| Carmichael Asset Management Limited | Administrative & support | 2011 |
| Carol's Candles and Gifts Ltd | Wholesale & retail | 2023 |
| Carouse Limited | Wholesale & retail | 2021 |
| Carousel Distribution Limited | Transport & logistics | 2025 |
| Carpetcore Limited | Other services | 2025 |
| Carpony Domestic Carports Ltd | Construction | 2026 |
| Cars - Chris's Auto Repairs Services Ltd | Wholesale & retail | 2013 |
| Cars - Investments Limited | Wholesale & retail | 2025 |
| Cars - MOT Centre Ltd | Wholesale & retail | 2024 |
| Cars 2 Trucks Ltd | Transport & logistics | 2019 |
| Carwash & Mechanic Equipments Ltd | Wholesale & retail | 2023 |
| Caskade Consulting Ltd | Information & communication | 2019 |
| Caskade Technologies Limited | Information & communication | 2018 |
| Cassian Trans Ltd | Transport & logistics | 2018 |
| Castle Hills Eaton Socon Management Company Limited | Extraterritorial | 2004 |
| Catalyst Business Services Limited | Other services | 2025 |
| Catalyst Road Human Resources Limited | Professional & scientific | 2016 |
| Catapult Growth Fund Limited | Financial services | 2006 |
| Catapult Growth Fund Limited Partnership | | 2006 |
| Catapult Growth Managers GP Limited | Financial services | 2006 |
| Catapult Holdings Limited | Financial services | 2005 |
| Catapult Life Sciences GP LLP | | 2015 |
| Catapult Ultimate Holdings Limited | Financial services | 2013 |
| Catapult Venture Managers Limited | Financial services | 1999 |
| Catering Equipment Rentals Limited | Administrative & support | 2015 |
| Cath Carter Limited | Wholesale & retail | 2023 |
| Catpig Ltd | Information & communication | 2018 |
| Catpig Properties Ltd | Real estate | 2022 |
| Caudwell Farms | Agriculture & fishing | 1951 |
| Caviam Consulting Limited | Professional & scientific | 2025 |
| Cazz Healthcare Services Ltd | Health & social care | 2026 |
| CB Studios (South Holland) Ltd | Real estate | 2016 |
| CBP Maintenance Ltd | Construction | 2025 |
| CC Premier Roofing Ltd | Construction | 2022 |
| CCM Shipping Ltd | Transport & logistics | 2024 |
| CCN Logistics Ltd | Administrative & support | 2016 |
| CCR Interiors Limited | Wholesale & retail | 2025 |
| CCS Transport (Lincs) Ltd | Transport & logistics | 2021 |
| Cctv-Homeprotect Limited | Manufacturing | 2019 |
| CD Holdings Group Ltd | Financial services | 2020 |
| CD Services (Donington) Ltd | Professional & scientific | 2022 |
| CD Trans (Peterborough) Ltd | Transport & logistics | 2021 |
| Cdap Construction Ltd | Construction | 2024 |
| CDH Academy CIC | Arts & recreation | 2025 |
| CDJ Driver Hire Ltd | Transport & logistics | 2014 |
| CDM Haulage Limited | Transport & logistics | 2018 |
| CDS Labour (Acquisitions 2024) Ltd | Transport & logistics | 2017 |
| CDS Labour (Farming) Ltd | Administrative & support | 2013 |
| CDS Labour (Group UK) Ltd | Administrative & support | 2017 |
| CDS Labour (Marketing) Ltd | Administrative & support | 2020 |
| CDS Labour Fair-Responsible-Ethical-Diverse Ltd | Administrative & support | 2018 |
| Cece's Mobile Catering Limited | Hospitality | 2024 |
| Cece's Takeaway Limited | Hospitality | 2024 |
| Cecil Francis Limited | Construction | 1958 |
| Cedar Homes (Lincs) Ltd | Real estate | 2025 |
| Cedar Oaks Tree Care Ltd | Administrative & support | 2024 |
| Cedar Tree Services Ltd | Administrative & support | 2025 |
| Celador Estates Limited | Real estate | 2021 |
| Celestial Creative Ltd | Information & communication | 2024 |
| Celey Homes Limited | Construction | 2017 |
| Celieplant UK Ltd | Wholesale & retail | 2021 |
| Centil Energy Limited | Financial services | 2025 |
| Centric Homes Ltd | Real estate | 2008 |
| Centric New Homes Limited | Construction | 2019 |
| CEO Agri-Tech Ltd | Agriculture & fishing | 2023 |
| Certaindate Property Management Limited | Households | 1994 |
| Cesa Transport Limited | Transport & logistics | 2023 |
| Cezar Ruxanda Ltd | Transport & logistics | 2018 |
| Cezar Soitu Trans Ltd | Transport & logistics | 2015 |
| Cezar's Recovery Ltd | Transport & logistics | 2023 |
| CG Occupational Health Ltd | Health & social care | 2021 |
| CGA Lighting Ltd | Professional & scientific | 2008 |
| CGO Construction Limited | Construction | 2017 |
| Chain Trailer Services Limited | Administrative & support | 2021 |
| Chameleogenics UK Ltd | Information & communication | 2015 |
| Champagne That Cares Limited | Wholesale & retail | 2021 |
| Champion Brands Limited | Financial services | 2025 |
| Champion Construction (East Anglia) Ltd | Administrative & support | 2024 |
| Channing Engineering Ltd | Professional & scientific | 2012 |
| Chapel Motor Repairs Limited | Wholesale & retail | 2013 |
| Chapelgate Homes and Renovations Ltd | Construction | 2024 |
| Chapmans Business Solutions Limited | Professional & scientific | 2014 |
| Chapmans Consultants Ltd | Professional & scientific | 2022 |
| Chapmans Holdings Ltd | Financial services | 2019 |
| Charles Edward Fernandez Limited | Extraterritorial | 2024 |
| Charles Fernandez Ltd | Extraterritorial | 2024 |
| Charlie Star Ltd | Wholesale & retail | 2013 |
| Charlton Refrigeration Services Ltd | Manufacturing | 2007 |
| Charterhouse Properties (Holbeach) Limited | Real estate | 1999 |
| Chas T Thorold Ltd | Agriculture & fishing | 2018 |
| Chase Alexander Land Limited | Extraterritorial | 2005 |
| Cheeky Quid Ltd | Wholesale & retail | 2012 |
| Cheer & Dance House Ltd | Arts & recreation | 2024 |
| Chemex Franchising Ltd | Professional & scientific | 2023 |
| Chemical Box Limited | Wholesale & retail | 2021 |
| Cheque Mate Bookkeeping Services Ltd | Administrative & support | 2013 |
| Cherry Blossom Retail Ltd | Wholesale & retail | 2023 |
| Cherry Farm Contracting Ltd | Agriculture & fishing | 2016 |
| Cherry Hill Tree Services Ltd | Administrative & support | 2026 |
| Cherry Trees (Gosberton) Management Company Limited | Households | 2025 |