| Balaji Maruti Ltd | Real estate | 2025 |
| Balanced Consulting Ltd | Professional & scientific | 2023 |
| Baldwin Place Residents Company Limited | Households | 2001 |
| Baldwin Tanner Ltd | Health & social care | 2022 |
| Balla Homes Ltd | Real estate | 2016 |
| BAM Transport Limited | Transport & logistics | 2013 |
| Bamba Online Store Ltd | Wholesale & retail | 2020 |
| Bamboo Vera Ltd | Professional & scientific | 2019 |
| Bamtex Limited | Wholesale & retail | 2023 |
| Bananahedgehog Productions Ltd | Information & communication | 2022 |
| Banbury Alton Limited | Professional & scientific | 1950 |
| Bancho Tech Ltd | Wholesale & retail | 2023 |
| Bandgi Technologies Ltd | Information & communication | 2010 |
| Banyan Tree Housing Limited | Real estate | 2022 |
| Barbara Evetts Limited | Health & social care | 2023 |
| Barbarella Property Investments Limited | Financial services | 2003 |
| Barbizon Europe Limited | Professional & scientific | 2002 |
| Barbon Advisors Operations Limited | Financial services | 2021 |
| Bare Minimum Botanics Ltd | Wholesale & retail | 2024 |
| Barefoot Ventures Ltd | Information & communication | 2019 |
| Barfly Consulting Limited | Professional & scientific | 2014 |
| Bargain Corner 786 Ltd | Wholesale & retail | 2020 |
| Bargate Drinks Limited | Wholesale & retail | 2012 |
| Baristars Ltd | Hospitality | 2023 |
| Barker Stone Ltd | Real estate | 2015 |
| Barker Stone Removals Limited | Transport & logistics | 2018 |
| Barkshire Dogs Ltd | Other services | 2023 |
| Barlow Handling Limited | Manufacturing | 2012 |
| Barloworld Equipment UK Limited | Wholesale & retail | 1994 |
| Barloworld Holdings Limited | Professional & scientific | 1984 |
| Barloworld Mongolia Limited | Financial services | 2019 |
| Barloworld UK Limited | Professional & scientific | 1914 |
| Barloworld UK Nominees Limited | Financial services | 1974 |
| Barn Built Fitness Limited | Arts & recreation | 2021 |
| Barnes Mayer Limited | Professional & scientific | 2003 |
| Barnes Pickle Limited | Information & communication | 2025 |
| Baron Consulting Management Ltd | Information & communication | 2017 |
| Barr & Beyene Ltd | Real estate | 2025 |
| Barrow Consultancy Services Limited | Professional & scientific | 2022 |
| Barry Symons Autos Limited | Wholesale & retail | 2020 |
| Barsham Consulting Limited | Real estate | 2017 |
| Barts Barbers Ltd | Other services | 2022 |
| Barwick Property Limited | Real estate | 2017 |
| BAS Consultants Limited | Information & communication | 2017 |
| Basileus Consulting Ltd | Professional & scientific | 2024 |
| Bath Court Residents' Asociation (Maidenhead) Limited | Households | 1975 |
| Batra Investment Limited | Real estate | 2022 |
| Battery Kingdom Ltd | Wholesale & retail | 2020 |
| Bay Gardens Productions Ltd | Information & communication | 2024 |
| Bay Tree Marquees Limited | Administrative & support | 2015 |
| Baylis Community Media CIC | Information & communication | 2022 |
| Baylis Media Ltd | Real estate | 1943 |
| Baytree Securities Limited | Real estate | 2021 |
| Bazaar Bizarre Limited | Wholesale & retail | 2024 |
| BBG Industries Limited | Financial services | 2014 |
| Bbgi (NI) 2 Limited | Professional & scientific | 2015 |
| Bbgi (NI) Limited | Professional & scientific | 2013 |
| Bbgi Holding Limited | Professional & scientific | 2011 |
| BBSTORE1 Ltd | Wholesale & retail | 2022 |
| BC Digital Limited | Information & communication | 2017 |
| BCS Autos Limited | Wholesale & retail | 2026 |
| BDP Industrial Limited | Professional & scientific | 2020 |
| BE a Warrior Foundation Ltd | Education | 2019 |
| BE Your Spirit Ltd | Other services | 2014 |
| Beacon Biostrategies Ltd | Professional & scientific | 2026 |
| Bean & Blend Coffee Co Ltd | Hospitality | 2024 |
| Beaulieu Southern Properties Limited | Real estate | 2024 |
| Beaumont Gate Consulting Ltd | Professional & scientific | 2025 |
| Beaumont Property Group Limited | Real estate | 2026 |
| Beauport Consulting Limited | Administrative & support | 2022 |
| Beauty Bonanza Ltd | Wholesale & retail | 2019 |
| Beauty Secret Spa Ltd | Other services | 2016 |
| Beazer Limited | Financial services | 1968 |
| BEB Boxes Limited | Wholesale & retail | 2023 |
| BEB Investments Limited | Real estate | 2022 |
| Becon (Precision) Engineering Manufacturers Limited | Manufacturing | 2001 |
| Bedford Education Partnership Holdings Limited | Financial services | 2003 |
| Bedford Education Partnership Limited | Financial services | 2003 |
| Bedo Consulting Limited | Administrative & support | 2023 |
| BEE a Sport Ltd | Wholesale & retail | 2024 |
| BEE Happy Club Ltd | Education | 2022 |
| Beech Films Ltd | Information & communication | 2022 |
| Beforebeam Limited | Financial services | 1996 |
| Beforeblend Limited | Financial services | 1996 |
| Being YOU Academy Ltd | Wholesale & retail | 2023 |
| Belgrave Imperial Group Ltd | Real estate | 2024 |
| Belinda Gears Limited | Professional & scientific | 2007 |
| Bell Cannon Ltd | Professional & scientific | 2026 |
| Bell Soft Ltd | Information & communication | 2012 |
| Bellerophon Book Keeping Ltd | Professional & scientific | 2025 |
| Bellerophon Capital Consultancy Limited | Financial services | 2018 |
| Bellerophon Capital Limited | Professional & scientific | 2023 |
| Bells Building Services Ltd | Construction | 2021 |
| Belmont Building and Renovation Limited | Construction | 2013 |
| Belmont Farm Management Limited | Administrative & support | 2013 |
| Belmont Local Ltd | Wholesale & retail | 2019 |
| Belmont Lodge Limited | Health & social care | 2007 |
| Belowzero Ltd | Information & communication | 2024 |
| Belt & Road Economic Enhancement Association Ltd | Health & social care | 2021 |
| Beltrame Solution Services Ltd | Wholesale & retail | 2024 |