| Brassknocker Farm Limited | Agriculture & fishing | 2015 |
| Brassmill Enterprise Centre (Management) Limited | Real estate | 1987 |
| Brave Careers Ltd | Administrative & support | 2026 |
| Bravo Alpha One Four Limited | Real estate | 2020 |
| Braydon Manor Renewable Energy Limited | Energy | 2014 |
| Braysdown Stables Ltd | Real estate | 2016 |
| BRC Property Investment Co Ltd | Real estate | 2024 |
| Brea Avalon LLP | | 2008 |
| Breaking Wave Group Limited | Arts & recreation | 2025 |
| Breakthrough Case Management Ltd | Health & social care | 2018 |
| Breeze Mortgages Ltd | Financial services | 2021 |
| Breeze Plumbing and GAS Ltd | Construction | 2022 |
| Bremardan Consultants Ltd | Professional & scientific | 2023 |
| Brendan Burnell Plumbing and Heating Ltd | Construction | 2018 |
| Bretsa Early Years Limited | Administrative & support | 2020 |
| Brew & Tipple Ltd | Hospitality | 2022 |
| Brew Dairy Ltd | Professional & scientific | 2019 |
| Brewery Inn Holdings Ltd | Hospitality | 2018 |
| Brian Fielding Limited | Information & communication | 2007 |
| Brian Peters Limited | Wholesale & retail | 1987 |
| Brian Property Ltd | Real estate | 2022 |
| Bricqs and Beyond HR Ltd | Administrative & support | 2016 |
| Bridge Learning Technologies Ltd | Information & communication | 2017 |
| Bridge River Consulting Ltd | Information & communication | 2018 |
| Bridge Software Development Ltd | Information & communication | 2018 |
| Bridgetower Consultants Ltd | Professional & scientific | 2015 |
| Bridport House Management Limited | Households | 1990 |
| Bright Dark (UK) Ltd | Arts & recreation | 2014 |
| Bright Day Limited | Information & communication | 2008 |
| Bright Soul Ltd | Arts & recreation | 2011 |
| Bright Story Ltd | Arts & recreation | 2018 |
| Bright Studio Architects Ltd | Professional & scientific | 2022 |
| Bright Thinking Studio Ltd | Other services | 2025 |
| Bright West Trading Limited | Wholesale & retail | 2015 |
| Brighter People Limited | Administrative & support | 2019 |
| Brighton Visions Limited | Real estate | 2006 |
| Brightwild Ventures Ltd | Financial services | 2025 |
| Bristol & Bath Limited | Administrative & support | 2017 |
| Bristol Blue Glass Limited | Manufacturing | 1990 |
| Bristol Costume Services Limited | Arts & recreation | 2004 |
| Bristol Cushion Company Limited | Manufacturing | 2013 |
| Bristol Inkjet Limited | Manufacturing | 2018 |
| Bristol Systems Limited | Extraterritorial | 2023 |
| Bristol Tour Depot Ltd | Transport & logistics | 2018 |
| Bristol Women in Business CIC | Administrative & support | 2020 |
| Britelines Limited | Wholesale & retail | 2013 |
| British Association for Modern Mosaic | Arts & recreation | 2019 |
| British Bobsleigh and Skeleton Association Ltd | Arts & recreation | 1980 |
| Britts of Bath Limited | Other services | 2014 |
| Brixey Auto Repairs Limited | Wholesale & retail | 1996 |
| Brlpp CIC | Arts & recreation | 2023 |
| Broadleaf Bidco Limited | Financial services | 2018 |
| Broadleaf Holdco Limited | Financial services | 2018 |
| Broadleaf Midco Limited | Financial services | 2018 |
| Broadleaf Newco 2 Limited | Information & communication | 2021 |
| Broadsword Properties Limited | Professional & scientific | 1984 |
| Brochris Enterprises Limited | Wholesale & retail | 2019 |
| Brock Aesthetics Ltd | Other services | 2023 |
| Brock Studio Consulting Limited | Professional & scientific | 2021 |
| Brockham END Ltd | Households | 2008 |
| Broll Media Ltd | Manufacturing | 2023 |
| Brompton House Car Park Management Company Bath Ltd | Households | 2012 |
| Brompton House Management Company Bath Limited | Households | 2005 |
| Brook House (SW) Developments Limited | Construction | 2021 |
| Brookfields Meadow Management Company Limited | Households | 2023 |
| Brookmans Community Green Grocers Ltd | Wholesale & retail | 2020 |
| Brooks Hotels Limited | Hospitality | 2007 |
| Brow Works Ltd | Other services | 2022 |
| Browndog Music Ltd | Information & communication | 2012 |
| Brownhen Solutions Ltd | Professional & scientific | 2013 |
| Browning Urban Nest Ltd | Real estate | 2025 |
| Browns Electrical (Bath) Ltd | Construction | 2018 |
| Brownstone Trading Limited | Wholesale & retail | 2018 |
| Bruce Wills Production Sounds Limited | Professional & scientific | 2019 |
| Brunel Engraving Holdings Limited | Professional & scientific | 2026 |
| Brunel Health & Safety Services Limited | Professional & scientific | 2002 |
| Brunswick Gate (Bath) Management Company Limited | Households | 2014 |
| Brunswick Place Management Company Limited | Households | 1985 |
| Bryanston Nursery @ Marble Arch Limited | Health & social care | 2017 |
| Brytin Ltd | Manufacturing | 2023 |
| Bryworth Farm Estates Limited | Construction | 2020 |
| BS16 Limited | Construction | 2014 |
| BSM Stone Conservation & Restoration Ltd | Manufacturing | 2025 |
| Btfm Ltd | Administrative & support | 2018 |
| BTK Turner Limited | Real estate | 2024 |
| Buckler Engineering Services Limited | Manufacturing | 1999 |
| Buckler Ltd | Professional & scientific | 2023 |
| Buckley Health Consultancy Limited | Health & social care | 2016 |
| Bude Hotel Limited | Hospitality | 2021 |
| BUG Inc Limited | Professional & scientific | 2023 |
| Bugs Investment Limited | Financial services | 2022 |
| Build Carbon Zero Limited | Professional & scientific | 2020 |
| Build Tech (Southwest) Limited | Construction | 2019 |
| Builder Ability Limited | Construction | 2023 |
| Builders of Bath Limited | Construction | 2011 |
| Building and Project Management (Bath) Limited | Construction | 2015 |
| Building Better Products Ltd | Information & communication | 2019 |
| Building Consensus Limited | Professional & scientific | 2021 |
| Buildwales Homes Limited | Construction | 1995 |
| Built by Carpenter Limited | Construction | 2026 |