| Bespoke Developments (Kent) Limited | Construction | 2013 |
| Bespoke Paving & Landscapes Limited | Administrative & support | 2024 |
| Best Concept Ltd | Real estate | 2023 |
| Best Mediums Limited | Extraterritorial | 2009 |
| Best of Dany Ltd | Transport & logistics | 2025 |
| Bestvenue.Com Ltd | Extraterritorial | 2006 |
| Betah Solutions Limited | Real estate | 2021 |
| Beth Childminding Services Limited | Education | 2025 |
| Beth J Limited | Health & social care | 2018 |
| Bethy Childminding Services Limited | Health & social care | 2015 |
| Betsham Road Management Limited | Households | 1993 |
| Better Days Recruitment Limited | Administrative & support | 2017 |
| Better Golf Performance Limited | Arts & recreation | 2010 |
| Betterfly Agency Ltd | Information & communication | 2021 |
| Bexon Properties Ltd | Real estate | 2022 |
| BG Funding Limited | Real estate | 1986 |
| BGS Carpentry Ltd | Construction | 2025 |
| BH Accountancy and Bookkeeping Limited | Professional & scientific | 2020 |
| BH Property Group Ltd | Real estate | 2024 |
| BHO Fire & Security Ltd | Professional & scientific | 2025 |
| Bhtc Properties Limited | Real estate | 2020 |
| Bianca Transport Ltd | Transport & logistics | 2025 |
| Biant Investments Limited | Real estate | 2013 |
| Bickley Property Maintenance Services Ltd | Construction | 2022 |
| Bicknor Estates Limited | Households | 1998 |
| Big & Little Transport Ltd | Transport & logistics | 2023 |
| Big BEE Media Ltd | Information & communication | 2014 |
| Big Numbers Property Limited | Real estate | 2023 |
| Big Trading World Ltd | Extraterritorial | 2025 |
| Big Twin Parts Ltd | Wholesale & retail | 2023 |
| Bigball Rally Ltd | Administrative & support | 2016 |
| Bigbosscyka Ltd | Wholesale & retail | 2020 |
| Biggie Properties Limited | Real estate | 2023 |
| Bigstone (Management Company) Limited | Households | 2003 |
| Bild Interiors Limited | Construction | 2021 |
| Biltmore Associates Limited | Real estate | 1999 |
| Binary Crafts Limited | Information & communication | 2018 |
| Birch Tree Studios Ltd | Other services | 2019 |
| Birchalls the Riding Shop Limited | Extraterritorial | 2003 |
| Bisoyetutu Ltd Limited | Health & social care | 2016 |
| BJC Project Controls Ltd | Construction | 2026 |
| Black Crow Books Ltd | Information & communication | 2024 |
| Black Crow Ltd | Professional & scientific | 2023 |
| Black Market Group Limited | Professional & scientific | 1990 |
| Black Market London Limited | Arts & recreation | 2009 |
| Blackadee Entertainment Limited | Wholesale & retail | 2022 |
| Blackbird Farming Limited | Agriculture & fishing | 2019 |
| Blacktail Holdings Ltd | Agriculture & fishing | 2020 |
| Blackverse Group Ltd | Real estate | 2025 |
| Blackverse Ltd | Construction | 2020 |
| Blank Canvas Vehicle Graphics Ltd | Manufacturing | 2013 |
| Blaze Tattoo Limited | Administrative & support | 2010 |
| Blenwood Limited | Administrative & support | 2002 |
| Blicket Ltd | Information & communication | 2020 |
| Bliss-B Ltd | Information & communication | 2022 |
| Blissful Ltd | Administrative & support | 2024 |
| Blon Tech Ltd | Information & communication | 2022 |
| Blossom Accounting & Advisory Limited | Professional & scientific | 2026 |
| Blossom Event Creations Ltd | Hospitality | 2024 |
| Blossoms (Group Holdings) Limited | Financial services | 2015 |
| Blossoms Care Services Limited | Health & social care | 2008 |
| BLU Revolution Limited | Agriculture & fishing | 2018 |
| Blue DOT Stays Ltd | Real estate | 2019 |
| Blue Fountain Security Systems Limited | Information & communication | 2019 |
| Blue Logistics Limited | Transport & logistics | 2022 |
| Blue Panel Ltd | Wholesale & retail | 2021 |
| Blue Platinum Limited | Real estate | 2008 |
| Blue Skyline Investments Limited | Real estate | 2021 |
| Blue Stone Retail Ltd | Wholesale & retail | 2026 |
| Bluebird Recruitment Services Limited | Administrative & support | 2021 |
| Blueheath Services Ltd | Health & social care | 2025 |
| Blueprint Tax and Advisory Ltd | Professional & scientific | 2025 |
| Bluewave Innovation Group Ltd | Manufacturing | 2025 |
| Blundell Property Ltd | Real estate | 2015 |
| Blundy Holdings Limited | Financial services | 2022 |
| Blundy's Property Management Limited | Real estate | 2022 |
| Blynk Solutions Ltd | Administrative & support | 2017 |
| BM Property Developments Ltd | Construction | 2024 |
| Bmac Studio Architecture and Project Management Limited | Professional & scientific | 2016 |
| BMR45 Ltd | Wholesale & retail | 2019 |
| BNC Engineering Services South East Limited | Manufacturing | 2010 |
| BOB & Emma Estate Limited | Real estate | 2025 |
| BOD - ENI Consult Ltd. | Professional & scientific | 2011 |
| Bodycare Health and Fitness Limited | Arts & recreation | 2003 |
| Bogie Engineering Limited | Manufacturing | 2013 |
| Bolthay Limited | Financial services | 2024 |
| Book a Mechanic Online Ltd | Wholesale & retail | 2025 |
| Boost Fulfilment Limited | Transport & logistics | 2016 |
| Boost Property Management Limited | Real estate | 2022 |
| Boots and Care Limited | Real estate | 2023 |
| Boots and Property Limited | Real estate | 2024 |
| Boots on Adventures Ltd | Arts & recreation | 2021 |
| Borden Building Services Ltd | Construction | 2021 |
| Borden Grammar School Trust | Education | 2011 |
| Borden Lane VET Limited | Professional & scientific | 2004 |
| Borden Sport Limited | Arts & recreation | 1999 |
| Bounceability Limited | Arts & recreation | 1999 |
| Boundless Canvas Ltd | Information & communication | 2025 |
| Bourne 2 Blast Ltd | Administrative & support | 2024 |
| Bourne Carpentry Limited | Construction | 2007 |