| Beehive Care CIC | Health & social care | 2017 |
| Beeline HR Limited | Professional & scientific | 2017 |
| Beesley's Outfitters Limited | Construction | 1972 |
| Behind the White Lines Ltd | Health & social care | 2023 |
| BEK Diagnostics Ltd | Professional & scientific | 2025 |
| Bekep Development Limited | Construction | 2019 |
| Bekep Limited | Real estate | 2017 |
| Bekumo Ltd | Information & communication | 2013 |
| Belal Khalid Consulting Ltd | Health & social care | 2018 |
| Believe My Hype Coaching Limited | Other services | 2020 |
| Believe My Supplements Ltd | Health & social care | 2022 |
| Bell Court Residents Management Company Limited | Households | 2012 |
| Bella Executive Solutions Limited | Other services | 2024 |
| Bellenote Limited | Wholesale & retail | 2025 |
| Bellwethers Consulting Ltd | Information & communication | 2009 |
| Belush Erick Ltd | Wholesale & retail | 2020 |
| Belvedere House (Weybridge) Management Company Limited | Real estate | 2001 |
| Belvedere House Freehold Limited | Real estate | 2005 |
| Benardout Corporation Limited | Wholesale & retail | 2015 |
| Benbees Property Services Limited | Households | 2022 |
| Benchmark Leasing Limited | Other services | 1999 |
| Bengal Provisions Limited | Wholesale & retail | 2026 |
| Beni Developments Ltd | Real estate | 2025 |
| Berkley Clark Ltd | Professional & scientific | 2024 |
| Berks & Bucks Events Collective CIC | Arts & recreation | 2024 |
| Berkshire 24/7 Security Services Ltd | Administrative & support | 2023 |
| Berkshire Builders Ltd | Construction | 2017 |
| Berkshire Chauffeurs Ltd | Transport & logistics | 2023 |
| Berkshire Consultancy Services Ltd | Other services | 2021 |
| Berkshire Gardening and Design Company Limited | Administrative & support | 2010 |
| Berkshire House Managment Company Limited | Households | 2026 |
| Berkshire Medical and Imaging Centre Ltd | Health & social care | 2014 |
| Berkshire Nephrology Limited | Professional & scientific | 2019 |
| Berkshire Premier Limited | Real estate | 2002 |
| Berkshire Suites Ltd | Real estate | 2021 |
| Berkshire Talent Partnership Limited | Administrative & support | 2023 |
| Berkshire Townhouse Limited | Real estate | 2024 |
| Berkshire Vehicle Group Ltd | Wholesale & retail | 2026 |
| Berkshire Vintners Limited | Wholesale & retail | 2024 |
| Berkshire Water Leak Detection Limited | Other services | 2023 |
| Bernardo Consultancy Limited | Professional & scientific | 2019 |
| Berrington UK | Administrative & support | 1996 |
| Berry Marketing Limited | Wholesale & retail | 2017 |
| Berry Medical Solutions Limited | Health & social care | 2009 |
| Bertie and the Ballerina Limited | Information & communication | 2024 |
| Bessica Limited | Information & communication | 2019 |
| Best Save Food and Wine Ltd | Wholesale & retail | 2023 |
| Betsalel Consultants Limited | Professional & scientific | 2019 |
| Better Rentals Ltd | Real estate | 2025 |
| Beyond Marketing UK Ltd | Professional & scientific | 2016 |
| Beyond Number Five Limited | Information & communication | 2022 |
| BH Sets & Decor Limited | Construction | 2025 |
| BH Tattoo Limited | Other services | 2022 |
| Bhagwan Shree Lakshmi Narayan Dham (UK) | Other services | 2005 |
| BI Reporting Limited | Other services | 2007 |
| Bial Pharma UK Limited | Wholesale & retail | 2016 |
| Bifolco Matty Limited | Other services | 2018 |
| Big Bang Consulting Limited | Professional & scientific | 2012 |
| Big BEN Tower Hong Kong Ltd | Other services | 2017 |
| Big BEN Tower Ltd | Extraterritorial | 2020 |
| Big Digit Ltd | Information & communication | 2019 |
| Big League Ltd | Professional & scientific | 2025 |
| Big Outsource Limited | Hospitality | 2018 |
| Bigbash Tradings Ltd | Wholesale & retail | 2020 |
| Bildoo Limited | Administrative & support | 2018 |
| Billingbear Enterprises Limited | Administrative & support | 2000 |
| Billings & Edmonds (2006) Limited | Wholesale & retail | 2006 |
| Bimba Property Ltd | Real estate | 2020 |
| Binfield Park Management Ltd | Households | 2020 |
| Binoy Indian Ltd | Hospitality | 2018 |
| BIO Syntax London Ltd | Wholesale & retail | 2020 |
| Biohacking by Jessey Limited | Other services | 2026 |
| Biova Health Limited | Professional & scientific | 2023 |
| Biovolt Technologies Ltd | Professional & scientific | 2017 |
| Biraj Nakarja Limited | Professional & scientific | 2021 |
| Birch Hill Developments Limited | Construction | 2015 |
| Bishopsdale Limited | Information & communication | 2015 |
| Bkpal Corporation Ltd | Real estate | 2021 |
| Black & Foreign Ltd | Arts & recreation | 2025 |
| Black Circus Models Ltd | Professional & scientific | 2025 |
| Black Diamond Consultancy Limited | Real estate | 2010 |
| Black Duck Resources Limited | Professional & scientific | 2018 |
| Black EGG Studio Ltd | Information & communication | 2018 |
| Black FOX Products Ltd | Manufacturing | 2016 |
| Black Gold Traders Ltd | Wholesale & retail | 2020 |
| Black Panther Dons Community Football Club and Academy Limited | Arts & recreation | 2022 |
| Black Real Estate Ltd | Real estate | 2023 |
| Black Royale Chauffeurs Ltd | Transport & logistics | 2025 |
| Blackblaze Global Ltd | Wholesale & retail | 2017 |
| Blacklemon UK Ltd | Information & communication | 2015 |
| Blackstone Global Logistics Limited | Transport & logistics | 2025 |
| Blanchard Private Limited | Information & communication | 2025 |
| BLC Sports Ltd | Professional & scientific | 2017 |
| Bleaves Limited | Professional & scientific | 2018 |
| Blood Holdings Limited | Financial services | 2019 |
| Bloomii Ltd | Health & social care | 2020 |
| Blossom Tree Marketing Limited | Professional & scientific | 2016 |
| Blossom Works Limited | Households | 2025 |
| Blue Condor Ltd | Professional & scientific | 2023 |
| Blue DOT Solutions Limited | Real estate | 2012 |