| Blue Leaf Services Limited | Professional & scientific | 2024 |
| Blue Ocean Healthcare Limited | Administrative & support | 2021 |
| Bluebell UK Management 2018 Limited | Households | 2018 |
| Bluecap Corporation Limited | Financial services | 2017 |
| Bluestone Beddington 1 Ltd | Energy | 2023 |
| Bluestone Beddington 2 Ltd | Energy | 2023 |
| Bluestone Bexley 1 Ltd | Energy | 2023 |
| Bluestone Bexley 2 Ltd | Energy | 2024 |
| Bluestone Bonnybridge 1 Ltd | Energy | 2024 |
| Bluestone Butt Lane 1 Ltd | Energy | 2023 |
| Bluestone Cathkin 1 Ltd | Energy | 2024 |
| Bluestone Coatbridge Ltd | Energy | 2024 |
| Bluestone Dougliehill 1 Ltd | Energy | 2024 |
| Bluestone Drakelow 1 Ltd | Energy | 2023 |
| Bluestone Dryfield Ltd | Energy | 2025 |
| Bluestone East Lamberkin 1 Ltd | Energy | 2024 |
| Bluestone Emerald 1 Ltd | Energy | 2025 |
| Bluestone Energy Holdings Ltd | Energy | 2024 |
| Bluestone Energy Ltd | Energy | 2018 |
| Bluestone Frodsham 1 Ltd | Energy | 2023 |
| Bluestone Hawkesbury 1 Ltd | Energy | 2022 |
| Bluestone Laceys Farm Ltd | Energy | 2021 |
| Bluestone Laigh Park 1 Ltd | Energy | 2021 |
| Bluestone Lebanon Farm 1 Ltd | Energy | 2021 |
| Bluestone Lebanon Farm 2 Ltd | Energy | 2021 |
| Bluestone Linton-On-Ouse 1 Ltd | Energy | 2024 |
| Bluestone Linwood 1 Ltd | Energy | 2023 |
| Bluestone Llwyn-Onn 1 Ltd | Energy | 2020 |
| Bluestone Malcolmwood 1 Ltd | Energy | 2024 |
| Bluestone Malcolmwood Solar Ltd | Energy | 2025 |
| Bluestone Mitchell Farms 1 Ltd | Energy | 2021 |
| Bluestone Mount Pleasant Ltd | Energy | 2025 |
| Bluestone Ponthir 1 Ltd | Energy | 2020 |
| Bluestone Rettendon 1 Ltd | Energy | 2020 |
| Bluestone Rhadyr 1 Ltd | Energy | 2020 |
| Bluestone Rushcliffe Ltd | Energy | 2022 |
| Bluestone SEC 1 Ltd | Energy | 2024 |
| Bluestone ST Peters Lane 2 Ltd | Energy | 2022 |
| Bluestone Stalham 1 Ltd | Energy | 2021 |
| Bluestone Stanely 1 Ltd | Energy | 2024 |
| Bluestone Summerston 1 Ltd | Energy | 2024 |
| Bluestone Sunnydale Farm 1 Ltd | Energy | 2022 |
| Bluestone Trebugal 1 Ltd | Energy | 2021 |
| Bluestone Upminister 2 Ltd | Energy | 2024 |
| Bluestone Upminster Ltd | Energy | 2022 |
| Bluestone Woolshots Ltd | Energy | 2025 |
| Bluezone Limited | Real estate | 1984 |
| Blush Lane Boutique Ltd | Wholesale & retail | 2025 |
| Blustry Limited | Real estate | 2019 |
| Blyth Catamarans Ltd | Manufacturing | 2017 |
| Boating Leisure Services Limited | Manufacturing | 2013 |
| Boilertech Plumbing and Electrical Limited | Administrative & support | 2017 |
| Bolt Commercial Finance Ltd | Financial services | 2025 |
| Bolt Mortgages Ltd | Financial services | 2020 |
| Bond Bespoke Investments Ltd | Construction | 2019 |
| Bond Mews Residents Association | Households | 2016 |
| Boosey Mortgages Ltd | Financial services | 2022 |
| Boss Contractors Limited | Construction | 2024 |
| Bowen Developments Limited | Construction | 2017 |
| Bowen Paving Groundworks & Landscaping Specialist Ltd | Administrative & support | 2021 |
| Bowie Homes Ltd | Real estate | 2025 |
| Bowler Engineering Ltd | Manufacturing | 2011 |
| Bowman Cleaning Services Ltd | Administrative & support | 2011 |
| Bozzo Brasil Trading Limited | Extraterritorial | 1985 |
| Bpro Enterprise Limited | Administrative & support | 2017 |
| Bpro Recruitment Employment Agency Ltd. | Health & social care | 2008 |
| Bracci Installations Limited | Construction | 2002 |
| Brading Down Ltd | Administrative & support | 2026 |
| Brand Deadstock Limited | Wholesale & retail | 2008 |
| Breadon Properties Limited | Real estate | 2026 |
| Brenda's Diner Ltd | Hospitality | 2025 |
| Brennan Surgical Limited | Health & social care | 2014 |
| Bridges House Limited | Health & social care | 2023 |
| Brighthelmstone Investments Ltd | Real estate | 2005 |
| Brightlingsea Property Company Limited | Real estate | 2017 |
| Brigphil Limited | Other services | 2020 |
| Brilin Traditional Joinery & Fitout Specialist Ltd | Construction | 2017 |
| Bristow Roofing Limited | Construction | 2001 |
| Britannia Contracts UK Limited | Construction | 2016 |
| Britannia Court Limited | Real estate | 1989 |
| Briteux Healthcare UK Ltd | Health & social care | 2021 |
| Broadview Property Ltd | Information & communication | 2022 |
| Brockwell Park Ltd | Professional & scientific | 2023 |
| Brooklands Care Home Ltd | Health & social care | 2014 |
| Brother Lettings Limited | Real estate | 2019 |
| Brotherhood State Ltd | Wholesale & retail | 2025 |
| Broughton Properties (Essex) Limited | Real estate | 2013 |
| Bruk.Club Ltd | Health & social care | 2022 |
| Bruno's Fish and Chips Limited | Hospitality | 2020 |
| Brylo Ltd | Information & communication | 2026 |
| Bsjco Holdings Ltd | Financial services | 2022 |
| Bsjco Property Ltd | Real estate | 2018 |
| BSL Kids Ltd | Information & communication | 2025 |
| Bubble GUM Promotions Limited | Real estate | 2010 |
| Bubblegum Distribution and Workwear Ltd | Wholesale & retail | 2017 |
| Buckmaster Associates (U.K) Ltd | Financial services | 2017 |
| Buddha Aesthetics Ltd | Health & social care | 2023 |
| Build & Renew Ltd | Construction | 2021 |
| Build Assure Limited | Information & communication | 2025 |
| Buildtech Interiors Limited | Construction | 2013 |