| C1 Racing Limited | Arts & recreation | 2020 |
| C21 Scaffolding Limited | Construction | 2020 |
| C2P2 Ltd | Information & communication | 2022 |
| C3 Systems Consulting Ltd | Other services | 2009 |
| Cable Processing UK Ltd | Water & waste | 2025 |
| Cable Wharf Limited | Households | 2019 |
| Cabletech Computing Limited | Information & communication | 1998 |
| Caboodle Business Support Ltd | Professional & scientific | 2018 |
| Cactus Industries Ltd | Wholesale & retail | 2024 |
| CAD Premium Ltd | Professional & scientific | 2020 |
| Cadden Investments Limited | Real estate | 2023 |
| Caducifer Medical Services Limited | Health & social care | 2005 |
| Cadvise Ltd | Professional & scientific | 2025 |
| Cafeteq Ltd | Wholesale & retail | 2022 |
| Cain Developments Ltd | Real estate | 2024 |
| Calayo Company UK Ltd | Wholesale & retail | 2026 |
| Calc Accounting Limited | Professional & scientific | 2025 |
| Calcote Commercial LLP | | 2025 |
| Call Centre Planning Ltd | Professional & scientific | 2010 |
| Callaway Gardens (Facilities Management) Limited | Households | 2020 |
| Callen-Lenz Associates Limited | Professional & scientific | 2007 |
| Callum Hoblyn Ltd | Professional & scientific | 2021 |
| Calpe Port Properties Limited | Professional & scientific | 2011 |
| Camas Wine Limited | Wholesale & retail | 2024 |
| Cambiata Ltd | Arts & recreation | 2024 |
| Cambridge Heart Clinic Limited | Health & social care | 2025 |
| Cambridge Reagents Ltd | Wholesale & retail | 2016 |
| Cambridge Road Dunton Management Company Ltd | Households | 2023 |
| Came Farm Limited | Agriculture & fishing | 1960 |
| Camelot Care Homes Limited | Health & social care | 2002 |
| Camelot Commercial Services Ltd. | Real estate | 2021 |
| Camelot Property 1 Ltd. | Real estate | 2022 |
| Camer Holdings Limited | Financial services | 2020 |
| Camer Holdings Properties Ltd | Real estate | 2023 |
| Cameron House RTM Company Limited | Households | 2012 |
| Cameron Property Concern Ltd | Real estate | 2024 |
| Camicoma Ltd | Wholesale & retail | 2015 |
| Camp Bestival Limited | Arts & recreation | 2007 |
| Camp Crusoe Ltd. | Education | 2017 |
| Camperdown Limited | Administrative & support | 2016 |
| Canal Walk (Chichester) Management Company Limited | Households | 2013 |
| Canarywood Consulting Limited | Professional & scientific | 2022 |
| Candy Sunshine & Rainbows Ltd | Wholesale & retail | 2024 |
| Cannell Homes Ltd | Construction | 2019 |
| Cannon Asset Protection Limited | Administrative & support | 2013 |
| Canny Comms Ltd | Professional & scientific | 2019 |
| Canopy Safety Ltd | Professional & scientific | 2017 |
| Cantalla Ltd | Real estate | 2020 |
| Canterbury Park Residents Management Company Limited | Households | 2020 |
| Canvas Property Ltd | Real estate | 2024 |
| Canzona Ltd | Arts & recreation | 2005 |
| CAP Estates & Structures Limited | Real estate | 2023 |
| Capital and Professional Consulting Ltd | Professional & scientific | 2017 |
| Capital Order Limited | Financial services | 2019 |
| Capital SE Limited | Education | 2003 |
| Capstone Oaks Management Company Limited | Households | 2025 |
| Capstone Property Holdings Ltd | Real estate | 2026 |
| Captier Limited | Information & communication | 2025 |
| Captiosus Consulting Limited | Professional & scientific | 2018 |
| Cara Glass Limited | Construction | 2004 |
| Caravandays Ltd | Manufacturing | 2024 |
| Carbon Offset Recycling Limited | Wholesale & retail | 2024 |
| Carbon Order Investments NO 1 Limited | Financial services | 2012 |
| Carbon Order Ltd | Financial services | 2011 |
| Carbotech Ltd | Professional & scientific | 2018 |
| Carbrosah Ltd | Manufacturing | 1994 |
| Cardean Bell Limited | Financial services | 2016 |
| Cardiff Bling Limited | Administrative & support | 2020 |
| Cardington (Bedford) Management Company Limited | Households | 2019 |
| Care Deluxe Limited | Administrative & support | 2018 |
| Care NET UK 2003 Limited | Health & social care | 2003 |
| Care Safe Training and Consultancy Ltd | Health & social care | 2024 |
| Care Worker Register Ltd | Information & communication | 2025 |
| Carematch Limited | Other services | 2015 |
| Caresource 24/7 Ltd | Administrative & support | 2024 |
| Caring Support Services Limited | Health & social care | 2025 |
| Carl Robinson Consulting Limited | Information & communication | 2021 |
| Carlingford Court (Bognor Regis) Right to Manage Company Limited | Real estate | 2009 |
| Carlton Avenue (Block F) Management Company Limited | Households | 1991 |
| Carmel Meadows (Wallingford) Management Company Limited | Households | 2019 |
| Carnegie Capital Limited | Real estate | 2019 |
| Carnegie Capital Partners Limited | Professional & scientific | 2009 |
| Carnegie Management LLP | | 2009 |
| Carnegie Property Development Ltd | Construction | 2022 |
| Carnegie Property Partners Ltd | Construction | 2023 |
| Carnegie Real Estate Ltd | Construction | 2022 |
| Carnoustie Real Estate Services Ltd | Real estate | 2024 |
| Carpe Diem Catering Limited | Hospitality | 2019 |
| Carpet Corner (Salisbury) Ltd | Wholesale & retail | 2015 |
| Carr Design Studio Limited | Information & communication | 2003 |
| Cars 4 UK Ltd | Wholesale & retail | 2021 |
| Carsick Ltd | Arts & recreation | 2026 |
| Carter Consulting Group Ltd | Professional & scientific | 2021 |
| Carter MAY Limited | Real estate | 2012 |
| Carters Property and Garden Maintenance Ltd | Construction | 2025 |
| Carting House Close Management Limited | Real estate | 2017 |
| Carton Handling Solutions Limited | Manufacturing | 2012 |
| Cartona Park Estates Ltd. | Real estate | 2011 |
| Caruana Ltd | Financial services | 2019 |
| Cashed Ltd | Information & communication | 2026 |