| Buildright Consultants Ltd | Professional & scientific | 2025 |
| Buildsmart Group Limited | Construction | 2017 |
| Bulk Property Investor Limited | Real estate | 2017 |
| Buoyant Care UK Limited | Health & social care | 2022 |
| Burgerbey Limited | Hospitality | 2019 |
| Bushpath Limited | Administrative & support | 1995 |
| Business and Beyond Consulting Ltd | Professional & scientific | 2025 |
| Business Clan Ltd | Professional & scientific | 2014 |
| Business Consultants (UK) Ltd | Professional & scientific | 2015 |
| Business Exhibition Events Limited | Professional & scientific | 2003 |
| Business Risks International Limited | Administrative & support | 1999 |
| Business Systems (North Wales) Limited | Wholesale & retail | 1991 |
| Busybrain Consulting Ltd | Information & communication | 2017 |
| Busybrains Healthcare Ltd | Real estate | 2004 |
| Butt & Co (UK) Limited | Wholesale & retail | 2016 |
| Buyitboxit Limited | Wholesale & retail | 2018 |
| BUZ Leasing Limited | Administrative & support | 2013 |
| BVA Couriers Ltd | Transport & logistics | 2025 |
| BVM Consultancy Services Limited | Information & communication | 2011 |
| Bvms Solutions Ltd | Wholesale & retail | 2017 |
| BW Facility Management Ltd | Households | 2019 |
| BW Handyman and Property Services Ltd | Construction | 2020 |
| BW Plastering Solutions Ltd | Construction | 2026 |
| BY Jasellarose Ltd | Arts & recreation | 2025 |
| BY Nature's Design Ltd | Wholesale & retail | 2026 |
| BY the Bridge Holdings Limited | Health & social care | 2006 |
| BY the Bridge Limited | Health & social care | 2000 |
| BY the Bridge Management Company Limited | Health & social care | 2013 |
| BY the Bridge North West Limited | Health & social care | 2005 |
| BYD (U.K.) Co., Ltd. | Wholesale & retail | 2013 |
| Bytespring Ltd | Information & communication | 2023 |
| C & a Commercial Cleaning Services Limited | Administrative & support | 2025 |
| C & D Disposal Ltd | Water & waste | 2024 |
| C C Builders UK & Development Ltd | Construction | 2012 |
| C E T Solutions Limited | Construction | 2011 |
| C Mallawaarachchi Limited | Health & social care | 2016 |
| C&B Painting&Deco Ltd | Construction | 2024 |
| C&I Management Ltd | Real estate | 2023 |
| C&T Bar Limited | Hospitality | 2024 |
| C&Z London Builders Ltd | Construction | 2021 |
| C.A.Carpentry Ltd | Manufacturing | 2019 |
| C.H. Maintenance Service Limited | Administrative & support | 2004 |
| C.R. Turner (Opticians) Limited | Health & social care | 1999 |
| C2 Solutions Limited | Information & communication | 1999 |
| CAB Cars Hire Ltd | Transport & logistics | 2021 |
| Cable and Devices UK Limited | Information & communication | 2014 |
| Cablesanddevices UK Limited | Wholesale & retail | 2025 |
| CAD T3CH Designs Ltd | Construction | 2017 |
| Cadbury Limited | Professional & scientific | 2008 |
| Cadbury Nominees Limited | Administrative & support | 1963 |
| Cadbury Schweppes Overseas Limited | Professional & scientific | 1899 |
| Cadbury Seven LLP | | 2011 |
| Cadbury South Africa (Holdings) | Professional & scientific | 2009 |
| Caerus House Ltd | Information & communication | 2025 |
| Caesar Grill Ltd | Hospitality | 2025 |
| Cafden Services Limited | Manufacturing | 2004 |
| Cafe Connections Limited | Wholesale & retail | 2002 |
| Cafe Ickenham Ltd | Hospitality | 2024 |
| Cafeteria Limited | Hospitality | 2020 |
| Cagliary Limited | Wholesale & retail | 2023 |
| Cahill Renovations Ltd | Real estate | 2025 |
| Cake in House Ltd | Manufacturing | 2024 |
| Caledonian Management Consultants Ltd | Professional & scientific | 2019 |
| Calibri Investments Limited | Construction | 2013 |
| Calin Metals Ltd | Administrative & support | 2020 |
| Call ME Care Ltd | Health & social care | 2023 |
| Callanan Plant Ltd | Administrative & support | 2020 |
| Callenyx Ltd | Information & communication | 2026 |
| Calori Ltd | Information & communication | 2025 |
| Calviro Services Ltd | Wholesale & retail | 2026 |
| Calviro Services Ltd Ltd | Wholesale & retail | 2026 |
| CAM Master Planning Ltd | Real estate | 2018 |
| CAM Renewable Investments LLP | | 2019 |
| Cambian Asperger Syndrome Services Limited | Other services | 2000 |
| Cambian Autism Services Limited | Education | 1997 |
| Cambian Childcare Limited | Health & social care | 2001 |
| Cambian Childcare Properties (SCT) Limited | Real estate | 2026 |
| Cambian Childcare Properties Limited | Administrative & support | 2004 |
| Cambian Education Services Limited | Financial services | 2005 |
| Cambian FS Limited | Professional & scientific | 2015 |
| Cambian Group Holdings Limited | Professional & scientific | 2014 |
| Cambian Group Limited | Professional & scientific | 2014 |
| Cambian Heritage I Limited | Financial services | 2004 |
| Cambian Heritage II Limited | Real estate | 1999 |
| Cambian Properties (U.K.) Limited | Financial services | 2005 |
| Cambian Signpost Limited | Health & social care | 2007 |
| Cambian Whinfell School Limited | Education | 2002 |
| Cambrian Care (Powys) Limited | Extraterritorial | 1999 |
| Camiers Group Limited | Water & waste | 2017 |
| Campillo Services Ltd | Administrative & support | 2016 |
| Candelabra Holding Group Ltd | Professional & scientific | 2024 |
| Candid Housing Solutions Ltd | Real estate | 2020 |
| Canine Curriculum Limited | Education | 2025 |
| Canon (UK) Limited | Administrative & support | 1976 |
| Canon Europe Limited | Manufacturing | 2000 |
| Canon Holdings (UK) Limited | Financial services | 1993 |
| Canvass Developers Ltd | Administrative & support | 2017 |
| Caoga Ltd | Construction | 2021 |
| CAP Capital Holdings Limited | Financial services | 2026 |
| Capable Roofing and Building Ltd | Construction | 2025 |