| BDC Southern Ltd | Construction | 2015 |
| Beach HUT Investment Limited | Real estate | 2020 |
| Beachlands Care Ltd | Health & social care | 2014 |
| Bear Security Limited | Administrative & support | 2017 |
| Beardwell Holdings Limited | Professional & scientific | 2002 |
| Beau-K Limited | Wholesale & retail | 2019 |
| Beaumont Finance Limited | Financial services | 2022 |
| Beaumont Group Investments Limited | Financial services | 2023 |
| Beaumont Property Estates Ltd | Real estate | 2022 |
| Beaumont Property Investments Ltd | Real estate | 2018 |
| Bedford Park Developments Limited | Administrative & support | 2006 |
| Bedford Park Strategic Ltd | Real estate | 2014 |
| Beech Homes Limited | Construction | 2012 |
| Beech Homes Properties and Developments Ltd | Construction | 2018 |
| Beech Loxwood Limited | Construction | 2014 |
| Beech Merrydown Limited | Construction | 2014 |
| Beer ME Brewery Limited | Wholesale & retail | 2023 |
| Bees Homes Property Ltd | Real estate | 2020 |
| Beesting Ventures Limited | Professional & scientific | 2026 |
| Believing Ltd | Construction | 2024 |
| Bellevista Contracting Limited | Construction | 2025 |
| Belmont Court Residents Association Ltd | Households | 2014 |
| BEN Griffiths Music Ltd | Arts & recreation | 2016 |
| Benandan Limited | Real estate | 2014 |
| Benbrook Consulting Limited | Professional & scientific | 2015 |
| Benchmark Homes Limited | Real estate | 2010 |
| Benn Hogan Development Group Limited | Construction | 2025 |
| Berny's Ltd | Construction | 2024 |
| Berties Fish & Chips Limited | Hospitality | 2011 |
| Bertini Limited | Professional & scientific | 2003 |
| Bespoke Blinds & Shutters (South East) Ltd | Wholesale & retail | 2015 |
| Bespoke Henley Joinery Ltd | Construction | 2018 |
| Besport Coaching Limited | Arts & recreation | 2025 |
| Between Oceans Limited | Manufacturing | 2025 |
| Bevan Property Holdings Limited | Real estate | 2018 |
| Bevan Roper Ltd | Administrative & support | 2018 |
| Bexhill Nbar BX3 (Management Company) Ltd | Construction | 2024 |
| BFG Mortgages Limited | Financial services | 2013 |
| BG Ward Limited | Real estate | 2018 |
| BH Freehold Property Ltd | Real estate | 2022 |
| BH Leasehold Properties Ltd | Real estate | 2024 |
| Bhardwaj Estates Limited | Real estate | 2021 |
| BHC Construction Ltd | Construction | 2013 |
| Biggs Developments Limited | Extraterritorial | 2024 |
| Birchwood Knight Limited | Administrative & support | 2009 |
| Birmingham Orthopaedic Oncology Service LLP | | 2023 |
| Bisse Limited | Information & communication | 2002 |
| BL Kilshaw Ltd | Manufacturing | 2025 |
| Black Dog Hill Estates Ltd | Manufacturing | 2014 |
| Black Ladder Construction Limited | Construction | 2019 |
| Black Stone Investments Ltd | Administrative & support | 2010 |
| Black Widows (Sussex) Ltd | Financial services | 2020 |
| Black Widows Bikers Ltd | Financial services | 2020 |
| Blackbird Secretarial Ltd | Administrative & support | 2021 |
| Blackdrake Ltd | Information & communication | 2026 |
| Blackshire ASP Ltd | Information & communication | 2006 |
| Blackstock Farm Company Limited | Wholesale & retail | 2005 |
| Blakes Meats Limited | Wholesale & retail | 2007 |
| Blanshard Holdings Limited | Other services | 1989 |
| Blochouse Limited | Construction | 2013 |
| Block & Property Management Solutions Limited | Administrative & support | 2012 |
| Blount Aerials Limited | Construction | 1997 |
| Blue Atom Consulting Limited | Professional & scientific | 2015 |
| Blue Bear Associates Limited | Wholesale & retail | 2008 |
| Blue Lemon Health & Safety Limited | Health & social care | 2013 |
| Blue Peak Ventures Limited | Real estate | 2025 |
| Bluebell Wood Lodging Ltd | Hospitality | 2023 |
| Bluebells Holdings Limited | Financial services | 2026 |
| Bluebook Partners Ltd | Administrative & support | 2016 |
| Blueprint Custom Clothing Limited | Manufacturing | 2001 |
| Blueprint Leisure Limited | Manufacturing | 1989 |
| Blush Beauty Room Limited | Administrative & support | 2017 |
| Blync LDN Limited | Wholesale & retail | 2021 |
| Bmhj Holdings Ltd | Financial services | 2024 |
| BN Living Limited | Real estate | 2016 |
| Bobedjem Limited | Wholesale & retail | 2019 |
| Bodyphyx Ltd | Wholesale & retail | 2026 |
| Bodyworks XTC Limited | Other services | 2008 |
| Bolton Buildings Holdings Limited | Financial services | 2019 |
| Bolton Buildings Limited | Construction | 2002 |
| Bolton Urology LLP | | 2023 |
| Bond Associates Building Surveyors Limited | Administrative & support | 2008 |
| Bonvendre Ltd | Wholesale & retail | 2018 |
| Bonzer UK Limited | Manufacturing | 2010 |
| Boship Dormant Ltd | Wholesale & retail | 2013 |
| Box 9 Design Limited | Professional & scientific | 2010 |
| Box Flooring Limited | Construction | 1997 |
| Boxed Freeze Limited | Manufacturing | 2015 |
| Boyziestoys Ltd | Wholesale & retail | 2024 |
| BPM Building and Plumbing Ltd | Construction | 2020 |
| Braden Timber Structures Ltd | Construction | 2020 |
| Bradleys Contractors Limited | Construction | 2015 |
| Bradshaw Close Management Limited | Households | 2024 |
| Brand Eighty Three Limited | Professional & scientific | 2019 |
| Brave at Night Ltd | Information & communication | 2015 |
| Brave Co Sales and Marketing Ltd | Wholesale & retail | 2025 |
| Braygreen Investments Limited | Other services | 2023 |
| Brenton Blue Studio Limited | Professional & scientific | 2013 |
| Bright Develop EB Limited | Construction | 2016 |
| Bright Develop Holdings Ltd | Real estate | 2019 |