| C.A. Wilson Design/Build Limited | Professional & scientific | 2001 |
| C.B. Burrows Limited | Wholesale & retail | 2006 |
| C.F.Consultancy (UK) Ltd | Other services | 2011 |
| C.M.C Carpentry Ltd | Manufacturing | 2022 |
| C.P. Installations (Southern) Limited | Construction | 1998 |
| CA 1 Ltd | Real estate | 2016 |
| Caddies Crawley Ltd | Arts & recreation | 2021 |
| Caddies Leisure Ltd | Arts & recreation | 2022 |
| Cadman Services Ltd | Professional & scientific | 2017 |
| Cafe Anglo Limited | Wholesale & retail | 2012 |
| Cafe DE Julia Limited | Hospitality | 2026 |
| Cafe Hind Foods (UK) Limited | Hospitality | 2017 |
| CAJ Consultants Ltd | Health & social care | 2024 |
| Cakes by Rehan Ltd | Manufacturing | 2026 |
| Calcam Limited | Construction | 2013 |
| Calder Grange (Dewsbury) Management Company Limited | Households | 2018 |
| Calion Investors Limited | Real estate | 2020 |
| Callum Stobart Building and Carpentry Ltd | Construction | 2026 |
| CAM Restaurant Limited | Hospitality | 2024 |
| Camadulo Limited | Financial services | 2024 |
| Cambridge DNA Technologies Limited | Health & social care | 2014 |
| Cambridge Smart Cars Ltd | Wholesale & retail | 2009 |
| Camellia Consulting Limited | Professional & scientific | 2022 |
| Camelot Property (Construction) Ltd | Wholesale & retail | 1998 |
| Campbell Creative Consultancy Ltd | Professional & scientific | 2022 |
| Camtech Limited | Information & communication | 2024 |
| Camtyres Limited | Wholesale & retail | 2012 |
| Camurria Limited | Hospitality | 2023 |
| Canaryford Limited | Health & social care | 1993 |
| Cancer Fitness Community Interest Company | Arts & recreation | 2024 |
| Canine Craft & Calm Limited | Information & communication | 2025 |
| Cannica Limited | Wholesale & retail | 2017 |
| Cannon Court Freehold Limited | Households | 2016 |
| Canvey Skip Hire & Recycling Limited | Transport & logistics | 2002 |
| Capdesigns Limited | Administrative & support | 2006 |
| Cape Designs Limited | Financial services | 2013 |
| Capital Leak Detection Specialists Ltd | Water & waste | 2021 |
| Capital Technical Services Group Limited | Water & waste | 2026 |
| Capsec Finance Ltd | Administrative & support | 2023 |
| Card Galacticos Limited | Other services | 2025 |
| Cardinia Web Consultants Ltd | Information & communication | 2010 |
| Care NOT Capital CIC | Arts & recreation | 2024 |
| Careersbyife Ltd | Professional & scientific | 2026 |
| Careerteam Limited | Real estate | 1997 |
| Carfolks Limited | Wholesale & retail | 2020 |
| Cariaco Ltd | Professional & scientific | 2026 |
| Caring Hands Essex Ltd | Health & social care | 2023 |
| Carla Bespoke Flowers Ltd | Wholesale & retail | 2025 |
| Carlsson Walker Ltd | Extraterritorial | 2007 |
| Carlton Films Ltd | Information & communication | 2022 |
| Carousel Day Nursery & Pre-School Ltd | Health & social care | 2019 |
| Carpin Properties Ltd | Real estate | 2007 |
| Carplife Products Ltd | Wholesale & retail | 2017 |
| Carrington Architectural Joiners Limited | Manufacturing | 1965 |
| Carshalton Beeches Leasehold Management Company Limited | Households | 2012 |
| Carthy Property Development Limited | Real estate | 2025 |
| CAS Capital 2010 Ltd | Extraterritorial | 2010 |
| Casa Outdoors Ltd | Wholesale & retail | 2025 |
| Case and Closed Limited | Wholesale & retail | 2018 |
| Cashbook Finance Limited | Financial services | 2017 |
| Casini Developments Limited | Construction | 2021 |
| Casini Holdings Limited | Financial services | 2021 |
| Casini New Homes Limited | Construction | 2021 |
| Casini Properties Limited | Real estate | 2024 |
| Casini Systems Limited | Administrative & support | 2002 |
| Caspian Bloom Holdings Ltd | Real estate | 2024 |
| Caspian Bloom Medical Ltd | Health & social care | 2024 |
| Castelnau Capital Partners Limited | Financial services | 2018 |
| Casting Bleu Ltd | Professional & scientific | 2019 |
| Castle Estate Agents (Essex) Limited | Real estate | 2013 |
| Castle House (High Wycombe) Management Company Limited | Households | 2018 |
| Castle Mews Management Company (Rayleigh) Limited | Households | 1998 |
| Castle Technology Limited | Information & communication | 1993 |
| Castlehythe Holdings Ltd | Professional & scientific | 2025 |
| Casualty & General (UK) Limited | Information & communication | 2016 |
| Caterbond Limited | Hospitality | 1982 |
| Catherington Park (Waterlooville) Management Company Limited | Households | 2018 |
| Catkins Child Care Sussex Limited | Health & social care | 2015 |
| Catsfield Court Maintenance Company Limited | Hospitality | 1966 |
| Caulfield Environmental Solutions Ltd | Construction | 2016 |
| Causal Software Limited | Information & communication | 2026 |
| Causeway Management Limited | Real estate | 2017 |
| Cavan House Capital Ltd | Financial services | 2024 |
| Cavemek Ltd | Professional & scientific | 2019 |
| CB Prime Property Services Ltd | Construction | 2025 |
| Cb-Computers Ltd | Wholesale & retail | 2023 |
| CBD (UK) Limited | Professional & scientific | 2013 |
| CC Speedshop Limited | Manufacturing | 2020 |
| CCM Properties Management Ltd | Real estate | 2018 |
| CCS Leisure Clean Limited | Administrative & support | 2020 |
| CCS Office Clean Ltd. | Administrative & support | 2023 |
| CDC Engineering and Fabrication Limited | Manufacturing | 2021 |
| Cdi-Fm Consult Ltd | Professional & scientific | 2023 |
| Cdls Property 2 Limited | Real estate | 2021 |
| Cdls Property A1 Limited | Real estate | 2017 |
| Cdls Property Opportunities Limited | Construction | 2018 |
| CDM Marketing Ltd | Information & communication | 2022 |
| CDM Solutions Limited | Professional & scientific | 2011 |
| Cecily's Limited | Wholesale & retail | 2019 |
| CED Services and Logistic Ltd | Construction | 2016 |