| Blessed Estates Limited | Construction | 2025 |
| Bletchingley Farm Court (Management Company) Ltd | Real estate | 2021 |
| Blew Site Services Ltd | Water & waste | 2025 |
| Blin Global Freight and Logistics Ltd | Transport & logistics | 2025 |
| Bliss Housing Management Limited | Real estate | 2020 |
| Bliss Moments Ltd | Health & social care | 2018 |
| Blitzen Rudolph Ltd | Wholesale & retail | 2023 |
| Blocfit Ltd | Arts & recreation | 2018 |
| Blocked Drain Specialists Limited | Construction | 2012 |
| Blockhouse Management Ltd | Hospitality | 2014 |
| Blond Rosemary Ltd | Real estate | 2024 |
| Blondor Services Ltd | Professional & scientific | 2025 |
| Bloom & Gold Consulting Ltd | Information & communication | 2011 |
| Bloom and Lume Ltd | Wholesale & retail | 2026 |
| Bloom Services Limited | Administrative & support | 2016 |
| Bloom Vine Limited | Manufacturing | 2016 |
| Bloomview Properties Limited | Real estate | 2026 |
| Blossom Forth Multi Concept Limited | Wholesale & retail | 2024 |
| Blossom Speech and Language Therapy Ltd | Health & social care | 2022 |
| BLU Rhino Ltd | Information & communication | 2024 |
| Blue Car Design Limited | Real estate | 2010 |
| Blue Duff Homes Limited | Real estate | 2021 |
| Blue Earth Developments Ltd | Construction | 2014 |
| Blue Endeavour Limited | Information & communication | 2012 |
| Blue First Ltd | Manufacturing | 2021 |
| Blue Flower Coffee Lounge Limited | Wholesale & retail | 2016 |
| Blue Giraffe Dartford Limited | Wholesale & retail | 2025 |
| Blue Haze Investment Limited | Real estate | 2016 |
| Blue House Estates Limited | Administrative & support | 1960 |
| Blue Lavender Music Limited | Arts & recreation | 2025 |
| Blue Mayne Limited | Administrative & support | 2018 |
| Blue Oak Homes Ltd | Real estate | 2026 |
| Blue Print Publishing Ltd | Information & communication | 2018 |
| Blue Renewables Ltd | Construction | 2021 |
| Blue Rocket Accounting Ltd | Professional & scientific | 2008 |
| Blue Rocket SME Services Ltd | Financial services | 2013 |
| Blue Star Express (Dartford) Ltd | Hospitality | 2025 |
| Blue Starz Consultant Ltd | Financial services | 2020 |
| Blue Summit Developers Ltd | Construction | 2024 |
| Blue Velvet Properties Limited | Construction | 2015 |
| Blue WIG Holdings Ltd | Financial services | 2022 |
| Bluebadger Limited | Professional & scientific | 2013 |
| Bluebed Suites Ltd | Real estate | 2023 |
| Bluebell Data Solutions Limited | Information & communication | 2023 |
| Bluebell Recruitment Ltd | Administrative & support | 2024 |
| Bluebird Home Services Ltd | Construction | 2021 |
| Bluebox Executive Group Ltd | Administrative & support | 2019 |
| Bluecliffe Services Limited | Information & communication | 2006 |
| Bluecliffehomes Ltd | Real estate | 2021 |
| Bluecraft Consulting Ltd | Professional & scientific | 2022 |
| Bluelime Construction Services Limited | Construction | 2018 |
| Bluelime Home Design LLP | | 2017 |
| Bluelime Retail Limited | Construction | 2006 |
| Blueprint Cyber Security Ltd | Administrative & support | 2020 |
| Blueprint Executive Search Limited | Administrative & support | 2017 |
| Blueprint IT Consulting Ltd | Information & communication | 2024 |
| Bluerock Trading Limited | Wholesale & retail | 2020 |
| Bluetax Accountants Ltd | Professional & scientific | 2025 |
| Bluevelvety Limited | Other services | 2020 |
| Bluewater Trade Ltd | Wholesale & retail | 2025 |
| Bluewave Consulting (UK) Limited | Professional & scientific | 2013 |
| Bluewire Box Limited | Administrative & support | 2023 |
| Blumid Ltd | Administrative & support | 2023 |
| BM Plus Limited | Real estate | 2022 |
| BM Window Cleaning Ltd | Administrative & support | 2021 |
| Bmfa Properties Limited | Real estate | 2018 |
| BMM Properties Limited | Construction | 2021 |
| Bmmm Services Limited | Information & communication | 2022 |
| Bmos Prime Limited | Real estate | 2008 |
| BN Dartford Ltd | Wholesale & retail | 2018 |
| BN Retail Ltd | Wholesale & retail | 2024 |
| BNE Aequitas Ltd | Transport & logistics | 2026 |
| BNM Private Limited | Real estate | 2025 |
| BNP Developments Ltd | Professional & scientific | 2024 |
| Boarco Ltd | Wholesale & retail | 2019 |
| Boateng Properties Limited | Real estate | 2021 |
| Boatfront Ltd | Information & communication | 2026 |
| BOB Skips Ltd | Water & waste | 2022 |
| Bobalong Limited | Financial services | 2024 |
| Bobo & CHA Ltd | Hospitality | 2022 |
| BOD Cleaning Services Ltd | Administrative & support | 2024 |
| Bodie Pilates Ltd | Arts & recreation | 2025 |
| Bodysculpting Empire Ltd | Other services | 2022 |
| Bodyshine Limited | Other services | 2016 |
| Bodyshots Boxing Academy Limited | Education | 2020 |
| Bodyshots Limited | Arts & recreation | 2024 |
| Bodyshots Supplements Limited | Manufacturing | 2024 |
| Boiler Maestro Limited | Construction | 2019 |
| Bojetcares Services Ltd | Administrative & support | 2017 |
| Bojo and Co Limited | Health & social care | 2014 |
| Bojo Building and Construction Limited | Construction | 2020 |
| Bolbod Consulting Ltd | Information & communication | 2021 |
| Bolfas Group Ltd | Construction | 2025 |
| Boltem Limited | Health & social care | 2022 |
| Boltem Property Limited | Real estate | 2022 |
| Bolton Edit Ltd | Information & communication | 2026 |
| Bonarda Ltd | Construction | 2018 |
| Boning Services Limited | Health & social care | 2019 |
| Bonser & Bonser Limited | Real estate | 2015 |
| Bonum Contemporary Construction Ltd | Construction | 2011 |