| Bexley Homes Investments Ltd | Real estate | 2022 |
| Bexley Homes Limited | Construction | 2018 |
| Bexley Park Sports & Social Club Limited | Arts & recreation | 2002 |
| Bexley Plumbing UK Ltd | Construction | 2012 |
| Bexley Restaurants Limited | Hospitality | 2013 |
| Bexley Tigers Limited | Arts & recreation | 2024 |
| Beynur Barbers Limited | Other services | 2017 |
| Beyond Bounce Ltd | Arts & recreation | 2018 |
| Beyond Digital IT Ltd | Information & communication | 2016 |
| Beyondpay Ltd | Administrative & support | 2025 |
| BF Site Services Limited | Construction | 2022 |
| BFC (UK) Limited | Wholesale & retail | 2009 |
| BFG Group Ltd | Construction | 2023 |
| BFS Properties (S.E.) Limited | Real estate | 1999 |
| BGC British Georgian Company Ltd | Hospitality | 2017 |
| BH MED Services Ltd | Hospitality | 2025 |
| Bharat Estates Limited | Real estate | 2022 |
| Bharath Book Store Ltd | Wholesale & retail | 2024 |
| Bheen Limited | Hospitality | 2016 |
| Bhides Limited | Health & social care | 2019 |
| Bhides Properties Ltd | Real estate | 2023 |
| BHK Develope Limited | Real estate | 2024 |
| BHP Maintenance Ltd | Real estate | 2017 |
| Bibi Mart Ltd | Wholesale & retail | 2025 |
| Bible Life Christian Centre Limited | Education | 2009 |
| Big B Properties Ltd | Real estate | 2022 |
| Big Building & Mechanical Ltd | Construction | 2013 |
| Big COQ Limited | Hospitality | 2023 |
| Big Friendly Car Sales Ltd | Wholesale & retail | 2025 |
| Big Friendly Garage Limited | Wholesale & retail | 2023 |
| Big FUN UK Limited | Manufacturing | 2017 |
| Big J S' Biltong Bar Ltd | Hospitality | 2026 |
| Big Legacy Dry-Lining Limited | Construction | 2025 |
| Big Money Ltd | Extraterritorial | 2006 |
| Big Skies Travel Limited | Administrative & support | 2024 |
| Biggin Hill Sushi Ltd | Wholesale & retail | 2024 |
| Bike Alert PLC | Wholesale & retail | 1989 |
| Bilboco Limited | Information & communication | 2022 |
| BIN Saif Ltd | Wholesale & retail | 2025 |
| Bincode Ltd | Information & communication | 2013 |
| Binnie Holding Company Ltd | Financial services | 2025 |
| Biomanagement Systems Limited | Financial services | 2018 |
| Bionanotech Consultants Ltd | Professional & scientific | 2023 |
| Biopharm Search LLP | | 2011 |
| Birchwood Gastroenterology Limited | Health & social care | 2019 |
| Birchwood Gourmet Ltd | Hospitality | 2020 |
| Birchwood Pharma Ltd | Manufacturing | 2011 |
| Bird in Hand Kent Ltd | Hospitality | 2024 |
| Birring Consultancy Services Ltd | Professional & scientific | 2014 |
| Birring Medical Services Limited | Real estate | 2016 |
| Birtley House (Kent) Limited | Education | 2009 |
| Bishwa Shahittya Kendra Limited | Education | 2002 |
| Bisioorganics Limited | Wholesale & retail | 2020 |
| Bisma Foods Ltd | Hospitality | 2020 |
| Bisron Limited | Wholesale & retail | 2011 |
| Bite ME Catering LLP | | 2006 |
| Bits and Pieces Entertainment Limited | Arts & recreation | 2022 |
| Bizera Limited | Real estate | 2024 |
| Bizesy Ltd | Wholesale & retail | 2021 |
| Bizniz Point Dartford Lease Limited | Real estate | 2011 |
| Bizniz Point Dartford Limited | Real estate | 2011 |
| Bizniz Point Limited | Administrative & support | 2011 |
| Bizniz Point Stratford Lease Limited | Real estate | 2011 |
| Bizniz Point Stratford Limited | Real estate | 2011 |
| Bizota Ltd | Financial services | 2024 |
| Bizzle Operations Management Limited | Administrative & support | 2018 |
| BJC Kent Ltd | Real estate | 2020 |
| Bjja Consulting Limited | Professional & scientific | 2014 |
| BJK Shop Equipment Limited | Construction | 2007 |
| BJM Heating Limited | Construction | 2010 |
| BK Childcare Limited | Health & social care | 2016 |
| BK Luxe Care &Consultancy Limited | Health & social care | 2025 |
| BL Creative Construction Ltd | Construction | 2026 |
| BL Global Ltd | Wholesale & retail | 2025 |
| Black Apprentice Network (Current) C.I.C. | Administrative & support | 2025 |
| Black CAB Tours of London Ltd | Administrative & support | 2023 |
| Black Entrepreneurs International CIC | Administrative & support | 2024 |
| Black in Sport Ltd | Administrative & support | 2023 |
| Black Pine Design Limited | Professional & scientific | 2021 |
| Black Star Global Assets Limited | Construction | 2022 |
| Black Tulip Academy Limited | Information & communication | 2021 |
| Blackbone Limited | Information & communication | 2007 |
| Blackfen Motorist Centre Ltd | Wholesale & retail | 2010 |
| Blackheath Interior Shutters Ltd | Wholesale & retail | 2023 |
| Blackheath Refrigeration & Air Conditioning Engineering (Brace) Limited | Manufacturing | 2011 |
| Blackpeppers BI Limited | Information & communication | 2013 |
| Blackrun RD Ltd | Professional & scientific | 2019 |
| Blackstar Plumbing Ltd | Construction | 2021 |
| Blackstonegrappling Ltd | Arts & recreation | 2025 |
| Blacksure Services Ltd | Construction | 2023 |
| Blackwell Electrical Contractors Limited | Construction | 2013 |
| Blakeney Motorsport Limited | Manufacturing | 2005 |
| Blank Canvas Studio Ltd | Health & social care | 2022 |
| Blbt Ltd | Other services | 2014 |
| Bled Car Sales Ltd | Wholesale & retail | 2024 |
| Blendbar Holdings Ltd | Hospitality | 2025 |
| Blended Edge Media Limited | Information & communication | 2020 |
| Blended Scents Ltd | Wholesale & retail | 2024 |
| Blenheim Gate Management Limited | Households | 2001 |
| Blenheim Square Properties Ltd | Real estate | 2019 |