| Bedmar Housekeeping Ltd | Administrative & support | 2025 |
| Beech Landscapes (UK) Limited | Administrative & support | 2004 |
| Beeches Way Management Company Limited | Households | 1988 |
| Beechwood Manor (Henley-On-Thames) Management Company Limited | Households | 2024 |
| Beetroot Ventures Limited | Professional & scientific | 2020 |
| Before YOU DO Ltd | Information & communication | 2020 |
| Belleme Mews Management Company Ltd | Real estate | 2006 |
| Belliam Limited | Administrative & support | 2019 |
| Bells and Harmony Ltd | Other services | 2018 |
| Bellur Consultancy Limited | Information & communication | 2011 |
| Belmore Consultancy Ltd | Professional & scientific | 2016 |
| Belvedere Tiling Ltd | Construction | 2015 |
| Bemaya Ltd | Professional & scientific | 2024 |
| BEN Amor Barbers Limited | Other services | 2023 |
| BEN Clark Coaching Ltd | Other services | 2025 |
| Bengar Limited | Real estate | 2012 |
| Bennett's Tree Care Limited | Agriculture & fishing | 2012 |
| Bentley Intelligence Ltd | Information & communication | 2018 |
| Benweldsecure Ltd | Manufacturing | 2011 |
| BEO Home Ltd | Wholesale & retail | 2022 |
| Berberov Ltd | Other services | 2011 |
| Beresford & Cole Limited | Real estate | 2020 |
| Bering Heating Supplies Limited | Wholesale & retail | 1972 |
| Berkeley ST. Business Group Ltd | Professional & scientific | 2023 |
| Berks Car Station Ltd | Wholesale & retail | 2022 |
| Berkshire Advice Limited | Financial services | 2018 |
| Berkshire Artificial Grass Limited | Administrative & support | 2018 |
| Berkshire Board Cuts Ltd | Manufacturing | 2023 |
| Berkshire Broilers Ltd | Agriculture & fishing | 2025 |
| Berkshire Construction Group Limited | Real estate | 2025 |
| Berkshire Developments Limited | Real estate | 2001 |
| Berkshire Dive Centre Limited | Wholesale & retail | 2014 |
| Berkshire Divecrew Training 2012 Limited | Education | 2012 |
| Berkshire IFA Limited | Financial services | 2018 |
| Berkshire Land and Energy Limited | Professional & scientific | 2012 |
| Berkshire Living Limited | Real estate | 2015 |
| Berkshire Mortgage Solutions Ltd | Financial services | 2024 |
| Berkshire Motor Works Ltd | Wholesale & retail | 2008 |
| Berkshire Perinatal Psychology Ltd | Health & social care | 2025 |
| Berkshire Plastering Services Ltd | Construction | 2026 |
| Berkshire Removals Limited | Transport & logistics | 2012 |
| Berkshire Removals Properties Limited | Real estate | 2017 |
| Berkshire Video Services Ltd | Information & communication | 2019 |
| Berkshire Waste Solutions Ltd | Water & waste | 2019 |
| Berkshire Wellness Circle CIC | Other services | 2022 |
| Berkshire Wills Limited | Financial services | 2023 |
| Berry Brook Homes Limited | Real estate | 2009 |
| Bertram Todd Consultancy Ltd | Professional & scientific | 1996 |
| Bertram Todd Limited | Professional & scientific | 2009 |
| Best Interests Productions Limited | Information & communication | 2020 |
| Best Price Cars 4 U Limited | Wholesale & retail | 2020 |
| Besties Cafe Limited | Hospitality | 2024 |
| Better Healthcare Services Limited | Administrative & support | 1998 |
| Better Networks UK Ltd | Information & communication | 2015 |
| Better Public Speaking Ltd | Wholesale & retail | 2024 |
| Bettscapes Limited | Administrative & support | 2016 |
| Bevan & Bevan Holdings Limited | Financial services | 2025 |
| Bevan Gate Management Limited | Real estate | 2011 |
| Bevhall Properties Limited | Real estate | 2025 |
| Bexley Court Flat Management (Reading) Limited | Households | 1979 |
| Bexprt Ltd | Information & communication | 2018 |
| Beyond Agency (Holdings) Limited | Financial services | 2024 |
| Beyond Boujie Limited | Other services | 2024 |
| Beyond PR (Agency) Limited | Professional & scientific | 2000 |
| BGP Trade Property Limited | Extraterritorial | 2022 |
| BH23 Consulting Ltd | Professional & scientific | 2019 |
| Bhagya's Kitchen Ltd | Hospitality | 2017 |
| Bhatt-Consulting Ltd | Information & communication | 2006 |
| Bianca Herholdt Design Ltd | Professional & scientific | 2025 |
| Big Bear Catering Limited | Hospitality | 2020 |
| Big CC Racing Limited | Manufacturing | 1999 |
| Big Mutts Ltd | Wholesale & retail | 2026 |
| Big Smoke Creative Limited | Professional & scientific | 2008 |
| Bigjimny Services Limited | Wholesale & retail | 2016 |
| Biglove.Ai Ltd | Wholesale & retail | 2025 |
| Bill Watson Limited | Information & communication | 2017 |
| Bilsport Limited | Real estate | 2016 |
| Bindon Management Consultancy Limited | Professional & scientific | 2026 |
| Bio-Technology Associates Limited | Administrative & support | 1996 |
| Bioqpharma Consultancy Limited | Information & communication | 2020 |
| Birchfield Construction Ltd | Construction | 2016 |
| Birchmore Properties Limited | Real estate | 2016 |
| Birchmore Property Services Limited | Households | 2016 |
| Bird Charles Estates Limited | Real estate | 2018 |
| Bird Charles Surveyors Limited | Administrative & support | 2013 |
| Birdwin Services Limited | Professional & scientific | 2025 |
| Bite Insight Ltd | Information & communication | 2026 |
| BIZ Accounting Solutions Ltd | Professional & scientific | 2011 |
| Bizcom TV Limited | Information & communication | 2010 |
| BJP Holdings Trustees Limited | Professional & scientific | 2022 |
| BK Central Limited | Wholesale & retail | 2022 |
| BK Stunts Ltd | Other services | 2018 |
| BL Active Ltd | Professional & scientific | 2021 |
| Black Cat Engineering Ltd | Administrative & support | 2023 |
| Black Cat Imports Ltd | Wholesale & retail | 2026 |
| Black Swann Consulting Limited | Information & communication | 2017 |
| Blackaller TM Consults Limited | Administrative & support | 2025 |
| Blackbirds Consultancy Limited | Health & social care | 2022 |
| Blackeyed Theatre Ltd | Arts & recreation | 2014 |
| Blackstar Projects Ltd | Construction | 2026 |