| Blank Canvas Web Designs Ltd | Information & communication | 2025 |
| Blended First AID Ltd | Extraterritorial | 2023 |
| Blind Fate Ltd | Information & communication | 2017 |
| Bloc Steel Ltd | Manufacturing | 2026 |
| Block Creations Ltd | Construction | 2003 |
| Blossom and BEE Floristry Ltd | Wholesale & retail | 2021 |
| Blue Rock Incentives Ltd | Administrative & support | 2018 |
| Bluebird Family Holdings | Other services | 2019 |
| Bluesix Design Ltd | Professional & scientific | 2011 |
| BML Property Investments Ltd | Real estate | 2018 |
| BN1 Investments Ltd | Real estate | 2019 |
| BN1 Madcal Ltd | Other services | 2025 |
| BN1 Security Ltd | Other services | 2012 |
| BN6 Craft Beer & TAP Ltd | Wholesale & retail | 2021 |
| Boardmasters Ironing Services Limited | Households | 2025 |
| Bohohuts Ltd | Manufacturing | 2025 |
| Bonnett Property Holdings Ltd | Real estate | 2026 |
| Bonvila Ltd | Wholesale & retail | 2010 |
| Boost Performance Limited | Administrative & support | 2017 |
| Boost Technology Group Limited | Professional & scientific | 2017 |
| Boyar Ltd | Wholesale & retail | 2014 |
| Bozyk Ltd | Other services | 2009 |
| Bradstock Building Ltd | Construction | 2013 |
| Brangwyn's Acre Residents Company Limited | Households | 2003 |
| Brian Davies Insurance Consultants Ltd | Financial services | 1999 |
| Bricks & Mortar Property Ltd | Real estate | 2019 |
| Bright Cause Consultancy Limited | Administrative & support | 2025 |
| Bright Film Weddings & Photography Limited | Information & communication | 2024 |
| Bright Teeth Ltd | Health & social care | 2014 |
| Bright World Education Limited | Education | 1999 |
| Bright World Guardianships Limited | Other services | 2002 |
| Bright World Limited | Professional & scientific | 2011 |
| Brighthelmstone Promotions Limited | Professional & scientific | 2012 |
| Brightiam Ltd | Professional & scientific | 2025 |
| Brighton and Hove Care at Home Limited | Health & social care | 2015 |
| Brighton and Hove Property Consortium Ltd | Administrative & support | 2017 |
| Brighton and Hove Property Ltd | Real estate | 2022 |
| Brighton Capital Holdings Ltd | Construction | 2023 |
| Brighton Couriers Limited | Transport & logistics | 2011 |
| Brighton Hub Limited | Households | 2013 |
| Brighton Motorcycles Ltd | Wholesale & retail | 2025 |
| Brighton Valeting Centre Ltd | Wholesale & retail | 2019 |
| Briony Lumb Associates Limited | Professional & scientific | 2014 |
| Brixter Construction Limited | Construction | 2017 |
| Brixter Probuild Ltd | Extraterritorial | 2025 |
| Brockbridge EST. Ltd | Real estate | 2021 |
| Brooklands Wedding Cars Sussex Limited | Administrative & support | 2019 |
| Brown & Sellwood Limited | Real estate | 2023 |
| Bruno Maia Ltd | Health & social care | 2012 |
| Brunswick Practice Limited | Health & social care | 2006 |
| BSF Ltd | Administrative & support | 2017 |
| Bullgate Properties Ltd | Real estate | 2026 |
| Bump Connect Limited | Other services | 2024 |
| Buon Appetito Sister Ltd | Hospitality | 2014 |
| Burgess Hill Glazing Limited | Construction | 2019 |
| Burns Holdings (UK) Limited | Professional & scientific | 2000 |
| Burrows 2 Investments Limited | Construction | 2022 |
| Burrows Investments Limited | Real estate | 2017 |
| Business Consulting International Limited | Professional & scientific | 2018 |
| Business Psychology in Practice Ltd | Health & social care | 2004 |
| Byboho Ltd | Wholesale & retail | 2022 |
| Bywater Hotelboat Cruises Limited | Transport & logistics | 2014 |
| C Chapman Consultancy Ltd | Professional & scientific | 2022 |
| C E Gill Limited | Education | 2023 |
| C J ARB Ltd | Agriculture & fishing | 2026 |
| C.F.I. Properties Limited | Administrative & support | 2001 |
| Cabins UK (Commercial) Ltd | Construction | 2012 |
| Cabins UK (Investments) Ltd | Real estate | 2021 |
| Cacaoamor Ltd | Wholesale & retail | 2025 |
| Cadman Investments Limited | Other services | 2015 |
| Cadman Properties Limited | Real estate | 2025 |
| Calmad Limited | Construction | 2026 |
| Camden 1919 Limited | Construction | 2020 |
| Camilla Treharne Limited | Professional & scientific | 2019 |
| Campion Gill Ltd | Real estate | 2021 |
| Capital Resourcing Limited | Other services | 2013 |
| Carbuddy Limited | Wholesale & retail | 2010 |
| Carmi Searle Associates Ltd | Professional & scientific | 2010 |
| Carod Developments Limited | Construction | 2023 |
| Carod Investments Limited | Other services | 2020 |
| Carod Properties (BG) Limited | Construction | 2023 |
| Carter-Olivier Engineering Ltd | Construction | 2018 |
| Cash Eagle Limited | Professional & scientific | 2023 |
| Cash Holdings Limited | Real estate | 2003 |
| Casone Partners Limited | Real estate | 1999 |
| Cat Waage Accounting Ltd | Professional & scientific | 2021 |
| Catherine Tong Consulting Limited | Professional & scientific | 2019 |
| Catherine Whitby Architects Limited | Professional & scientific | 2021 |
| CBA Holdings Ltd | Financial services | 2016 |
| Cecily Investments | Other services | 2017 |
| Cedar Green Projects Ltd | Manufacturing | 2010 |
| Ceegee Consultancy Limited | Professional & scientific | 2024 |
| Cenes Creative Ltd | Information & communication | 2022 |
| Certify Training Qualifications Ltd | Education | 2020 |
| CG Electrical South Limited | Construction | 2014 |
| Chad Electrical Ltd | Construction | 2023 |
| Chalk on the South Downs CIC | Education | 2025 |
| Chalkwell Group Limited | Financial services | 2026 |
| Charles William Developments Ltd | Real estate | 2020 |
| Chatterbox Sussex Speech and Language Therapy Ltd | Health & social care | 2017 |