| BM Focus Limited | Administrative & support | 2015 |
| BM Home Ground Limited | Extraterritorial | 2017 |
| BMC London Ltd | Construction | 2023 |
| BMC Pilates III Ltd | Arts & recreation | 2026 |
| BMJ Business Ltd | Wholesale & retail | 2024 |
| BMK 1A Limited | Professional & scientific | 2022 |
| Bmnz Tradings & Services Ltd | Hospitality | 2025 |
| BMP Partners Ltd | Information & communication | 2025 |
| Bmvk House of Saffron Ltd | Hospitality | 2026 |
| BN Foundation UK | Health & social care | 2025 |
| BN Properties Ltd | Real estate | 2018 |
| Bnayak Ltd | Construction | 2023 |
| BND Audits Limited | Professional & scientific | 2009 |
| Bnkm International Limited | Professional & scientific | 2024 |
| Bnova GV Ltd | Hospitality | 2016 |
| BNS Enterprises Ltd | Wholesale & retail | 2022 |
| Bob's Deli Ltd | Administrative & support | 2016 |
| Boba Bar Limited | Hospitality | 2019 |
| Boba House Ltd | Hospitality | 2022 |
| Bobby's Removals Limited | Transport & logistics | 2015 |
| Bodek Recovery Ltd | Transport & logistics | 2023 |
| Body by Sean Limited | Other services | 2018 |
| Body Rejuvenation Clinic Limited | Health & social care | 2024 |
| Body Rejuvenation Limited | Other services | 2022 |
| Body Rescue Ltd | Wholesale & retail | 2022 |
| Body Smart Cars Limited | Other services | 2021 |
| Bodywork Paint Limited | Wholesale & retail | 2023 |
| Bohemian Craft Ltd | Construction | 2015 |
| Bohos Apartments Ltd | Hospitality | 2025 |
| Boki Coffee Ltd | Hospitality | 2018 |
| Boki Coffee Roasters Limited | Wholesale & retail | 2024 |
| Boki Group Limited | Hospitality | 2016 |
| Boki Hospitality Ltd | Hospitality | 2018 |
| Boki One World Limited | Hospitality | 2020 |
| Bolt 30 Construction Ltd | Construction | 2022 |
| Boltmark Printing and Advertising Ltd | Professional & scientific | 2025 |
| Bombay Local London Ltd | Real estate | 2017 |
| Bombay Metro London Limited | Hospitality | 2017 |
| Bombay to Ahmedabad Limited | Manufacturing | 2024 |
| Bomfaier Group Ltd | Construction | 2026 |
| Bonavista Investments Limited | Real estate | 2016 |
| Bond Building and Decoration Ltd | Construction | 2019 |
| Bond Courier UK Ltd | Transport & logistics | 2026 |
| Bond Street Management Services Limited | Construction | 1978 |
| Bondedbiz Ltd | Wholesale & retail | 2026 |
| Bondmead Limited | Real estate | 1990 |
| Bongs Good Care Ltd | Health & social care | 2025 |
| Bonham Group Ltd | Information & communication | 2016 |
| Boni Trans Ltd | Transport & logistics | 2025 |
| Bonthe Consultancy Limited | Professional & scientific | 2010 |
| Book and Cook U.K Limited | Real estate | 2021 |
| Bookabot Ltd | Wholesale & retail | 2025 |
| Booking Giant Limited | Administrative & support | 2017 |
| Booking Stop Ltd | Hospitality | 2025 |
| Bookingwire Limited | Administrative & support | 2013 |
| Boomerang Lounge Ltd | Hospitality | 2019 |
| Boomi Homes UK Ltd | Real estate | 2022 |
| Booze, Drink, Runners Ltd | Wholesale & retail | 2022 |
| Bophonysse Limited | Manufacturing | 2020 |
| Bordun Ltd | Professional & scientific | 2023 |
| Borough Capital Limited | Real estate | 2024 |
| Borrowed Time Ltd | Wholesale & retail | 2024 |
| Borthe UK Limited | Wholesale & retail | 2022 |
| Bost Clinic Limited | Health & social care | 2011 |
| Bostan-E-Kabul Car Rental Ltd | Administrative & support | 2022 |
| Boston Express Enterprises Ltd | Wholesale & retail | 2016 |
| Botbrain Ltd | Wholesale & retail | 2020 |
| Bottobathrooms Ltd | Construction | 2019 |
| Boulton Hayward LLP | | 2015 |
| Bounty Road Dental Practice Limited | Health & social care | 2011 |
| Bousni Ltd | Wholesale & retail | 2024 |
| Boutique Dentalis Ltd | Health & social care | 2022 |
| Bowen Fintech Limited | Administrative & support | 2024 |
| Bower Products Limited | Manufacturing | 1979 |
| Bowl Limited | Wholesale & retail | 2021 |
| Boxed Design Ltd | Professional & scientific | 2017 |
| Boxing Baby Limited | Wholesale & retail | 2017 |
| Boxxpod Ltd | Information & communication | 2024 |
| Boyce LUX Cars Ltd | Wholesale & retail | 2018 |
| BP IT Services Ltd | Information & communication | 2025 |
| BP Law Consultancy Ltd | Professional & scientific | 2023 |
| BP Ventures Ltd | Real estate | 2015 |
| BQ Hair Dresser Ltd | Other services | 2018 |
| BR Services Europe Limited | Professional & scientific | 2019 |
| BR Sports Consultancy Ltd | Arts & recreation | 2022 |
| BR2 Enterprise Ltd | Real estate | 2025 |
| Brachesan Ltd | Administrative & support | 2018 |
| Brain 22 Ltd | Health & social care | 2022 |
| Brainy Solution and Services Ltd | Wholesale & retail | 2025 |
| Braithwaite Williams Limited | Real estate | 2022 |
| Bramham Properties Ltd | Construction | 2020 |
| Bramingham Dental Clinic Limited | Health & social care | 2010 |
| Brampton Hospitality Ltd | Hospitality | 2025 |
| Brand Secondhand Limited | Wholesale & retail | 2025 |
| Brandlift Advertising UK Ltd | Professional & scientific | 2026 |
| Brangwen Properties Limited | Real estate | 2025 |
| Braschem Commodities and Energy UK Limited | Financial services | 2024 |
| Braywick Automotive Limited | Wholesale & retail | 2014 |
| Braywick Developments Ltd | Construction | 2020 |
| Brazilian Products Limited | Hospitality | 2005 |