| Brookmans Building Services Limited | Construction | 2025 |
| Brookmans Developments Limited | Construction | 2017 |
| Brookmans Family Butchers Limited | Wholesale & retail | 2016 |
| Brookmans Park Private Security CIC | Administrative & support | 2024 |
| Brookmans Park Roads Ltd | Real estate | 2011 |
| Brookmans Property Holdings Limited | Financial services | 2021 |
| Brooks Brbs Ltd | Other services | 2019 |
| Brookshire Midland Limited | Real estate | 2000 |
| Brookshire Properties Limited | Real estate | 2008 |
| Brookstone Trade Ltd | Wholesale & retail | 2025 |
| Brookwood RTM Company Limited | Real estate | 2014 |
| Brothers L Construction & Building Limited | Construction | 2022 |
| Brunch & Brew (Richmond) Ltd | Hospitality | 2020 |
| BRY Automobile Ltd | Wholesale & retail | 2025 |
| Buff Bros Ltd | Administrative & support | 2025 |
| Build With Steel Ltd | Construction | 2026 |
| BUILD4EVER Ltd | Construction | 2017 |
| Buildwell Properties Ltd | Construction | 2023 |
| Bullitt Property Investments Ltd | Real estate | 2019 |
| Burton Waters (H L & R ) Limited | Professional & scientific | 1998 |
| Bush Wheeler Services Limited | Administrative & support | 2003 |
| Bushra Care Company Limited | Health & social care | 2024 |
| Business Force Limited | Wholesale & retail | 1985 |
| Business Networking Limited | Information & communication | 2010 |
| Business Networking LNE Ltd | Other services | 2015 |
| Business Smart International Ltd | Professional & scientific | 2006 |
| Busy Business Limited | Extraterritorial | 1995 |
| Butchers Block Ltd | Wholesale & retail | 2024 |
| Butlers Mead Developments Limited | Construction | 2002 |
| BW Consultants Limited | Construction | 1998 |
| Byrne Creative Limited | Arts & recreation | 2023 |
| C & a Engineering Services Ltd | Construction | 2019 |
| C & MG Pharma Consulting Limited | Professional & scientific | 2023 |
| C B Bespoke Ltd | Wholesale & retail | 2011 |
| C Beyond IT Limited | Information & communication | 2019 |
| C J Church Ltd | Construction | 2026 |
| C M B Builders LLP | | 2017 |
| C Ryan Hospitality Holdings Limited | Financial services | 2023 |
| C&I Cleaning Ltd | Administrative & support | 2024 |
| C&M Apartments Limited | Hospitality | 2016 |
| C&T Services Limited | Construction | 2017 |
| C.G.Ardagh Investments Ltd | Real estate | 2021 |
| C.J.Norman Limited | Professional & scientific | 1995 |
| C.P.S Chips Property Services Ltd | Construction | 2014 |
| CAB Filip Limited | Hospitality | 2025 |
| Cacula Limited | Administrative & support | 2016 |
| CAD Systems Limited | Extraterritorial | 1984 |
| Cadenza London Limited | Wholesale & retail | 2022 |
| Cadima Care & Cleaning Limited | Health & social care | 2013 |
| Cadisch Holdings Limited | Financial services | 2025 |
| Cadisch Precision Meshes Limited | Manufacturing | 1990 |
| Cadogan Security Services Ltd | Administrative & support | 2018 |
| Caerus Innovation Limited | Administrative & support | 2011 |
| Cairns (Tring Road) Developments Limited | Real estate | 2021 |
| Cake DOT World Ltd | Manufacturing | 2018 |
| Cake HUT Ltd | Hospitality | 2017 |
| CAL Haulage Ltd | Administrative & support | 2017 |
| Calibre Acquire Limited | Real estate | 2025 |
| Calibre Cottages Ltd | Real estate | 2023 |
| Calidra Installations Ltd | Construction | 2010 |
| Caljon Ltd | Professional & scientific | 2013 |
| Callcovered Limited | Information & communication | 2026 |
| Cambria Automobiles (Swindon) Limited | Wholesale & retail | 2004 |
| Cambria Automobiles Acquisitions Limited | Professional & scientific | 2006 |
| Cambria Automobiles Group Limited | Professional & scientific | 2006 |
| Cambria Investments Holdings Limited | Financial services | 2021 |
| Cambria Management Services Limited | Professional & scientific | 2006 |
| Cambria Private Capital Limited | Financial services | 2023 |
| Cambria Property Investments Limited | Real estate | 2006 |
| Cambria Vehicle Services Limited | Wholesale & retail | 2008 |
| Cambria Ventures Limited | Financial services | 2021 |
| Cambridge Image Technology Limited | Manufacturing | 1987 |
| Camera Bodies Limited | Extraterritorial | 2021 |
| Campbell Advisors Limited | Professional & scientific | 2020 |
| Camsi Ltd | Wholesale & retail | 2019 |
| Canford Law Ltd | Professional & scientific | 2016 |
| Cannonfire Battle Tours Limited | Administrative & support | 2009 |
| Canons Court RTM Company Ltd | Households | 2018 |
| Cansom Hunt Limited | Information & communication | 2022 |
| Caova Group Ltd | Transport & logistics | 2017 |
| Capital Connect (2009) Limited | Real estate | 2009 |
| Capital Drywall Limited | Administrative & support | 2007 |
| Capital Excelsior Limited | Real estate | 2012 |
| Capta FX Limited | Professional & scientific | 2016 |
| Car Accessory Motors (Potters Bar) Limited | Wholesale & retail | 1971 |
| Carbon Offsetting UK Limited | Wholesale & retail | 2022 |
| Care Angylion Ltd | Administrative & support | 2023 |
| Care Embassy Consultancy and Training Ltd | Administrative & support | 2017 |
| Care Logic Group UK Ltd | Administrative & support | 2025 |
| Care Sync Experts Limited | Administrative & support | 2024 |
| Care Sync Pro Ltd | Administrative & support | 2025 |
| Care With Hope Limited | Health & social care | 2026 |
| Careena Ltd | Administrative & support | 2025 |
| Carenest Wellbeing Services Ltd | Public administration | 2026 |
| Carevo Limited | Transport & logistics | 2017 |
| Carfs Construction Ltd | Construction | 2014 |
| Caribe Skin Limited | Wholesale & retail | 2022 |
| Carina Haslam Gallery Ltd | Wholesale & retail | 2019 |
| Caring World Healthcare Limited | Health & social care | 2022 |
| Carl Russell & Co Limited | Wholesale & retail | 2014 |