| Cabco AA Limited | Transport & logistics | 2025 |
| Cable & Civils Ltd | Construction | 2011 |
| Cactus Crew Ltd | Hospitality | 2021 |
| CAD Solutions PVT Ltd | Transport & logistics | 2014 |
| Cad-Make Limited | Professional & scientific | 2017 |
| Cadac Morris Ltd | Manufacturing | 2020 |
| Caddington Estates Limited | Real estate | 2026 |
| Caddington Holdings Ltd | Financial services | 2026 |
| Caddington Maintenance Ltd | Construction | 2024 |
| Caddington Motors Ltd | Wholesale & retail | 2020 |
| Caddington Properties Ltd | Real estate | 2022 |
| Cadi Serv Ltd | Wholesale & retail | 2021 |
| CAE Engineering Ltd | Manufacturing | 2019 |
| Caem Motor Trader Ltd | Wholesale & retail | 2021 |
| Caemac Investments Limited | Health & social care | 2010 |
| Caesar Communications Ltd | Information & communication | 2024 |
| Cafe 1 (UK) Ltd | Hospitality | 2009 |
| Cafe 1 Academy Ltd | Hospitality | 2023 |
| Cafe 1 Catering & Wholesale Ltd | Wholesale & retail | 2026 |
| Cafe 1 CC Ltd | Hospitality | 2026 |
| Cafe 1 Consulting Ltd | Hospitality | 2026 |
| Cafe 1 Futures Ltd | Wholesale & retail | 2025 |
| Cafe 7 & Pizzeria Ltd | Professional & scientific | 2017 |
| Cafe 71 Ltd | Hospitality | 2024 |
| Cafe Amoor Ltd | Hospitality | 2022 |
| Cafe BEN Limited | Hospitality | 2026 |
| Cafe Grill BBQ & Dessert Limited | Hospitality | 2026 |
| Cafe Grill Restaurant Ltd | Hospitality | 2024 |
| Cafe Grill ST Albans Ltd | Hospitality | 2023 |
| Cafe Italia (Luton) Ltd | Hospitality | 2017 |
| Cafe Luton Ltd | Hospitality | 2025 |
| Cafe Miraj Ltd | Hospitality | 2022 |
| CAFE1 SA Ltd | Hospitality | 2025 |
| CAFE169 Ltd | Hospitality | 2025 |
| Caffeine and Iron Ltd | Manufacturing | 2025 |
| CAG LAB Design Ltd | Professional & scientific | 2024 |
| Cainiao UK Supply Chain Limited | Transport & logistics | 2023 |
| Cairon Ltd | Construction | 2025 |
| Cake O'Licious Limited | Manufacturing | 2011 |
| Cakery in the Making Ltd | Manufacturing | 2025 |
| Cakes by Sobi Ltd | Wholesale & retail | 2020 |
| Cakes Royale Ltd | Hospitality | 2025 |
| Calai Ltd | Information & communication | 2026 |
| Calator Prin Lume Ltd | Water & waste | 2024 |
| Caldararu Victor Ltd | Construction | 2026 |
| Caldd Ltd | Other services | 2026 |
| California Crispy Chicken Ltd | Hospitality | 2025 |
| California Luton Ltd | Real estate | 2021 |
| Calldoc Ltd | Health & social care | 2025 |
| Callm Investments Ltd | Financial services | 2019 |
| Callum Security Solutions Ltd | Administrative & support | 2022 |
| Calmab Ltd | Wholesale & retail | 2018 |
| Calvary Care Support Services Ltd | Health & social care | 2025 |
| Calyem Legal Services Limited | Professional & scientific | 2017 |
| Cambrian Funding Limited | Financial services | 2014 |
| Cambridge Atlantic Limited | Real estate | 2023 |
| Cambridgeversity Limited | Education | 2024 |
| Camden ROW Ltd | Education | 2025 |
| Camel Ltd | Wholesale & retail | 2019 |
| Campaign for Real ALE Limited | Other services | 1976 |
| Campbell Glenorchy Consulting Limited | Professional & scientific | 2007 |
| Camping GAS Ltd | Information & communication | 2005 |
| Campusflow Ltd | Information & communication | 2026 |
| Camra Limited | Hospitality | 1987 |
| CAN DO People C.I.C. | Information & communication | 2024 |
| CAN Logic Ltd | Wholesale & retail | 2015 |
| Canadian Pacific (UK) Limited | Extraterritorial | 1915 |
| Canary Nails Spa Ltd | Other services | 2025 |
| Candy Castle Ltd | Wholesale & retail | 2023 |
| Candy Corner Limited | Real estate | 2016 |
| Candy N Choc Ltd | Wholesale & retail | 2024 |
| Canespa (UK) Limited | | 1976 |
| Cannon Group Ltd | Administrative & support | 2013 |
| Cannon Guards Security Ltd | Administrative & support | 2004 |
| Cannon Recruitment Ltd | Administrative & support | 2014 |
| Canny Electrical Ltd | Construction | 2025 |
| Canny Plastering Limited | Extraterritorial | 2016 |
| Canny Rentals Ltd | Real estate | 2024 |
| Canny Screeding Ltd | Construction | 2014 |
| Canopus Limited | Extraterritorial | 2013 |
| Canterbury Property Ltd | Households | 2023 |
| CAP Solar Management Ltd | Construction | 2024 |
| Capital Cent Limited | Transport & logistics | 2022 |
| Capital Executive Cars Ltd | Transport & logistics | 2025 |
| Capital Flow Enterprise Ltd | Wholesale & retail | 2026 |
| Capital Hill Estates Limited | Real estate | 2024 |
| Capital Home Improvements Ltd | Construction | 2026 |
| Capital HR Services Limited | Professional & scientific | 2020 |
| Capital Keystone Ltd | Professional & scientific | 2017 |
| Capital Management Systems Ltd | Financial services | 2024 |
| Capital Premier Roofing Ltd | Construction | 2025 |
| Capital Recruit Limited | Administrative & support | 2018 |
| Capital Roofing Care Ltd | Construction | 2025 |
| Capo Building Services Limited | Construction | 2018 |
| Capo Enterprise Limited | Wholesale & retail | 2023 |
| Caprecon International Development and Humanitarian Foundation | Education | 2019 |
| Capricorn Detergents Limited | Manufacturing | 2001 |
| Capron Cars Ltd | Wholesale & retail | 2019 |
| Capstone Management Consultants Limited | Professional & scientific | 2015 |
| Captain 804 Ltd | Hospitality | 2024 |