| BOW Tree Beauty Limited | Other services | 2025 |
| Bower Facilities Limited | Administrative & support | 2014 |
| Bower Industries Limited | Information & communication | 2021 |
| Bowie Construction Ltd | Construction | 2007 |
| Box Rental Ltd | Transport & logistics | 2015 |
| Boxer Motor Company Limited | Wholesale & retail | 2001 |
| Boyn Hill Close Management Company Limited | Households | 1965 |
| Boyn Hill Court Management Company Limited | Households | 1983 |
| BPB Old Company Limited | Information & communication | 2020 |
| BPN Construction Limited | Construction | 2017 |
| BPP Gifting Ltd | Administrative & support | 2020 |
| BR Buildscapes Ltd | Construction | 2025 |
| BR UK Holdings Limited | Real estate | 2025 |
| Braden Consultancy Limited | Professional & scientific | 2025 |
| Bradley Aesthetics Ltd | Health & social care | 2014 |
| Brain-Map Property Solutions Ltd | Real estate | 2023 |
| Brainstorm Communications Limited | Other services | 1997 |
| Bramley Studios Limited | Wholesale & retail | 2026 |
| Brandjuicer Limited | Manufacturing | 2024 |
| BRATI1 Ltd | Construction | 2025 |
| Brave Consultancy Ltd | Professional & scientific | 2020 |
| Brave Group Holdings Limited | Professional & scientific | 2025 |
| Brave Group Ltd | Professional & scientific | 2022 |
| Brave Within Advisory Limited | Professional & scientific | 2025 |
| Brave Within LLP | | 2022 |
| Braxtons Holdings Ltd | Real estate | 2023 |
| Bray Business Consulting Limited | Information & communication | 2020 |
| Bray Cars Ltd | Transport & logistics | 2023 |
| Bray Craning Limited | Professional & scientific | 2018 |
| Bray Cured Limited | Manufacturing | 2021 |
| Bray Cured on the High Street Ltd | Hospitality | 2022 |
| Bray Design Upholstery Limited | Manufacturing | 1994 |
| Bray Flowers Limited | Wholesale & retail | 2014 |
| Bray Hair Studio Ltd | Other services | 2009 |
| Bray Lake Ltd | Real estate | 2025 |
| Bray Marine Sales Ltd | Wholesale & retail | 1992 |
| Bray Studio Hire Ltd | Administrative & support | 2026 |
| Bray Tutoring Ltd | Education | 2025 |
| Bray Vines Ltd | Agriculture & fishing | 2025 |
| Bray Vineyard Ltd | Agriculture & fishing | 2025 |
| Braywick Associates Limited | Professional & scientific | 2013 |
| Braywick Heating Limited | Construction | 2021 |
| Braywood Tree Surgery Limited | Extraterritorial | 2013 |
| Braywoodside Developments Ltd | Construction | 2025 |
| Braywoodside Holdings Ltd | Financial services | 2025 |
| Breakthrough Partners Limited | Professional & scientific | 2019 |
| Breeze Productions Ltd | Administrative & support | 2018 |
| Brentor Developments 1 Ltd | Construction | 2023 |
| Brentor Developments 17-19 PR Ltd | Construction | 2025 |
| Brentor Developments 30GS Limited | Real estate | 2024 |
| Brentor Developments 386-388 AR Limited | Construction | 2025 |
| Brentor Developments Hillcrest Ltd | Construction | 2024 |
| Brentor Developments RS 2 Limited | Construction | 2025 |
| Brentor Developments RS 3 Limited | Construction | 2026 |
| Brentor Developments RS Limited | Construction | 2025 |
| Brentor Developments SJP Limited | Construction | 2025 |
| Brentor Developments West Cliff Limited | Construction | 2023 |
| Brentor Holdings Limited | Financial services | 2022 |
| Brentor Property Limited | Real estate | 2018 |
| Brentor Property Trading Limited | Real estate | 2021 |
| Briarwood Partners Alternatives Limited | Financial services | 2022 |
| Briarwood Partners Limited | Financial services | 2019 |
| Bridge Clinic ENT Limited | Health & social care | 2003 |
| Bridge Court (Taplow) Limited | Households | 2016 |
| Bridge Super Store Limited | Wholesale & retail | 2023 |
| Bridge Trading and Services Limited | Administrative & support | 2010 |
| Bridge View Management (Maidenhead) Limited | Hospitality | 1999 |
| Bridgecastle Properties Limited | Real estate | 1994 |
| Bridgegap Support Services Limited | Health & social care | 2023 |
| Bridgegate Electrical Limited | Construction | 1997 |
| Bridgegate Electrical Trustees Limited | Other services | 2025 |
| Bridgegate Holdings Limited | Financial services | 2020 |
| Bridgegate Literary Limited | Arts & recreation | 2023 |
| Bridgegate Properties Limited | Real estate | 2020 |
| Bridgewater Developments Limited | Real estate | 1995 |
| Bridgewater New Homes Limited | Real estate | 2007 |
| Bridgeway Digital Limited | Professional & scientific | 2019 |
| Brinley Vicker Limited | | 1976 |
| Bristal Developments Limited | Real estate | 2016 |
| Bristal Investments Limited | Hospitality | 2003 |
| Bristol & Avon Group Limited | Financial services | 2020 |
| Bristol & Avon Stone Supplies Limited | Wholesale & retail | 2020 |
| Bristol & Avon Transport & Recycling Ltd | Construction | 1993 |
| Bristow Construction Ltd | Construction | 2013 |
| Brit Asset Management Limited | Real estate | 2017 |
| Britannia 2000 Limited | Professional & scientific | 1997 |
| Britannia Silverworks Ltd | Manufacturing | 2026 |
| British Aerobatic Association Limited | Arts & recreation | 1974 |
| British Agricultural Services Limited | Professional & scientific | 1946 |
| British Colloids Limited | Professional & scientific | 1918 |
| British Ever Ready Limited | Professional & scientific | 1989 |
| Britten Tyres Limited | Wholesale & retail | 1992 |
| Broad Holdings Limited | Professional & scientific | 2003 |
| Broadcast Solutions (BS) UK Limited | Information & communication | 2019 |
| Broja Ventures Limited | Real estate | 2017 |
| Bronllety Hydro Limited | Energy | 2015 |
| Bronte Court Ltd | Households | 2019 |
| Brook and Swing Limited | Financial services | 2020 |
| Bruhati Solutions Ltd | Information & communication | 2018 |
| Bruhati Technologies Ltd | Information & communication | 2012 |