| Blink 360 Ltd | Administrative & support | 2013 |
| Blink of an EYE Ltd | Administrative & support | 2010 |
| Bliss Industrial Roofing & Cladding Limited | Construction | 2023 |
| Blockport Limited | Real estate | 1990 |
| Blomfield ST Leonards Management Company Ltd | Households | 2008 |
| Blossom Hypnotherapy Limited | Other services | 2015 |
| BLU DOT Design Limited | Construction | 2018 |
| Blue Arrow Properties Limited | Financial services | 1962 |
| Blue Box Consultancy Limited | Administrative & support | 2023 |
| Blue Chip Corporate Support Services Limited | Professional & scientific | 1998 |
| Blue Gorilla Ltd | Wholesale & retail | 2016 |
| Blue Green Markets Ltd | Administrative & support | 2015 |
| Blue House Builds Ltd | Construction | 2022 |
| Blue Ocean Performance Ltd | Administrative & support | 2016 |
| Blue Palm Coffee Limited | Hospitality | 2023 |
| Blue Pelican Consulting Limited | Administrative & support | 2017 |
| Blue Spurs Enterprises Limited | Hospitality | 2022 |
| Blue Swift Accountants Limited | Professional & scientific | 2023 |
| Blue Wren Consultants Ltd | Professional & scientific | 2022 |
| Blueberry Motorsport Ltd | Education | 2023 |
| Blueoval Ventures Limited | Wholesale & retail | 2008 |
| Blueredpurple Ltd | Information & communication | 2025 |
| BM Electrical South East Limited | Construction | 2016 |
| BMB Logistics Ltd | Transport & logistics | 2022 |
| BMC Designworks Ltd | Other services | 2023 |
| BMC Medical Limited | Health & social care | 2019 |
| BMR Construction Limited | Construction | 2013 |
| BNM Mechanical and Electrical Services Limited | Construction | 2017 |
| BNS Group Limited | Construction | 2017 |
| BOA (UK) Limited | Manufacturing | 1994 |
| BOA Style Limited | Manufacturing | 2000 |
| BOA Tool Company Ltd | Manufacturing | 2000 |
| Boba Box Limited | Wholesale & retail | 2010 |
| Bobbys Loft Ltd | Wholesale & retail | 2022 |
| Bobeh Consultancy Ltd | Professional & scientific | 2021 |
| Bodvoc Holdings Limited | Real estate | 2022 |
| Bodvoc Limited | Information & communication | 2008 |
| Body Talking Ltd | Arts & recreation | 2010 |
| Body Wellness Pilates Limited | Extraterritorial | 2019 |
| Bodycode Fitness Limited | Wholesale & retail | 2019 |
| Bogdancatalin Service Ltd | Construction | 2020 |
| Bohemia Canvas Hire Ltd | Administrative & support | 2020 |
| Bohemia Canvas Ltd | Administrative & support | 2020 |
| Bold Building Ltd | Construction | 2024 |
| Boma Investments Limited | Real estate | 2020 |
| Bombay Panda Ltd | Real estate | 2025 |
| Boocee Equine Services Ltd | Wholesale & retail | 2024 |
| Boosu Ltd | Information & communication | 2017 |
| Bopbop Studios Ltd | Information & communication | 2026 |
| Bordyke Consulting Limited | Professional & scientific | 2002 |
| Born Medical Consultancy Limited | Health & social care | 2013 |
| Bornite Limited | Professional & scientific | 2024 |
| Boro Farm Limited | Agriculture & fishing | 2014 |
| Bors Veloo Ltd | Administrative & support | 2011 |
| Bosh Property Ltd | Real estate | 2024 |
| Bostall Holdings Ltd | Other services | 2022 |
| Bostrack Limited | Professional & scientific | 2014 |
| Bottega Fine Art Ltd | Hospitality | 2025 |
| Bourne House Physiotherapy Clinic Limited | Health & social care | 2004 |
| Bourne Place House Management Company Limited | Real estate | 2000 |
| Bourne Place Wood Limited | Agriculture & fishing | 2005 |
| Bourne Valley Ltd | Hospitality | 2020 |
| Bowes Hospitality Ltd | Hospitality | 2022 |
| Bowman Coaching Solutions Ltd | Arts & recreation | 2016 |
| BOX79 Ltd | Real estate | 2020 |
| Boxcircle Limited | Professional & scientific | 2014 |
| Boxspoke Ltd | Construction | 2023 |
| Boxsquare Limited | Financial services | 2008 |
| Boxwood Homes Limited | Extraterritorial | 2014 |
| Boyle Consulting Limited | Education | 2024 |
| BPK Medical Ltd | Health & social care | 2022 |
| Bradbourne Group Riding for the Disabled Association | Arts & recreation | 2007 |
| Bradbourne Road Limited | Real estate | 2022 |
| Bradmatt Limited | Construction | 2022 |
| Brain Machine Hygeia Limited | Information & communication | 2025 |
| Brain Train Ltd | Health & social care | 2017 |
| Brait Limited | Professional & scientific | 2012 |
| Bramko Limited | Construction | 2005 |
| Branch Digital Ltd | Information & communication | 2026 |
| Brand Building Solutions Limited | Wholesale & retail | 2017 |
| Brand Display Limited | Manufacturing | 2015 |
| Brandfold High Performance Limited | Wholesale & retail | 2021 |
| Braybrook Electrical Limited | Construction | 2026 |
| Breeze Trustees Limited | Financial services | 2025 |
| Bren Building & Renovations Ltd | Construction | 2020 |
| Brenchley Conversions Ltd | Manufacturing | 2018 |
| Brenchley Dental Limited | Health & social care | 2024 |
| Brenchley Developments Ltd. | Construction | 2001 |
| Brenchley Electrical Services Ltd | Construction | 2014 |
| Brenchley Homes Ltd. | Construction | 2004 |
| Brenchley MOT Station Ltd | Wholesale & retail | 2024 |
| Brenchley Properties Ltd. | Construction | 1996 |
| Brenton Partners Limited | Administrative & support | 2015 |
| Brewson Tech LLP | | 2025 |
| Brewster Investments Ltd | Real estate | 2021 |
| Brick Lane Bagelz Canary Wharf Ltd | Hospitality | 2024 |
| Bridge Deli Kent Limited | Wholesale & retail | 2025 |
| Bridge Flexi School Ltd | Education | 2021 |
| Bridgehurst Holdings Limited | Administrative & support | 2001 |
| Brigade Fitness UK Ltd | Education | 2019 |