| Barclay Mews Freehold Company Limited | Households | 1997 |
| Barden Glazing Ltd | Construction | 2024 |
| Barker & Co. Installations Limited | Construction | 2016 |
| Barker Martial Arts Ltd | Arts & recreation | 2011 |
| Barking Marvellous Ltd | Other services | 2022 |
| Barnes Construction South East Limited | Administrative & support | 2004 |
| Barnes Contractors (South East) Limited | Construction | 2003 |
| Barnes Contractors (UK) LLP | | 2008 |
| Barnhams Ltd | Water & waste | 2019 |
| Barnhaus Homes Ltd | Real estate | 2018 |
| Barrett Bros,(Electrical)Limited | Construction | 1970 |
| Barrett's Limited | Professional & scientific | 1995 |
| Barry Wong Limited | Professional & scientific | 2024 |
| Bartlett Chiropractic Limited | Health & social care | 2002 |
| Baruch Services Ltd | Administrative & support | 2017 |
| Basil Property POT Limited | Real estate | 2023 |
| Bass PHD Limited | Construction | 2024 |
| Bastow Holdings Limited | Professional & scientific | 2017 |
| Battrick Consulting Limited | Financial services | 2024 |
| BAU Development Properties Limited | Construction | 2012 |
| Bauw Capital Ltd | Financial services | 2025 |
| Bauw Properties Ltd | Real estate | 2024 |
| Bauw Services Limited | Real estate | 2026 |
| Bay Electrical Ltd | Construction | 2024 |
| Bay Middleton Capital Ltd | Financial services | 2024 |
| Bayard Packaging Limited | Manufacturing | 1983 |
| Bayford New Horizons Limited | Health & social care | 2009 |
| Bayford New Horizons Trust Limited | Professional & scientific | 2023 |
| BB Topco Limited | Financial services | 2026 |
| BBA Digital Limited | Information & communication | 2012 |
| BBH Medical Solutions Ltd | Professional & scientific | 2023 |
| BBL Limited | Construction | 2018 |
| BBS London Ltd | Wholesale & retail | 2024 |
| Bcom Consulting Limited | Professional & scientific | 2019 |
| BDA Associates Limited | Professional & scientific | 2012 |
| Bdhsterling Group Limited | Financial services | 2019 |
| Bdhsterling Limited | Financial services | 2009 |
| BE Balanced Limited | Health & social care | 2004 |
| BE Clever With Your Cash Ltd | Administrative & support | 2015 |
| Beach Pubs UK Limited | Hospitality | 2025 |
| Beacon Landscapes Limited | Other services | 2019 |
| Beamhouse Enterprises Limited | Hospitality | 2019 |
| Beanies Colombian Coffee Roasters Ltd | Wholesale & retail | 2022 |
| Bear Island Ltd | Information & communication | 2024 |
| Bearstone Insights Limited | Professional & scientific | 2022 |
| Beaufort (AMY Road) Limited | Construction | 2025 |
| Beaufort (Printworks) Ltd | Construction | 2023 |
| Beaufort Construction Limited | Construction | 2015 |
| Beaufort Developments Limited | Construction | 2020 |
| Beaufort Homes Holdings Limited | Financial services | 2025 |
| Beaumont Park Investments Limited | Real estate | 2017 |
| Beaumont Place Residents Association Limited | Households | 1988 |
| Beauty FAN Ltd | Wholesale & retail | 2021 |
| Becton Court RTM Company Limited | Real estate | 2012 |
| Bedford Chambers Freehold Limited | Households | 2025 |
| BEE Kingdom Limited | Wholesale & retail | 2017 |
| Beech 62 Limited | Real estate | 2021 |
| Beech Seventeen Developments Ltd | Construction | 2016 |
| Beechwood Investments Limited | Financial services | 1983 |
| Beecom Security Solutions Limited | Administrative & support | 2023 |
| Bees Events Ltd | Wholesale & retail | 2022 |
| Bees Haulage & Hire Ltd | Transport & logistics | 2021 |
| Behind the Scenes (London) Limited | Arts & recreation | 2013 |
| Beinzeit Limited | Administrative & support | 2008 |
| Belgrave Fire Management Ltd | Public administration | 2024 |
| Belgravia Home Technology Ltd | Construction | 2015 |
| Belgravia Restorations Ltd. | Construction | 1991 |
| Belief to Change Ltd | Professional & scientific | 2011 |
| Belka Holdings Ltd | Financial services | 2023 |
| Bells Solutions Ltd | Professional & scientific | 2015 |
| Belmont Land Limited | Other services | 1985 |
| Belplace Seaford Limited | Households | 2023 |
| Bembo Ltd | Wholesale & retail | 2025 |
| BEN Bailey Construction Limited | Professional & scientific | 1958 |
| Benedict’S Building Services Ltd | Households | 2026 |
| Bennett Roofing Ltd | Construction | 2022 |
| Benridge Construction Limited | Construction | 2017 |
| Bens Butchery Limited | Hospitality | 2015 |
| Bentley Holmes Commercial Limited | Financial services | 2017 |
| Bentley Holmes Limited | Financial services | 2005 |
| Benton Arboriculture Limited | Other services | 2020 |
| Beresford Marney Ltd | Professional & scientific | 2012 |
| Berkshire Electrical Group Limited | Construction | 2024 |
| Bermuda Place RTM Company Limited | Extraterritorial | 2004 |
| Berqo Ltd | Wholesale & retail | 2026 |
| Berrylands Builders Ltd. | Construction | 2021 |
| Bertie 365 Ltd | Construction | 2025 |
| Bertieworks Limited | Information & communication | 2013 |
| Bess Home Renovations Ltd | Construction | 2023 |
| Best Choice Utilities Limited | Energy | 2020 |
| Best Choices Utility Limited | Transport & logistics | 2026 |
| Best Practice Artificial Intelligence Limited | Professional & scientific | 2018 |
| Best Properties Limited | Professional & scientific | 1983 |
| Beth Forrest Ltd | Health & social care | 2007 |
| Better Compliance Limited | Professional & scientific | 2009 |
| Better World Entertainment Limited | Professional & scientific | 2016 |
| Betula Holdings Ltd | Professional & scientific | 2025 |
| Bevan Park Residents Association Limited | Households | 1995 |
| Bevis Properties Limited | Real estate | 2017 |
| Bewt Limited | Professional & scientific | 2017 |