| Brownseabuild 5 Limited | Construction | 2017 |
| Brownseabuild 6 Limited | Construction | 2017 |
| Brownseabuild Limited | Construction | 2006 |
| Brownsters Financial Limited | Financial services | 2015 |
| Brushes and Beyond Ltd | Arts & recreation | 2025 |
| BTH Holdings Limited | Professional & scientific | 2007 |
| BU Fragrances Ltd | Wholesale & retail | 2026 |
| Buckbee Limited | Professional & scientific | 2013 |
| Buckbury Property Ltd | Construction | 2025 |
| Buckham Heath Ltd | Financial services | 2021 |
| Buckpace Limited | Arts & recreation | 1987 |
| Buggy Skies Ltd | Wholesale & retail | 2022 |
| Build and Kondition Ltd | Education | 2019 |
| Build Plus Maintenance Limited | Construction | 2024 |
| Build SG Limited | Construction | 2021 |
| Buildable Group Ltd | Information & communication | 2026 |
| Bulb Recruitment Limited | Administrative & support | 2016 |
| Bulb Recruitment Personnel Limited | Professional & scientific | 2025 |
| Bulic Capital Ltd | Real estate | 2023 |
| Bullrock Properties Limited | Professional & scientific | 1971 |
| Buona Mente Ltd | Wholesale & retail | 2025 |
| Burall Developments Limited | Real estate | 1986 |
| Bure Marine Equipment Ltd | Manufacturing | 2025 |
| Bure Marine Ltd | Manufacturing | 2025 |
| Burgess Boon Limited | Financial services | 2004 |
| Burgs HUT Ltd | Hospitality | 2016 |
| Burleys & Sons Ltd | Administrative & support | 2019 |
| Burleys Property and Management Services Ltd | Administrative & support | 2015 |
| Burns Advisory Limited | Professional & scientific | 2011 |
| Burrell Education Ltd | Education | 2019 |
| Burton House & Courtyard Management Company Limited | Households | 1997 |
| Burton Two Limited | Real estate | 2017 |
| Bury Estates Limited | Construction | 1929 |
| Bury Gate Ltd | Financial services | 2025 |
| Bury Manor School Trust Limited | Education | 1964 |
| BUS Stop Cafe 21 Ltd | Hospitality | 2024 |
| Bushnell Electrical Limited | Construction | 2015 |
| Business in Practice Ltd | Information & communication | 2025 |
| Business Information Technology Systems Limited | Information & communication | 2009 |
| Business Thinking Limited | Information & communication | 2003 |
| Busy Lizzie's Ltd | Education | 2007 |
| Butcher and Beast Ltd | Wholesale & retail | 2023 |
| Butler Group Properties Ltd | Real estate | 2023 |
| Butser Hill Lime Works Limited | Mining & quarrying | 1948 |
| Buzby & Blue Limited | Other services | 2004 |
| Buzby and Blue Academy Limited | Other services | 2014 |
| BW GAS Services Limited | Construction | 2022 |
| BX Plant Limited | Manufacturing | 1999 |
| Byrne Commercial Property Limited | Real estate | 2017 |
| Byrne Family Investments Limited | Financial services | 2017 |
| Byrne Property (Holdings) Ltd | Financial services | 2017 |
| Byrne Property Ltd | Real estate | 2016 |
| C & H Canterbury Ltd | Wholesale & retail | 2021 |
| C & J Marine Holdings (Southern) Limited | Other services | 2012 |
| C & J Marine Limited | Other services | 2003 |
| C England Ltd | Construction | 2017 |
| C J Plumbing & Developments Ltd | Construction | 2022 |
| C J Recruitment Limited | Administrative & support | 2010 |
| C Matthews Rugby Limited | Arts & recreation | 2023 |
| C Wood Consultancy Ltd | Professional & scientific | 2024 |
| C&H Horsham Ltd | Wholesale & retail | 2021 |
| C&H Tunbridge Wells Ltd | Wholesale & retail | 2021 |
| C&J Outdoors Limited | Extraterritorial | 2025 |
| C&J Property Lettings Sussex Ltd | Real estate | 2025 |
| C-Pek Solutions Ltd | Information & communication | 2026 |
| C. & B. Marine Limited | Administrative & support | 1984 |
| C. Bedford Properties Limited | Construction | 1980 |
| C. C. Marine Services Limited | Manufacturing | 1981 |
| C.& H.Fabrics Limited | Wholesale & retail | 1933 |
| C.B.C. Management Limited | Households | 1985 |
| C.D.Taverns Ltd | Hospitality | 2024 |
| C.E.H Consulting Limited | Professional & scientific | 2016 |
| C.J.D Development Consultants Limited | Real estate | 2024 |
| C.N.M Scaffolding Ltd | Construction | 2019 |
| C.P. Steelworks Limited | Manufacturing | 2002 |
| C.P.H. Limited | Financial services | 2003 |
| C20 Motor House Ltd | Transport & logistics | 2024 |
| C2G Holdings Ltd | Financial services | 2020 |
| C2G Properties Ltd | Real estate | 2020 |
| Cable-Links Ltd | Construction | 2023 |
| Cackler Harding Limited | Professional & scientific | 2011 |
| Cafe Grey Limited | Hospitality | 2025 |
| Cakeham Manor Estate Limited | Administrative & support | 1953 |
| Cakeham Stables Ltd | Agriculture & fishing | 2025 |
| Calibre Acoustics Limited | Administrative & support | 2008 |
| Callow & Griffiths Limited | Construction | 2015 |
| Calm Holdings Ltd | Administrative & support | 2021 |
| Calmstone IT Ltd. | Information & communication | 2011 |
| Calvey Marine Holdings Limited | Extraterritorial | 2007 |
| Calvey Marine Limited | Administrative & support | 1991 |
| Calwerx Ltd | Wholesale & retail | 2017 |
| Camberall Ltd | Information & communication | 2015 |
| Cambio Consulting Ltd | Professional & scientific | 2023 |
| Cambridge Management Support Ltd | Real estate | 2000 |
| Cammack Contractors Limited | Construction | 2006 |
| Camp Electrical Contractors Limited | Construction | 2019 |
| Campbell Court Worthing Limited | Households | 2006 |
| Campfire Stories Limited | Information & communication | 2011 |
| Cams Limited | Construction | 1929 |
| Cancanco. Ltd | Manufacturing | 2019 |