver Plant & Vehicle Services Ltd | Wholesale & retail | 2024 |
| CAM Agricultural Consultancy Ltd | Professional & scientific | 2020 |
| CAM Facilities Limited | Administrative & support | 2011 |
| CAM Testing & Electrical Services Ltd | Construction | 2020 |
| Camatics Ltd | Wholesale & retail | 2014 |
| Cambria Solutions Group Holdings Limited | Financial services | 1992 |
| Cambridge Biosolutions Ltd | Professional & scientific | 2021 |
| Cambridge Courts (UK) LLP | | 2014 |
| Cambridge Flair Limited | Information & communication | 2022 |
| Cambridge Pacific Limited | Professional & scientific | 2020 |
| Camello Property Services Ltd | Real estate | 2020 |
| Camera World Holdings Limited | Financial services | 2019 |
| Camera World Limited | Wholesale & retail | 1999 |
| Cammack & Wilcox Limited | Other services | 1994 |
| Cammas Hall Fruit Farm Limited | Agriculture & fishing | 2014 |
| Camouflage Junkie Ltd | Wholesale & retail | 2019 |
| Camp Beaumont Asia Limited | Professional & scientific | 2018 |
| Camp Beaumont Day Care Limited | Education | 1991 |
| Camp Beaumont Group Limited | Financial services | 2025 |
| Campbell's Maintenance Services Ltd | Other services | 2026 |
| Camper Convert Ltd | Professional & scientific | 2020 |
| Camsoft Solutions UK Limited | Information & communication | 2019 |
| CAN Marketing Limited | Wholesale & retail | 2020 |
| Canal Street Productions Limited | Information & communication | 2002 |
| Canaveral Limited | Construction | 2019 |
| Candodigital Limited | Extraterritorial | 2001 |
| Candomedia Limited | Professional & scientific | 2001 |
| Canfield Electrical Services Ltd | Construction | 2024 |
| Canfield Land Co Ltd | Real estate | 2010 |
| Canford Marketing Limited | Professional & scientific | 2024 |
| Canna Retail Limited | Wholesale & retail | 2018 |
| Canonium Financial Limited | Financial services | 2022 |
| Canside Management Limited | Households | 2014 |
| Canthorpe Limited | Real estate | 1995 |
| Cantily Construction Limited | Construction | 2007 |
| Canvasflow Limited | Information & communication | 2015 |
| CAP Growth Partners Limited | Administrative & support | 2018 |
| Capcel Ltd | Wholesale & retail | 2025 |
| Cape (Electrical & Mechanical) Group Ltd | Financial services | 2022 |
| Cape Enchantment Ltd | Manufacturing | 2023 |
| Capital & Counties (Financial Services) Limited | Financial services | 1986 |
| Capital & Counties (Insurance Consultants) Limited | Financial services | 1987 |
| Capital & Counties Group Limited | Professional & scientific | 1987 |
| Capital Containers Limited | Transport & logistics | 2018 |
| Capital Contract Flooring Limited | Construction | 2026 |
| Capital Dynamics Group Limited | Other services | 2019 |
| Capital Forum(Uk) Limited | Real estate | 2017 |
| Capital Investments Holding Ltd | Financial services | 2024 |
| Capital IT Services Ltd | Wholesale & retail | 2015 |
| Capital Plastering & Rendering Ltd | Construction | 2025 |
| Capital Properties Essex Ltd | Real estate | 2024 |
| Capital Renders Limited | Construction | 2022 |
| Capital Roofing Ltd | Construction | 2014 |
| Capital Square (Chelmsford) Residents Company Limited | Households | 2003 |
| Capital Training Solutions Ltd | Administrative & support | 2013 |
| Capital UK Limited | Administrative & support | 2006 |
| Cappafe Ltd | Wholesale & retail | 2024 |