| Brechin Property Consultants Limited | Real estate | 2016 |
| Breedon Place Management Company Limited | Households | 2018 |
| Brent-Wood-Burners & Bathrooms Limited | Wholesale & retail | 2010 |
| Brentcross Solutions Limited | Professional & scientific | 2018 |
| Brenthall Park (Commercial) Limited | Extraterritorial | 1989 |
| Brenthall Park (Infrastructure) Limited | Extraterritorial | 1989 |
| Brenthall Park (One) Limited | Extraterritorial | 1989 |
| Brenthall Park (Three) Limited | Extraterritorial | 1989 |
| Brenthall Park Limited | Extraterritorial | 1985 |
| Brentleigh Court Limited | Households | 2004 |
| Brents Holdings Limited | Financial services | 2020 |
| Brents of Brentwood Limited | Financial services | 1963 |
| Brentwood Accountancy Ltd | Professional & scientific | 2001 |
| Brentwood Apex Ltd | Education | 2026 |
| Brentwood Barbers Limited | Other services | 2012 |
| Brentwood Boilers & Air Conditioning Limited | Manufacturing | 2014 |
| Brentwood Brewing Company Limited | Manufacturing | 2006 |
| Brentwood Build Makers Ltd | Manufacturing | 2019 |
| Brentwood Building Services Limited | Construction | 2019 |
| Brentwood Care Limited | Health & social care | 2008 |
| Brentwood Central Boxing Club CIC | Health & social care | 2023 |
| Brentwood Chiropody Surgery Limited | Health & social care | 2016 |
| Brentwood Community Transport | Transport & logistics | 2009 |
| Brentwood Construction Ltd | Construction | 2025 |
| Brentwood Day Nursery Limited | Health & social care | 2014 |
| Brentwood Decorators Limited | Construction | 2026 |
| Brentwood Discount Cladding Ltd | Wholesale & retail | 2014 |
| Brentwood Embroidery Limited | Manufacturing | 2008 |
| Brentwood Fencing Supplies Limited | Construction | 2013 |
| Brentwood Festival Limited | Hospitality | 2012 |
| Brentwood Flooring Ltd | Construction | 2016 |
| Brentwood Grooming Academy Limited | Education | 2021 |
| Brentwood Guest House Limited | Hospitality | 2010 |
| Brentwood Heating Ltd | Construction | 2023 |
| Brentwood Homes Limited | Health & social care | 1996 |
| Brentwood Honey Limited | Agriculture & fishing | 2025 |
| Brentwood International Cultural Festival CIC | Education | 2025 |
| Brentwood Joinery Limited | Manufacturing | 1979 |
| Brentwood Kitchen & Interiors Company Limited | Manufacturing | 2016 |
| Brentwood Lock & Safe Co Ltd | Wholesale & retail | 1999 |
| Brentwood Medical Aesthetics Ltd | Health & social care | 2025 |
| Brentwood Medics Ltd | Health & social care | 2015 |
| Brentwood Metalworks Ltd | Manufacturing | 2023 |
| Brentwood Mini Market Ltd | Wholesale & retail | 2017 |
| Brentwood Orthodontic & Implant Centre Ltd | Health & social care | 2011 |
| Brentwood Property Services Limited | Real estate | 2017 |
| Brentwood Recycle and Resell Limited | Wholesale & retail | 2020 |
| Brentwood Roman Catholic Diocese Trustee(The) | Other services | 1948 |
| Brentwood School Design & Build Limited | Construction | 2021 |
| Brentwood School Enterprises | Arts & recreation | 1986 |
| Brentwood Secretaries Ltd | Other services | 2007 |
| Brentwood Spice UK Ltd | Hospitality | 2024 |
| Brentwood Technology Limited | Professional & scientific | 2018 |
| Brentwood Timber Supplies Limited | Wholesale & retail | 2006 |
| Brentwood Tree Care Ltd | Administrative & support | 2014 |
| Brentwood Ursuline Convent High School | Education | 2012 |
| Brentwood Windows Doors and Joinery Company Limited | Administrative & support | 2021 |
| Brentwood Youth BC CIC | Arts & recreation | 2025 |
| Bretaye Properties Limited | Real estate | 1961 |
| Brewandsipcoffee Ltd | Hospitality | 2025 |
| Brewster Trading Limited | Administrative & support | 2014 |
| Brian Scaddan Associates Limited | Education | 1995 |
| Brick Avenue Ltd | Real estate | 2026 |
| Bricklayers Arms First Management Company Limited | Households | 1993 |
| Bridgepool Beach Limited | Households | 2020 |
| Bridgeside Court Residents Association Limited | Real estate | 1996 |
| Bridget Mccrum Limited | Arts & recreation | 2016 |
| Bright Coaches Limited | Transport & logistics | 2025 |
| Bright Women Organisation L.E Ltd | Other services | 2025 |
| Brighter Days Together CIC | Education | 2025 |
| Brightflow Limited | Administrative & support | 2026 |
| Brightlemon Limited | Information & communication | 2003 |
| Brightminds GRC Limited | Wholesale & retail | 2025 |
| Brightstone Properties Limited | Real estate | 2020 |
| Brightwell Country Parks Ltd | Hospitality | 2020 |
| Brij UK Ltd | Real estate | 2017 |
| Brilliant Path Limited | Administrative & support | 2005 |
| Bristol Manufacturing Limited | Financial services | 2012 |
| Britanic Properties Limited | Real estate | 1996 |
| Britannia Cleaning Limited | Administrative & support | 1989 |
| Britbloc Management Ltd | Administrative & support | 2022 |
| British Drilling Association Limited | Other services | 1977 |
| Britplan Security Solutions Limited | Administrative & support | 2002 |
| BRITSK9 Ltd | Administrative & support | 2024 |
| Brjb Holdings Limited | Financial services | 2023 |
| Broadacre Holdings Limited | Construction | 2026 |
| Broadleigh Consulting Ltd | Information & communication | 2025 |
| Broadwalk Supplements Ltd | Wholesale & retail | 2025 |
| Broadway Place Limited | Construction | 2019 |
| Brockspark Consulting Services Ltd | Professional & scientific | 2023 |
| Broda&Son Transportation Limited | Construction | 2018 |
| Bromley Regeneration (Calverley Close) LLP | | 2021 |
| Bromley Regeneration (Pike Close) LLP | | 2021 |
| Bronzen Limited | Wholesale & retail | 2026 |
| Brook Consulting Services Limited | Information & communication | 2002 |
| Brook Cottage (Essex) Limited | Real estate | 2015 |
| Brooklands Builders Ltd | Construction | 2009 |
| Brookmill Meadows LLP | | 2023 |
| Brooks Property Consultants Ltd | Households | 2020 |
| Broom Consultants EOT Limited | Financial services | 2023 |