| Bridger Management Consulting Limited | Professional & scientific | 2016 |
| Bright Girl Songs Limited | Information & communication | 2004 |
| Bright Shots Limited | Information & communication | 2012 |
| Bright Space Global Ltd | Real estate | 2020 |
| Brightbridge Technologies Ltd | Information & communication | 2026 |
| Brightcircle Finance Limited | Information & communication | 2025 |
| Brightenco Ltd | Construction | 2025 |
| Brighton & Hove Estates Conservation Trust | Administrative & support | 2005 |
| Brilliant Businesses Limited | Professional & scientific | 2019 |
| Brim Chargers Limited | Manufacturing | 2020 |
| Brindle Construction Services Ltd | Construction | 2025 |
| Bring IT ALL Back Limited | Information & communication | 2022 |
| Brink Gallery Limited | Wholesale & retail | 2024 |
| Britain-Nepal Medical Trust(The) | Health & social care | 1967 |
| Britannic Trade Frames Limited | Wholesale & retail | 2010 |
| British Harlequin PLC | Construction | 1979 |
| Britt Construction Ltd | Water & waste | 2017 |
| Brittany Inns Limited | Hospitality | 1986 |
| Brittens Music (New HAW) Limited | Wholesale & retail | 2011 |
| Brittens Music (Tunbridge Wells) Limited | Wholesale & retail | 2008 |
| Brittens Music Limited | Financial services | 2008 |
| Brittens Music School Limited | Information & communication | 1998 |
| Brixton Developments Limited | Real estate | 2014 |
| Broadcroft (357) Management Company Limited | Real estate | 2019 |
| Broadfeed Limited | Administrative & support | 1984 |
| Broadlands Commercial Property Agents (TW) Limited | Real estate | 2015 |
| Broadmead Gardening Service Ltd. | Other services | 2016 |
| Broadwater Court Management Company Limited | Households | 1989 |
| Broadwater House (Freehold) Limited | Real estate | 2023 |
| Broadwater Investments Limited | Real estate | 1981 |
| Broadwater Pharma Limited | Wholesale & retail | 2026 |
| Broadwater Sussex LLP | | 2024 |
| Broken Mentality Ltd | Wholesale & retail | 2024 |
| Bromil Carpentry Limited | Construction | 2006 |
| Brook Manor Management Limited | Households | 1997 |
| Brookhurst Freehold Limited | Real estate | 2015 |
| Brooklands (Crowborough) Management Co. Ltd. | Households | 2007 |
| Brookson (5881G) Limited | Professional & scientific | 2010 |
| Broom Davey Ltd | Professional & scientific | 2017 |
| Broom Park Residents Association Limited | Households | 2007 |
| Broomfield Developments Ltd | Real estate | 2009 |
| Bross Print & Design Ltd | Manufacturing | 2010 |
| Browne Automotive Ltd | Wholesale & retail | 2023 |
| Brpm Engineering Ltd | Professional & scientific | 2020 |
| BRS Developments Ltd | Construction | 2021 |
| Bruce Manor Close Limited | Households | 2023 |
| Bruno Massey Associates LLP | | 2025 |
| Brunswick Place (Kings Hill) Management Company Limited | Households | 2002 |
| Brunton Properties Limited | Real estate | 2010 |
| Brushed Type Ltd | Information & communication | 2019 |
| Brushfire Design Ltd | Information & communication | 2005 |
| Bryant Artists Ltd | Administrative & support | 2006 |
| Bryant Style Ltd | Professional & scientific | 2010 |
| Bryher Solutions Limited | Information & communication | 2010 |
| Bryn Walden-Jones Creative Ltd | Professional & scientific | 2023 |
| BS21 CUT Limited | Other services | 2024 |
| BSR Bespoke LLP | | 2012 |
| Bstriven Limited | Hospitality | 2026 |
| Bsure Holdings Ltd | Financial services | 2024 |
| Bsure Plumbing Limited | Construction | 2013 |
| Bsure Small Works Ltd | Construction | 2024 |
| Btdreams Limited | Hospitality | 2021 |
| BTJL2 Limited | Construction | 2005 |
| BTM Southern Limited | Construction | 2019 |
| Bubba & ME Limited | Wholesale & retail | 2021 |
| Bubble Rocket Limited | Information & communication | 2021 |
| Buca Kennedy Ltd | Real estate | 2026 |
| Buchmann Ventures Ltd | Financial services | 2023 |
| Buck Films Limited | Information & communication | 2014 |
| Buckforde Ltd | Professional & scientific | 2022 |
| Bucks Phys Limited | Health & social care | 2003 |
| Buddi Bench Community Ltd | Health & social care | 2025 |
| Buddi Bench Limited | Health & social care | 2022 |
| Buddi Creatives Community Interest Company | Health & social care | 2025 |
| Bugatti Cars Limited | Professional & scientific | 1994 |
| Build Better Brands Ltd | Professional & scientific | 2012 |
| Build My Place Ltd | Manufacturing | 2019 |
| Building 15 Management Company Limited | Households | 2001 |
| Building Equipment Supplies Limited | Wholesale & retail | 2000 |
| Built by Dads Ltd | Other services | 2026 |
| Bullinger Holdings Limited | Other services | 2018 |
| Bullinger Wealth Limited | Financial services | 2018 |
| Bulls Hollow Consultancy Ltd | Professional & scientific | 2026 |
| Bungehurst Farms Ltd | Agriculture & fishing | 1997 |
| Burgess Management Consultants Limited | Professional & scientific | 2003 |
| Burke Enterprises (UK) Limited | Real estate | 1987 |
| Burke Enterprises Holdings LLP | | 2011 |
| Burke Enterprises LLP | | 2015 |
| Burkinshaw Management Limited | Real estate | 2007 |
| Burnhill Kitchens Contracting Ltd | Manufacturing | 2026 |
| Burns Property Company Limited | Real estate | 2015 |
| Burren Dance Ltd | Education | 2013 |
| Burtons Solicitors Limited | Professional & scientific | 2014 |
| Busi-Jacobsohn Wine Estate Limited | Extraterritorial | 2017 |
| Business Evolved Limited | Information & communication | 2026 |
| Buss Enterprises Ltd | Professional & scientific | 2024 |
| Buss Murton Law (South East) Limited | Professional & scientific | 2022 |
| Buss Murton Law LLP | | 2009 |
| Buss Murton Limited | Professional & scientific | 2009 |
| Butler Investment Ventures Limited | Real estate | 2024 |