| BS Exchange Limited | Information & communication | 2020 |
| BSR Tech Solutions Limited | Information & communication | 2025 |
| BT Brickwork Ltd | Construction | 2019 |
| BTC (Sussex) Limited | Hospitality | 2018 |
| BTK Investments Limited | Real estate | 2022 |
| Btlt Consulting Limited | Construction | 2018 |
| Btnclaire & Co Limited | Professional & scientific | 2021 |
| BTR Property Ltd | Real estate | 2023 |
| Bubble Light Productions Limited | Information & communication | 2017 |
| Bubble Rentals Ltd | Real estate | 2023 |
| Buckingham Heights Residents Limited | Real estate | 2002 |
| BUD Flanagan Leukaemia Fund Limited | Other services | 2002 |
| Buddy Labs Ltd | Information & communication | 2026 |
| Build RAJ Ltd | Construction | 2019 |
| Build Viridis Ltd | Construction | 2022 |
| Builder's Beams Limited | Manufacturing | 2021 |
| Builders of Sussex Ltd | Construction | 2012 |
| Building Comfort Ltd | Manufacturing | 2022 |
| Building Plan Design Company Limited | Professional & scientific | 2016 |
| BUM BUM TAN Limited | Other services | 2025 |
| Bumblebee Bikes Ltd | Wholesale & retail | 2017 |
| BUN by Bunka Limited | Hospitality | 2024 |
| Burchells of Brighton Limited | Wholesale & retail | 2003 |
| Burchett Buildings Ltd | Extraterritorial | 2012 |
| Burgess Hill Family Funeral Services Limited | Other services | 2006 |
| Burlington Court (Worthing) Limited | Real estate | 1995 |
| Burning Sky Brewery Limited | Manufacturing | 2013 |
| Burrows Properties Limited | Real estate | 2013 |
| Burshi Ltd | Hospitality | 2021 |
| Burton & Brown Limited | Construction | 2008 |
| Busby Ventilation Limited | Construction | 2021 |
| Business and Human Rights Lawyers Association Limited | Other services | 2022 |
| Business Driven Limited | Professional & scientific | 2021 |
| Business Finance Advisors Limited | Administrative & support | 2021 |
| BUT First Ltd | Hospitality | 2016 |
| Butlers Estates Investments Ltd | Real estate | 2026 |
| Butlers Estates Limited | Real estate | 2020 |
| Butterflies Psychology Limited | Education | 2025 |
| Butters Plumbing & Heating Limited | Construction | 2015 |
| Buttys Bits Limited | Manufacturing | 2015 |
| Buxton Corner Residents Association Limited | Households | 1969 |
| BVH Universal Ltd | Professional & scientific | 2022 |
| BVM Properties Ltd | Real estate | 2017 |
| BY Brittany Ltd | Wholesale & retail | 2023 |
| BY GAS Heating Limited | Construction | 2016 |
| BY the Lake Lettings Ltd | Real estate | 2018 |
| BYB Property Ltd | Construction | 2014 |
| Byda TEC Limited | Other services | 2026 |
| Bykara Ltd | Wholesale & retail | 2025 |
| C & a Finishes Limited | Construction | 2014 |
| C & E Oriental Limited | Hospitality | 2020 |
| C & H Weston Limited | Wholesale & retail | 2001 |
| C & M Heating Ltd | Construction | 2014 |
| C & P Management ( Sussex) Ltd | Professional & scientific | 2011 |
| C & R Glass Polishing Ltd | Manufacturing | 2025 |
| C a Cornish & Associates Limited | Professional & scientific | 1990 |
| C Brewer & Sons Pension Scheme Trustees Ltd. | Financial services | 2019 |
| C Brewer & Sons Propco Limited | Real estate | 2020 |
| C Brewer & Sons Retirement Benefits Scheme Trustees Ltd | Financial services | 2019 |
| C E L Care Services Limited | Health & social care | 2016 |
| C G Jung Centre Limited | Extraterritorial | 2013 |
| C GUY Ltd | Health & social care | 2024 |
| C Levell Ltd | Construction | 2008 |
| C P Cassidy Limited | Health & social care | 2023 |
| C P Jones Building Ltd | Construction | 2025 |
| C S Bookkeeping Limited | Professional & scientific | 2019 |
| C S Roofing Contractors Limited | Construction | 2010 |
| C&O Healthcare Ltd | Financial services | 2025 |
| C&S Recycling Limited | Water & waste | 2024 |
| C-Thru Windows, Doors & Conservatories Ltd | Construction | 2021 |
| C. Carey Classic Mercedes Autos Ltd | Wholesale & retail | 2024 |
| C.H. Jointing Ltd | Construction | 2024 |
| C.P.Building Renovations Ltd | Construction | 2023 |
| C.S.Uncles Limited | Real estate | 1970 |
| CA Drawing Limited | Professional & scientific | 2015 |
| CA STUDIO22 Ltd | Professional & scientific | 2022 |
| Cable Group Ltd | Information & communication | 2012 |
| Cable Power Ltd | Construction | 2025 |
| Cable Rock Limited | Real estate | 2011 |
| Cadenza Consulting Services Ltd | Professional & scientific | 2025 |
| Cadenza Tuition Ltd | Education | 2024 |
| Cadogan Court (Pevensey Bay) Limited | Households | 1991 |
| Cafe 32 Limited | Hospitality | 2011 |
| Cafe Anka Limited | Hospitality | 2024 |
| Cafe Joon Ltd | Hospitality | 2024 |
| Caffe Italia (Eastbourne) Ltd | Hospitality | 2023 |
| Caffyns Wessex Limited | Extraterritorial | 1995 |
| Caigers Kitchen & Bathroom Installation Limited | Construction | 2019 |
| Caio Mastella Enke Ltd | Health & social care | 2021 |
| Caion Investments Limited | Real estate | 2018 |
| Caius House (Bexhill) Limited | Other services | 2005 |
| Caladine Limited | Professional & scientific | 2002 |
| Calamar Limited | Hospitality | 2014 |
| Calburn Services Limited | Manufacturing | 1999 |
| Calibrate Residents Association Limited | Households | 1992 |
| Calibro Ltd | Wholesale & retail | 2009 |
| Call-A-Cab Sussex Limited | Transport & logistics | 2013 |
| Calledout Sports Ltd | Arts & recreation | 2021 |
| Callenders Limited | Hospitality | 2011 |
| Callison Dent Limited | Health & social care | 2024 |