| Arun Property Professionals (Blocks) Limited | Administrative & support | 2026 |
| Arun Property Professionals Limited | Administrative & support | 2025 |
| Arun Pumpcrete Limited | Construction | 2017 |
| Arun Shipyard Properties Ltd | Real estate | 2021 |
| Arun SMS Ltd | Wholesale & retail | 2025 |
| Arun Timber Docks Ltd | Real estate | 2021 |
| Arun Valley Homes Limited | Construction | 2018 |
| Arun Windows Limited | Construction | 2007 |
| Arundel Property Holdings Ltd | Real estate | 2023 |
| Arundel Road Garage Limited | Wholesale & retail | 1975 |
| AS Agility Limited | Information & communication | 2016 |
| ASH Transport Freight Ltd | Transport & logistics | 2025 |
| Ashacre Homes Ltd | Real estate | 2025 |
| Ashbrook Interiors Limited | Construction | 2015 |
| Ashgate View Estate (Burwash) Management Company Limited | Real estate | 2025 |
| Ashgate View Flats (Burwash) Management Company Limited | Real estate | 2025 |
| Ashington Aviation Consultancy Ltd | Other services | 2006 |
| Ashlands RTM Company Limited | Households | 2019 |
| Ashmiles Residents Management Company Limited | Households | 2013 |
| Ashplats Management Company Ltd | Households | 2021 |
| ASK My Products Ltd | Information & communication | 2026 |
| Astec Europe Limited | Administrative & support | 1959 |
| Astute Investment Planning Limited | Extraterritorial | 2009 |
| Atex Equipment Ltd | Wholesale & retail | 1999 |
| Atlantis F & C Ltd | Hospitality | 2025 |
| Attle Costumiers Hire Ltd | Administrative & support | 2024 |
| Attle Costumiers Limited | Administrative & support | 2009 |
| Aubic Sales (Brighton) Limited | Manufacturing | 1975 |
| Audio Trader Ltd | Wholesale & retail | 2023 |
| Autark Limited | Extraterritorial | 2007 |
| Avatar Engineering Solutions Ltd | Professional & scientific | 2026 |
| Aviance Aviation Limited | Transport & logistics | 2025 |
| Avogo Ltd | Information & communication | 2021 |
| Avramoski Ltd | Wholesale & retail | 2021 |
| AW House of Aesthetics Ltd | Other services | 2025 |
| AW Stays Ltd | Real estate | 2023 |
| AXL Image Limited | Other services | 2018 |
| Axtell Automobile Associates Limited | Wholesale & retail | 1977 |
| Azur Auto Limited | Wholesale & retail | 2008 |
| Azur Developments Ltd | Real estate | 2014 |
| B & L Installations Sussex Limited | Construction | 2012 |
| B-Serve Ltd | Wholesale & retail | 2022 |
| B. and S. (Natural Stone) Limited | Construction | 1981 |
| B.B ENG Limited | Manufacturing | 2006 |
| B.B.FLOORING14 Ltd | Wholesale & retail | 2024 |
| Back Arun Fisheries Limited | Arts & recreation | 1998 |
| BACK2FITNESS Sussex Limited | Professional & scientific | 2024 |
| Badgers Close (Newhaven) Limited | Households | 2000 |
| Badlandz Limited | Arts & recreation | 2019 |
| Bah-Humbug Sweets Limited | Wholesale & retail | 2012 |
| Bailiffscourt Limited | Hospitality | 1993 |
| Baker Bots Ltd | Education | 2023 |
| Balloon Bar Ltd | Professional & scientific | 2025 |
| Balmar Properties Limited | Real estate | 2007 |
| Balpesh Ltd | Hospitality | 2026 |
| Baltic Wharf Studios Ltd | Hospitality | 2025 |
| Bammboo Ltd | Education | 2024 |
| Bancroft House Freehold Company Limited | Hospitality | 1999 |
| Baneros Consultancy Limited | Information & communication | 2024 |
| Bangers Natural Cafe Ltd | Wholesale & retail | 2024 |
| Banxlocal.Uk Limited | Financial services | 2023 |
| Barbon Property Ltd | Real estate | 2021 |
| Barbon Residential Ltd | Other services | 2021 |
| Barefoot Bridal Ltd | Wholesale & retail | 2018 |
| Bark&Bubbles Limited | Other services | 2022 |
| Barnham Station Taxis Ltd | Transport & logistics | 2023 |
| Barnhouse Close Limited | Households | 2009 |
| Barrington ORR Limited | Real estate | 2013 |
| Barry Wadsworth Limited | Wholesale & retail | 2004 |
| Barubu Limited | Wholesale & retail | 2020 |
| Based Projects Limited | Information & communication | 2022 |
| Basestone Ltd | Construction | 2020 |
| Bathrooms by Ceramica Ltd | Construction | 2025 |
| Bathyal Ltd | Mining & quarrying | 2022 |
| Batnote Ltd | Professional & scientific | 2026 |
| Baytree Land Limited | Real estate | 2011 |
| Bazonka Productions Ltd | Arts & recreation | 2015 |
| BB Luxe Finds Ltd | Wholesale & retail | 2026 |
| BBA Courier Systems Limited | Transport & logistics | 1996 |
| Bcmy Ltd | Water & waste | 2002 |
| BDS Office Limited | Wholesale & retail | 1993 |
| BE Sure Limited | Other services | 2011 |
| Beach Apartments Limited | Real estate | 2025 |
| Beach Court Residents' Association Limited | Households | 1961 |
| Beach Road DC Limited | Professional & scientific | 2024 |
| Beachtown Inns Ltd | Hospitality | 2020 |
| Beacon Cast Assets Ltd | Financial services | 2020 |
| Beaumont Gardens (Peacehaven) Residents Management Company Limited | Households | 2014 |
| Becket Investments Limited | Real estate | 2005 |
| Bedson Holdings Ltd | Real estate | 2019 |
| BEE Happy Hospitality Ltd | Administrative & support | 2026 |
| Beechbrook Park (Buxted) Management Co. Ltd | Households | 2011 |
| Beechfield Court (Management) Limited | Households | 1969 |
| Beechlands Ltd | Hospitality | 2023 |
| BEGIN2LIVE Ltd | Extraterritorial | 2025 |
| Belasis Ltd | Information & communication | 2020 |
| Belford Advisory Ltd | Information & communication | 2025 |
| Believe Fitness & Nutrition Limited | Education | 2022 |
| Belmaine Court(Worthing) RTM Company Limited | Administrative & support | 2019 |
| Belva Properties Limited | Real estate | 2017 |