| Blacksea Delivery Driver Services Ltd | Transport & logistics | 2021 |
| Blackstone Agents Ltd | Real estate | 2024 |
| Blackwell & Co. Travel Limited | Transport & logistics | 2025 |
| Blades Media Solutions Ltd | Professional & scientific | 2023 |
| Blades of Bearwood Limited | Other services | 2015 |
| Blair Home Care Ltd | Administrative & support | 2025 |
| Blake Dene Court (Southbourne) Limited | Households | 1976 |
| Blake Surveyors Ltd | Professional & scientific | 2014 |
| Blakes Decorating Ltd | Construction | 2011 |
| Blakes of London Limited | Construction | 2013 |
| Blakes Works Limited | Manufacturing | 2025 |
| Blandford Communications Ltd | Professional & scientific | 2019 |
| Blandford Demolition & Plant Hire Ltd | Construction | 2019 |
| Blandford Demolition Ltd | Construction | 2026 |
| Blandford Forklift Limited | Wholesale & retail | 1977 |
| Blandford Roofing Limited | Professional & scientific | 2008 |
| Blank Coffee Ltd | Hospitality | 2025 |
| Blasnic Limited | Real estate | 2026 |
| Blazej Lesniczak Services Ltd | Manufacturing | 2025 |
| Bleggie Ltd | Real estate | 2025 |
| Blend Broadstone Ltd | Wholesale & retail | 2025 |
| Blend Coffee Collective Ltd | Hospitality | 2023 |
| Blend on the Group Ltd | Financial services | 2026 |
| Blend Southbourne Ltd | Manufacturing | 2026 |
| Blenheim Court Management (Westbourne) Limited | Households | 1995 |
| Blenheim Mews (Westbourne) Management Limited | Households | 2003 |
| Blessed Construction Ltd | Other services | 2016 |
| Blessed One Ltd | Wholesale & retail | 2025 |
| Bleuseniorproductions Ltd | Information & communication | 2026 |
| Blhd Ltd | Extraterritorial | 2024 |
| Blink-Hq Limited | Information & communication | 2025 |
| Bliss Aviation Handling Ltd. | Transport & logistics | 2003 |
| Bliss Aviation Ltd. | Administrative & support | 1994 |
| Bliss Flames Ltd | Manufacturing | 2024 |
| Blizzard Limited | Extraterritorial | 2001 |
| Block and Barrel Ltd | Hospitality | 2019 |
| Block D Freshwater Drive (Hamworthy) Limited | Households | 2003 |
| Blockhold Residents Management Limited | Real estate | 1987 |
| Blocks Originals Ltd | Wholesale & retail | 2024 |
| Blockwave Ltd | Information & communication | 2025 |
| Blockwise Paving & Building Ltd | Construction | 2025 |
| Bloom and Berry Limited | Wholesale & retail | 2026 |
| Bloom and Success Limited | Other services | 2019 |
| Bloom Pathways CIC | Health & social care | 2026 |
| Bloom Social Ltd | Professional & scientific | 2024 |
| Bloom Your Life and Business Ltd | Manufacturing | 2014 |
| Blossom Childcare Nature Nursery Ltd | Health & social care | 2020 |
| Blossom Enterprises Limited | Wholesale & retail | 2011 |
| Blossom Escapes Ltd | Hospitality | 2021 |
| Blossom Properties Management Limited | Real estate | 2014 |
| Blossom Stores Ltd | Wholesale & retail | 2025 |
| Blossoms New Look Ltd | Administrative & support | 2020 |
| Blox Property (Poole) Limited | Professional & scientific | 2008 |
| BLU Heritage Ltd | Construction | 2018 |
| Blue ARC Steel Ltd | Construction | 2015 |
| Blue Bay Events Ltd | Other services | 2012 |
| Blue Bay Residents Limited | Real estate | 2012 |
| Blue Bay Technology Services Limited | Information & communication | 2019 |
| Blue Cedars Flat Management Company Limited | Households | 1990 |
| Blue Coast Laundry Ltd | Other services | 2025 |
| Blue Eagle Securities Ltd | Administrative & support | 2017 |
| Blue Eagle Security Limited | Administrative & support | 2014 |
| Blue FOX Investing Limited | Real estate | 2023 |
| Blue Grange Freehold Limited | Households | 2017 |
| Blue Hart Ltd | Real estate | 2025 |
| Blue Intelligence Limited | Information & communication | 2024 |
| Blue Jasmine Tapasia Ltd | Hospitality | 2026 |
| Blue JAY Books Ltd | Information & communication | 2021 |
| Blue Line National Transport Ltd | Transport & logistics | 2023 |
| Blue Lotus Enterprises Limited | Hospitality | 2025 |
| Blue Mountain Gear Ltd | Wholesale & retail | 2025 |
| Blue Ocean Chiropractic Limited | Health & social care | 2003 |
| Blue Ocean Consultancy & Management Limited | Professional & scientific | 2018 |
| Blue Onyx Limited | Hospitality | 2025 |
| Blue Palms Hotel Limited | Hospitality | 2019 |
| Blue Panda Limited | Manufacturing | 2003 |
| Blue Resolve Ltd | Information & communication | 2024 |
| Blue Sands Consultancy Limited | Information & communication | 2019 |
| Blue Shutter Properties Limited | Construction | 2025 |
| Blue Skies Lifestyle Limited | Administrative & support | 2005 |
| Blue Water Web Limited | Information & communication | 2009 |
| Blue Whale Consultancy Limited | Information & communication | 2021 |
| Bluebell Partnership Group Ltd | Professional & scientific | 2017 |
| Bluebell Student Properties Ltd | Real estate | 2018 |
| Blueberrytwist Ltd | Information & communication | 2001 |
| Bluebird Homes Ltd | Real estate | 2024 |
| Blueboch Incorporated Ltd | Administrative & support | 2019 |
| Bluechip Construction Services Limited | Construction | 1993 |
| Bluecorner Limited | Households | 1986 |
| Bluegreen People Ltd | Administrative & support | 2017 |
| Blueplug Limited | Health & social care | 2024 |
| Bluequinn Enterprises Ltd | Financial services | 2022 |
| Bluequinn Limited | Other services | 2015 |
| Blues Food Limited | Real estate | 2014 |
| Bluesnow Limited | Construction | 2002 |
| Blueswans Consulting Ltd | Professional & scientific | 2020 |
| Blueview Developments Ltd | Real estate | 2024 |
| Bluewaters Investments Ltd | Real estate | 2016 |
| Bluez Bruvers Limited | Agriculture & fishing | 2025 |
| Blumariin Limited | Construction | 2005 |