| Busanga Safaris Ltd | Administrative & support | 2005 |
| Buserror Dynamics Limited | Information & communication | 2014 |
| Business DNA Limited | Professional & scientific | 2006 |
| Business Doulas Ltd | Professional & scientific | 2019 |
| Business Negotiation Academy Ltd | Professional & scientific | 2018 |
| Busy BEE Domestic & Commercial Cleaning Ltd | Administrative & support | 2019 |
| Busy Buttons Core | Education | 2018 |
| Busy Fingers Sewing Co Limited | Manufacturing | 2012 |
| BUY4U Commerce Ltd | Wholesale & retail | 2026 |
| Buyzoo World Ltd | Wholesale & retail | 2025 |
| Bvalco Ltd | Administrative & support | 2010 |
| Bvimp Ltd | Real estate | 2023 |
| Bwilliant Pub's Ltd | Hospitality | 2025 |
| Bxsd Holdings Limited | Financial services | 2025 |
| Byrne AML Technical Training (Batt) Ltd | Professional & scientific | 2017 |
| Byron Court (Windsor) Freehold Limited | Households | 2006 |
| C C Sales Service and Training Limited | Professional & scientific | 2024 |
| C G Stanbury Ltd | Other services | 2020 |
| Caarro Limited | Hospitality | 2016 |
| Cafe and Kebab Limited | Hospitality | 2024 |
| Cafgold Limited | Hospitality | 1986 |
| Calibso Commercial Limited | Real estate | 2024 |
| Calibso Holdings Limited | Financial services | 2021 |
| Caline Investments Limited | Real estate | 1964 |
| Callon UK Limited | Wholesale & retail | 2019 |
| Calmspace Investments Limited | Extraterritorial | 2011 |
| Calumfyfe Limited | Professional & scientific | 2022 |
| Camadd Ltd | Professional & scientific | 2017 |
| Camasu Ltd | Other services | 2019 |
| Camouflage Films Limited | Information & communication | 2013 |
| Camperdown House Limited | Households | 1974 |
| Camperdown HOUSE(17-24)RTM Company Limited | Households | 2009 |
| CAN Advertising (EOT) Limited | Financial services | 2025 |
| CAN Advertising Holdings Limited | Professional & scientific | 2016 |
| CAN Advertising Limited | Professional & scientific | 2010 |
| Canary Yacht Ltd | Hospitality | 2024 |
| Canberra Green (Charvil) Management Company Limited | Households | 2021 |
| Candoolite Limited | Professional & scientific | 2015 |
| Canopy Crew Events Limited | Administrative & support | 2023 |
| CAO Consultancy Limited | Professional & scientific | 2013 |
| Cape Verde Property Investments Ltd | Real estate | 2010 |
| Capethorn Limited | Real estate | 2024 |
| Capitol Associates Limited | Professional & scientific | 1998 |
| Capstar Group Limited | Financial services | 2015 |
| Capstar Services (UK) Limited | Administrative & support | 2012 |
| Capsule DC UK Limited | Information & communication | 2025 |
| Cara Consultancy Services Limited | Professional & scientific | 2024 |
| Carbon Community Trading Limited | Agriculture & fishing | 2020 |
| Carbon Copy Network | Professional & scientific | 2019 |
| Cardigan Educational Media Ltd | Education | 2024 |
| Cardinal Light Limited | Administrative & support | 2024 |
| Care Cartons Ltd | Wholesale & retail | 2020 |
| Care Computers & Services Limited | Information & communication | 1993 |
| Care EB Ltd | Administrative & support | 2022 |
| Care Free Flooring Ltd | Construction | 2024 |
| Caremont Ltd | Health & social care | 2023 |
| Cargocair Ltd | Transport & logistics | 2023 |
| Cariad Consultancy Limited | Professional & scientific | 2006 |
| Carleton Property Investments Limited | Real estate | 2024 |
| Carol White Education Ltd | Education | 2018 |
| Carpet & Window Cleaning Ltd | Administrative & support | 2019 |
| Carrollclean Ltd | Administrative & support | 2015 |
| Carrying a Dream Ltd | Extraterritorial | 2021 |
| Carson Consulting Engineers Limited | Professional & scientific | 2012 |
| Cartsdyke Services Ltd | Administrative & support | 2016 |
| Casam Projects Ltd | Administrative & support | 2025 |
| Casen Doors Ltd | Wholesale & retail | 2024 |
| Cassey Legal Limited | Professional & scientific | 2026 |
| Castata Limited | Professional & scientific | 1998 |
| Castle and Tyne Homes Ltd | Real estate | 2023 |
| Castle Apartments Ltd | Construction | 2018 |
| Castle Car Park Management Limited | Transport & logistics | 2006 |
| Castle Care Villages Limited | Extraterritorial | 2014 |
| Castle Forbes Collection Limited | Wholesale & retail | 1996 |
| Castle Group Management Ltd | Households | 2019 |
| Castle Hill (Maidenhead) Ltd | Real estate | 2022 |
| Castle Tyne Properties Ltd | Hospitality | 2023 |
| Castle View Retirement Village Ltd | Real estate | 2018 |
| Castle View RTM Company Limited | Households | 2009 |
| Castlebrooke Limited | Financial services | 2016 |
| Castlemead Court Management Company Limited | Households | 1986 |
| Castlemere (DK) Ltd | Real estate | 2023 |
| Castlemere (Embassy) Ltd | Real estate | 2024 |
| Castlemere (Hamilton) Ltd | Real estate | 2023 |
| Castlemere (London) Ltd | Real estate | 2023 |
| Castlemere Construction Ltd | Construction | 2020 |
| Castlemere Developments Limited | Financial services | 2017 |
| Castlemere DKR Ltd | Real estate | 2024 |
| Castlemere Estates Ltd | Real estate | 2025 |
| Castlemere Holdings Limited | Financial services | 2017 |
| Castlepoint Services Ltd | Health & social care | 2015 |
| Castles Services Limited | Construction | 2024 |
| Cavendish Grove (Raynes Park) Residents Management Company Limited | Households | 2024 |
| CB Air Limited | Transport & logistics | 2006 |
| CB Investments Hounslow Limited | Real estate | 2015 |
| CBS Energy Storage Assets UK Limited | Energy | 1989 |
| CBS Services Holdings Limited | Financial services | 2015 |
| CBS Solar Assets UK Limited | Administrative & support | 2020 |
| CBT Conversations Limited | Health & social care | 2019 |
| Cbworldsuppliers Ltd | Wholesale & retail | 2025 |