| Brewing (Enterprises) Limited | Hospitality | 2011 |
| Breydon Ventures Ltd | Extraterritorial | 2024 |
| Brian COX & Company (Lettings) Ltd | Real estate | 2020 |
| Brian Doogue Haulage Limited | Transport & logistics | 2003 |
| Briano UK Limited | Information & communication | 2026 |
| Briar Wilson Carter Limited | Professional & scientific | 2024 |
| Brick Almond Productions Ltd | Administrative & support | 2022 |
| Brick and Gold Investments Limited | Real estate | 2013 |
| Brick Farm Management Limited | Households | 2003 |
| Brickclean London Ltd | Construction | 2023 |
| Brickhouse Holdings Investments Limited | Financial services | 2023 |
| Brickhouse Investments Ltd | Real estate | 2020 |
| Brickk Limited | Transport & logistics | 2025 |
| Bricklehampton Classic Care Limited | Real estate | 2012 |
| Brickline Construction Ltd | Manufacturing | 2017 |
| Bricks & Tea Limited | Real estate | 2021 |
| Bricks Europe Limited | Administrative & support | 2023 |
| Brickstone (U.K.) Ltd | Construction | 2025 |
| Bricktex SPV Ltd | Extraterritorial | 2018 |
| Brickvest Capital Limited | Real estate | 2025 |
| Bridal With a Twist Limited | Wholesale & retail | 2010 |
| Brideshead Limited | Extraterritorial | 1988 |
| Bridge Rock Financial Limited | Financial services | 2017 |
| Bridgefield Real Estates and Investments Limited | Real estate | 2021 |
| Bridgepoint Education Ltd | Education | 2026 |
| Bridgerise Consulting Ltd | Professional & scientific | 2025 |
| Bridges Wharf Battersea Management Limited | Households | 2008 |
| Bridgewater Solutions Limited | Professional & scientific | 2018 |
| Bridgeway Fostering Limited | Health & social care | 2026 |
| Bridport Holdings Limited | Financial services | 2019 |
| Bridport Interiors Limited | Construction | 2004 |
| Bridport Joinery Contracts Limited | Construction | 2004 |
| Bridport Properties Limited | Construction | 2004 |
| Bridport Storefitters Limited | Construction | 2006 |
| Bright Auto Limited | Wholesale & retail | 2015 |
| Bright Bear Limited | Hospitality | 2015 |
| Bright Beginnings Hertfordshire Holdings Ltd | Education | 1999 |
| Bright Beginnings Hertfordshire Ltd | Health & social care | 2025 |
| Bright Dental Limited | Health & social care | 2024 |
| Bright Express Cleaning Services Ltd | Administrative & support | 2025 |
| Bright Future Consultants Limited | Professional & scientific | 2019 |
| Bright Futures SC Ltd | Health & social care | 2023 |
| Bright Gems Nursery Club TH Ltd | Health & social care | 2025 |
| Bright Gems Nursery the Sessile Ltd | Health & social care | 2025 |
| Bright Horizon Books Ltd | Information & communication | 2012 |
| Bright Ideas Teaching and Learning Ltd | Education | 2010 |
| Bright Little Stars Harrow Limited | Education | 2015 |
| Bright Mind Academy Harrow Ltd | Education | 2011 |
| Bright Minds Global Ltd | Education | 2025 |
| Bright Path Foundation CIC | Administrative & support | 2025 |
| Bright Rising Stars Ltd | Education | 2023 |
| Bright Star Nursery Ltd | Health & social care | 2021 |
| Bright Star Payroll Services Limited | Administrative & support | 2017 |
| Bright Stars Entertainment Limited | Arts & recreation | 2019 |
| Bright Stars Talent Hunt Ltd | Arts & recreation | 2018 |
| Bright Valeting Group Limited | Other services | 2016 |
| Brightbuild Contractors Ltd | Construction | 2023 |
| Brighter Minds Centre Ltd | Education | 2022 |
| Brightkey Properties Ltd | Real estate | 2025 |
| Brightsmile (Epsom) Limited | Health & social care | 2025 |
| Brightsmile (Isleworth) Limited | Health & social care | 2025 |
| Brightsmile (Tadworth) Limited | Health & social care | 2025 |
| Brightsmile Ltd | Health & social care | 2009 |
| Brightstar Holdings LLP | | 2025 |
| Brightstart Childcare & Education Limited | Education | 2006 |
| Brighttots Childminder Limited | Health & social care | 2017 |
| Brightwells Farm Estate Ltd | Real estate | 2024 |
| Brikonia Corporation Limited | Wholesale & retail | 2003 |
| Briks Holdings Ltd | Real estate | 2019 |
| Brill CON Ella Ltd. | Other services | 2024 |
| Brilliant Marketing Company Limited | Information & communication | 2022 |
| Brink Innovation Limited | Professional & scientific | 2017 |
| Brinkler Limited | Real estate | 2022 |
| Brisland Holdings Limited | Financial services | 2023 |
| Brissettry Ltd | Information & communication | 2014 |
| Bristek Limited | Wholesale & retail | 2025 |
| Bristle Hair & Fibre Trading Limited | Wholesale & retail | 2003 |
| Bristol Building Masters Limited | Construction | 2025 |
| Brit Bricks Investment Ltd | Real estate | 2022 |
| Brit Bricks Trading Ltd | Real estate | 2025 |
| Brit Broz Ltd | Wholesale & retail | 2025 |
| Brit Care Health Ltd | Health & social care | 2023 |
| Britania Flooring & Decor Ltd | Construction | 2025 |
| Britannia Investment Holdings Limited | Real estate | 2023 |
| Britannia Pubs Limited | Construction | 2017 |
| Britannic Qualifications Academy Ltd | Education | 2026 |
| Britbricks Ltd | Real estate | 2017 |
| Britcard Solutions Ltd | Wholesale & retail | 2025 |
| Britdesign Ltd | Construction | 2025 |
| Brite Motoring Limited | Financial services | 2018 |
| Britfame Limited | Manufacturing | 1986 |
| Britindia Stores Ltd | Wholesale & retail | 2026 |
| British Asian Fusion Ltd | Hospitality | 2023 |
| British Chamber of Commerce in Kazakhstan | Other services | 2014 |
| British Institute of Verbatim Reporters | Other services | 1887 |
| British Tissues (Velvet) Limited | Professional & scientific | 1937 |
| Britlink Cargo & Trade Ltd | Wholesale & retail | 2024 |
| Britlit Publishing Hub Ltd | Information & communication | 2026 |
| Britminster Ltd | Wholesale & retail | 2023 |
| Britrom Ltd | Construction | 2016 |