| Bergholt Investments Ltd | Real estate | 2024 |
| Berk Wilton Ltd | Hospitality | 2018 |
| Berkeley Bate (Salisbury) Limited | Other services | 2020 |
| Berkeley Bate Outsourcing LLP | | 2014 |
| Berkeley GRP Products Limited | Manufacturing | 2019 |
| Berkeley Mews Residents Association (Acton) Limited | Households | 1988 |
| Berkshire Plant Hire Limited | Administrative & support | 2017 |
| Berrington JAY Ltd | Health & social care | 2012 |
| Berrow Court Management Company Limited | Households | 2009 |
| Berwick ST John Country Fayre Limited | Arts & recreation | 2008 |
| Beryluv Ltd | Health & social care | 2024 |
| Berzann Ltd | Hospitality | 2018 |
| Bespoke Garden Spaces Limited | Wholesale & retail | 2021 |
| Bespoke Glass and Repairs Limited | Construction | 2017 |
| Bespoke Plumbing and Bathrooms Ltd | Construction | 2023 |
| Bessant Investments Limited | Financial services | 2017 |
| Bessant Properties Limited | Real estate | 2009 |
| Best Property Holdings Limited | Real estate | 2017 |
| Bestival Limited | Arts & recreation | 2004 |
| Bethany Cooper Productions Ltd | Arts & recreation | 2020 |
| Bethwin RTM Company Limited | Households | 2010 |
| Better Body Basics Ltd | Information & communication | 2026 |
| Better Days Gifts Ltd | Wholesale & retail | 2026 |
| Better Futures for Gamblers C.I.C. | Health & social care | 2015 |
| Better Green Ltd | Professional & scientific | 2016 |
| Bettycom Ltd | Wholesale & retail | 2023 |
| Beyond the Line Limited | Information & communication | 1996 |
| Bfbs (Consultants) Limited | Professional & scientific | 1999 |
| Bfe-Uk Limited | Wholesale & retail | 2014 |
| BFI Buildings Ltd | Construction | 2013 |
| BFS Consultancy Limited | Administrative & support | 2013 |
| Bh.Qms Ltd | Construction | 1997 |
| Bharat Ltd | Construction | 2025 |
| Bhavic Limited | Information & communication | 2019 |
| BHE Marketing Limited | Extraterritorial | 2022 |
| Bibio Consulting Limited | Professional & scientific | 2021 |
| Bidassoa Ltd | Professional & scientific | 2021 |
| Big Bloomers Ltd | Agriculture & fishing | 2026 |
| Big Jugs Ltd | Administrative & support | 2022 |
| Big Red Climbing Ltd | Education | 2023 |
| Big Smart Ideas Ltd | Wholesale & retail | 2006 |
| Big Spender Limited | Extraterritorial | 2003 |
| Big Stay Limited | Administrative & support | 2012 |
| Big Teddy Films Limited | Information & communication | 2017 |
| Bigfa Limited | Health & social care | 2025 |
| Bijou Boxes Ltd | Wholesale & retail | 2021 |
| BIKE2BIKE Limited | Wholesale & retail | 2019 |
| Bikebins.Com Limited | Real estate | 2004 |
| Bilal Gazi Ltd | Other services | 2024 |
| Billingham Anaesthetic Services Ltd | Health & social care | 2025 |
| Bills Bikes Ltd | Wholesale & retail | 2026 |
| Billy Hughes Photography Ltd | Professional & scientific | 2024 |
| Bimi Global Limited | Wholesale & retail | 2024 |
| BIO Health Hackers Ltd | Health & social care | 2025 |
| Bioprojet UK Limited | Manufacturing | 2000 |
| Bioresources Limited | Agriculture & fishing | 2019 |
| Biosurv International Ltd | Professional & scientific | 2022 |
| Biotech Energy Group Limited | Wholesale & retail | 2016 |
| Birch Architects Ltd | Professional & scientific | 2020 |
| Birch Construction Limited | Construction | 2002 |
| Birch House (Verwood) Management Company Limited | Households | 2024 |
| Birch Lane (Sandleheath) Management Limited | Real estate | 2021 |
| Birch Park Huntington York Management Company Limited | Households | 2007 |
| Bird and Carter Limited | Wholesale & retail | 2020 |
| Birdwood Consultancy Ltd | Professional & scientific | 2023 |
| Biri Trading UK Ltd | Wholesale & retail | 2021 |
| Bishop & Smith Limited | Construction | 2015 |
| Bishop Wordsworth's Church of England Grammar School | Education | 2011 |
| Bishops Keep Block B Management Limited | Households | 2008 |
| Bishops Keep Block C Management Limited | Households | 2009 |
| Bisi Creative Limited | Professional & scientific | 2011 |
| Bison Concrete and Civils Limited | Construction | 2023 |
| Bison Waste Ltd | Water & waste | 2018 |
| Bitlevel Limited | Professional & scientific | 2012 |
| Bitterne Park Limited | Real estate | 1996 |
| Bizgive Limited | Information & communication | 2016 |
| BJ Medical Ltd | Health & social care | 2019 |
| Bjmass Ltd | Financial services | 2020 |
| BK Primary Care Ltd | Financial services | 2025 |
| Bkwbarsandevents Group Ltd | Hospitality | 2025 |
| Black Dog Aviation Limited | Professional & scientific | 2017 |
| Black Swan Futures Ltd | Professional & scientific | 2012 |
| Black TOR Brewery Ltd | Manufacturing | 2013 |
| Blackdown Heights (Crimchard) Management Company Limited | Households | 2021 |
| Blacklight Telecommunications Limited | Information & communication | 2010 |
| Blackmore Museum Management Company Limited | Households | 2015 |
| Blackthorn Meadows Residents Management Company Limited | Households | 2018 |
| Blade Automotive Group Limited | Financial services | 2024 |
| Blade Motor Cycles Holdings Limited | Financial services | 2015 |
| Blade Motor Cycles Limited | Wholesale & retail | 2003 |
| Blade Motor Group Holdings Limited | Financial services | 2015 |
| Blade Motor Group Limited | Wholesale & retail | 1995 |
| Blakcro Limited | Construction | 2023 |
| Blake Dark Associates Ltd | Professional & scientific | 2023 |
| Blakeley Construction Profiles Ltd | Wholesale & retail | 2019 |
| Blakeley Holdings Limited | Financial services | 2026 |
| Blandridge Consultants Ltd | Administrative & support | 2016 |
| Blavin Limited | Professional & scientific | 2025 |
| Blazer Line Limited | Manufacturing | 2010 |
| Blazing Spearhead Ltd | Transport & logistics | 2024 |