| Construct Construction Limited | Construction | 2024 |
| Contextpath Limited | Information & communication | 2026 |
| Contracom Limited | Information & communication | 2007 |
| Contractpoint Limited | Professional & scientific | 2012 |
| Control Kitchen Bathroom and Boiler Installations Ltd | Construction | 2019 |
| Convert Energy Ltd | Construction | 2014 |
| Cooke and Cooke Ltd | Information & communication | 2017 |
| Cool Retail Ltd | Wholesale & retail | 2023 |
| Cooll Contracting Ltd | Transport & logistics | 2019 |
| Coombe Wood Construction Ltd | Construction | 2025 |
| Coombes Consultancy Services Limited | Professional & scientific | 2022 |
| Cooper Family Properties Limited | Real estate | 2024 |
| Cooper-Clark Development Co. Limited | | 1975 |
| Coopers Enterprise Ltd | Transport & logistics | 2019 |
| Copperhead Productions Ltd | Arts & recreation | 2011 |
| Coppwear Ltd | Manufacturing | 2023 |
| Cor-Kinetic Limited | Other services | 2023 |
| Coral Eyewear Ltd | Manufacturing | 2019 |
| Corbin Properties Ltd | Real estate | 2023 |
| Corcillum Investments Ltd | Professional & scientific | 2014 |
| Cordia Group Ltd | Professional & scientific | 2020 |
| Core Fruit Products Limited | Manufacturing | 2001 |
| Core Property Investments Limited | Real estate | 2015 |
| Corinthian Affinity Solutions Limited | Administrative & support | 2015 |
| Corinthian Benefits Consulting Limited | Financial services | 2016 |
| Corinthian Group Holdings Limited | Administrative & support | 2018 |
| Cork Farm Equestrian Limited | Wholesale & retail | 2017 |
| Corkk Ltd | Wholesale & retail | 2019 |
| Corn Store Events Ltd | Real estate | 2024 |
| Corner Coffee House TMH Ltd | Wholesale & retail | 2026 |
| Cornerglade Limited | Hospitality | 2025 |
| Cornhill Social Impact Alliance Limited | Financial services | 2026 |
| Cornwallis Super Market Ltd | Wholesale & retail | 2026 |
| Costratify Limited | Information & communication | 2019 |
| Cottage Concepts Ltd | Wholesale & retail | 2023 |
| Cottage I Company Limited | Arts & recreation | 2022 |
| Country Campers Limited | Manufacturing | 2016 |
| Country Heights Ltd | Construction | 2022 |
| Country Pet Cremations Ltd | Other services | 2025 |
| Country Textile Ltd | Wholesale & retail | 2019 |
| County Associates (UK) Employee Benefits Ltd | Administrative & support | 2015 |
| County Associates (UK) LLP | | 2010 |
| County Bidco Limited | Financial services | 2020 |
| County Midco Limited | Financial services | 2020 |
| County Topco Limited | Financial services | 2020 |
| Coupemedical Ltd | Professional & scientific | 2024 |
| Court Mount Park Homes Limited | Hospitality | 2019 |
| Courtstairs Manor Ltd | Real estate | 2019 |
| Cousins Lounge Limited | Hospitality | 2024 |
| Covert Wood Ltd | Real estate | 2026 |
| Cowe H Consulting Limited | Information & communication | 2011 |
| Cowin Building Contractors Limited | Construction | 2003 |
| Cowin Holdings Limited | Professional & scientific | 2007 |
| Cowling & Wilcox Limited | Wholesale & retail | 1960 |
| Cozikent Ltd | Construction | 2025 |
| CP Global Limited | Professional & scientific | 2000 |
| CP Industries Ltd | Information & communication | 2022 |
| Cpddconsulting Ltd | Professional & scientific | 2020 |
| Cpdi Ltd | Education | 2022 |
| CPE Group Services Limited | Construction | 2026 |
| CPN Plumbing Ltd | Construction | 2017 |
| CPS Brickwork Ltd | Construction | 2025 |
| CPT Investments Limited | Real estate | 2011 |
| CR Utility Services Ltd | Construction | 2017 |
| Crabtree & Crabtree (Aldington) Limited | Construction | 2015 |
| Crabtree & Crabtree (Detling) Limited | Construction | 2015 |
| Crabtree & Crabtree (Harrietsham) Limited | Construction | 2014 |
| Crabtree & Crabtree (Newington) Limited | Construction | 2014 |
| Crabtree & Crabtree (Smarden) Limited | Construction | 2015 |
| Craven Street Capital Holdings Limited | Financial services | 2016 |
| Craven Street Financial Planning Limited | Financial services | 1999 |
| Craven Street Wealth Limited | Professional & scientific | 2020 |
| Crazyshop Ltd | Wholesale & retail | 2025 |
| CRC Deliveries Ltd | Transport & logistics | 2024 |
| CRE8 Hoaden Limited | Hospitality | 2020 |
| CRE8 Island Views Limited | Hospitality | 2016 |
| CRE8 Nantyffin Limited | Hospitality | 2023 |
| CRE8 OPS Limited | Hospitality | 2020 |
| CRE8 Property Ltd | Administrative & support | 2016 |
| Create a Cabin Limited | Manufacturing | 2014 |
| Creative Clicks Limited | Professional & scientific | 2007 |
| Creative Design 3D Limited | Professional & scientific | 2024 |
| Creativity Travel Limited | Administrative & support | 2002 |
| Creekside 2020 Limited | Construction | 2019 |
| Creekside Developments (Faversham) Limited | Construction | 2016 |
| Creet Lakes Ltd | Agriculture & fishing | 2024 |
| Crepes@ Ltd | Hospitality | 2022 |
| Crescent Investments (Beta) Ltd | Financial services | 2021 |
| Crescent New Homes Ltd | Real estate | 2025 |
| Crezom Limited | Construction | 2025 |
| Crfc Catering Limited | Hospitality | 2025 |
| CRH Sustainability Group Ltd | Wholesale & retail | 2020 |
| Criss&Roby Transport and Recovery Limited | Transport & logistics | 2025 |
| Crittenden Commercial Limited | Real estate | 2008 |
| Crofts Wood Limited | Real estate | 2015 |
| Cronin Management Services Limited | Professional & scientific | 2018 |
| Cross Channel Logistics Limited | Transport & logistics | 2007 |
| Crosskeys Ventures Ltd | Real estate | 2025 |
| Crowdmint Ltd | Financial services | 2016 |
| Crown Property Maintenance Limited | Construction | 2010 |