| Brown Bear Training Ltd | Professional & scientific | 2025 |
| Brownhill Farm Studios Limited | Manufacturing | 1996 |
| Brownlow Holdings (Worthing) Limited | Real estate | 2019 |
| Browns Natural Pet Company Limited | Wholesale & retail | 2015 |
| Brownstone Properties Ltd | Real estate | 2017 |
| Brunch Shack Limited | Hospitality | 2025 |
| Brunswick Developments (Queens Road) Limited | Real estate | 2001 |
| Brutal Rigg Ltd | Arts & recreation | 2015 |
| Brutin Properties Limited | Professional & scientific | 2016 |
| Brutinellpres Limited | Real estate | 2014 |
| Bruwer Builds Ltd | Construction | 2024 |
| Bryant Appliance Repairs Ltd | Other services | 2017 |
| Brzn Ltd | Manufacturing | 2019 |
| BSS Cash and Carry Ltd | Wholesale & retail | 2025 |
| BSS Retailer Limited | Wholesale & retail | 2025 |
| BSY Consulting Ltd | Professional & scientific | 2026 |
| Btbsportstrading Limited | Information & communication | 2025 |
| Btlp Limited | Households | 2018 |
| BTR Brakes (Sussex) Limited | Wholesale & retail | 1990 |
| Buckingham Property Group Ltd | Real estate | 2022 |
| Buckland Consulting Limited | Professional & scientific | 2007 |
| Buckswood Ltd | Other services | 2020 |
| Buddson Ltd | Wholesale & retail | 2019 |
| Buds 'N' Blooms (Sussex) Limited | Wholesale & retail | 2005 |
| Bugibel Holdings Limited | Administrative & support | 2017 |
| Build and Co Group Ltd | Construction | 2026 |
| Build Friendly UK Limited | Wholesale & retail | 2025 |
| Building and Estate Services Limited | Construction | 2021 |
| Building Dream Home Limited | Construction | 2026 |
| Building Futures Holdings Ltd | Real estate | 2020 |
| Building Safety Compliance Ltd | Professional & scientific | 2025 |
| Buildserve Ltd | Construction | 2015 |
| Built Environment Media Limited | Information & communication | 2002 |
| Bun'Up Burgers Ltd | Hospitality | 2025 |
| Bungalow Town Productions Limited | Information & communication | 2004 |
| Bungard Technologies Ltd | Professional & scientific | 2012 |
| Bungaroosh Design Limited | Arts & recreation | 2015 |
| Bunting Consulting Ltd | Professional & scientific | 2023 |
| Burchett Construction and Project Management Ltd | Construction | 2023 |
| Burger MEE Limited | Hospitality | 2016 |
| Burgess Flooring & Blinds Limited | Wholesale & retail | 2013 |
| Burgess Flooring Blinds & More Ltd | Wholesale & retail | 2020 |
| Burlington Street Consultants Ltd | Professional & scientific | 2020 |
| Burnt Lemon Ltd | Financial services | 2024 |
| Burrell Buildings (Chartwell) Limited | Other services | 1988 |
| Burtech (Hants) Limited | Administrative & support | 2013 |
| Burton Electrical & Renewables Ltd | Construction | 2014 |
| Busby's Bakery School Limited | Education | 2019 |
| Bush Family Investments Limited | Real estate | 2019 |
| Business Accounting & Consultancy Limited | Professional & scientific | 1998 |
| Business Data Supplies Limited | Extraterritorial | 1980 |
| Business Development Group Limited | Professional & scientific | 2021 |
| Business Go Digital Ltd | Administrative & support | 2016 |
| Business Safety Advisory Service Ltd | Professional & scientific | 2015 |
| Business Solutions (Sussex) Ltd | Information & communication | 2025 |
| Business Travel Consultancy Global Limited | Professional & scientific | 2025 |
| Busylizzy Reigate & Horley Limited | Other services | 2017 |
| Butleriq Ltd | Information & communication | 2025 |
| Butnic Limited | Information & communication | 2007 |
| Buy Nice Things Ltd. | Wholesale & retail | 2020 |
| BVA Distribution Ltd | Wholesale & retail | 2023 |
| BVP Carpentry Ltd | Construction | 2023 |
| BW Consulting Engineers Limited | Professional & scientific | 2003 |
| BY the Sea Limited | Manufacturing | 1996 |
| Bygone Treasures Ltd | Wholesale & retail | 2022 |
| Byrne & Sprich Ltd | Administrative & support | 2021 |
| C & C Electrical Services Limited | Construction | 2007 |
| C & E Tools Limited | Wholesale & retail | 2014 |
| C & G Property Rentals Limited | Real estate | 2024 |
| C & J Cinema Ltd | Information & communication | 2026 |
| C & K Electrical Sussex Ltd | Construction | 2014 |
| C & M Brighton LLP | | 2022 |
| C & M Smith and SON Limited | Wholesale & retail | 2002 |
| C and a Troullos Properties Limited | Real estate | 2022 |
| C B Training Club Chichester Limited | Health & social care | 2025 |
| C B Training Club Holding Ltd | Other services | 2026 |
| C B Training Club Ltd | Health & social care | 2024 |
| C B Training Club Ockley Ltd | Health & social care | 2026 |
| C D Engineering Contractors Ltd | Professional & scientific | 2024 |
| C G Electrical Services Limited | Construction | 2002 |
| C H Investment Company Limited | Households | 1986 |
| C House Worthing Limited | Hospitality | 2013 |
| C R Plumbing & Heating Services (South) Ltd | Construction | 2018 |
| C R Poole Engineering Ltd | Manufacturing | 2016 |
| C&A Build Ltd | Construction | 2025 |
| C-Gas Services Ltd | Construction | 2021 |
| C. J. Hampshire Limited | Wholesale & retail | 2003 |
| C. M. Dodd Limited | Wholesale & retail | 2016 |
| C.J.S. Landscapes Ltd | Administrative & support | 2012 |
| C.W. Collier & Sons (1935) Limited | Wholesale & retail | 1980 |
| C2 Consulting (Oxford) Limited | Professional & scientific | 2020 |
| Cacodyl Limited | Real estate | 2025 |
| CAD Dynamics Ltd | Professional & scientific | 2024 |
| Cadexra Holdings Ltd | Financial services | 2024 |
| Cadogan Court Residents Association Limited | Households | 1967 |
| Cahill Jones Ltd | Information & communication | 2005 |
| CAJ Invest Ltd | Real estate | 2023 |
| Calahas Properties Limited | Real estate | 2003 |
| Calaris Ltd | Hospitality | 2025 |
| Calder Financial Solutions Ltd | Financial services | 2022 |