| Booze Outlet Limited | Real estate | 2006 |
| Booze Traders Ltd | Wholesale & retail | 2022 |
| Boozy Busters Convenience Store Ltd | Wholesale & retail | 2016 |
| Boozy Busters Store Ltd | Wholesale & retail | 2022 |
| BOR Investments Limited | Real estate | 1956 |
| Border Television Ltd | Information & communication | 2012 |
| Borderbrook Properties Ltd | Real estate | 2025 |
| Bordila Holdings Ltd | Financial services | 2023 |
| Bordila Ltd | Health & social care | 2007 |
| Bordison Memory Company Limited | Extraterritorial | 2017 |
| Boreal IT Systems Ltd | Information & communication | 2025 |
| Borealis Properties Ltd | Real estate | 2022 |
| Borealis UK Ltd | Wholesale & retail | 1978 |
| Boreb Health Care Limited | Health & social care | 2025 |
| Boris MCR Ltd | Construction | 2025 |
| Borkin Limited | Professional & scientific | 2011 |
| Borkwood Development Software Ltd | Extraterritorial | 2015 |
| Borlah Care Ltd | Health & social care | 2020 |
| Bormanis Ltd | Information & communication | 2019 |
| Born 2 Compete Limited | Education | 2024 |
| Born Enterprises Limited | Financial services | 2025 |
| Born Global Limited | Administrative & support | 2018 |
| Bornfree Group Ltd | Real estate | 2019 |
| Bornmore (Metals) Limited | Wholesale & retail | 1979 |
| Boroughs Pizza Ltd | Hospitality | 2026 |
| Borowin Ltd | Health & social care | 2025 |
| Borrans Park House Management Limited | Real estate | 2008 |
| Borsabella Trading Limited | Administrative & support | 2018 |
| Borson Limited | Financial services | 2018 |
| Borycon Ltd | Construction | 2025 |
| BOS Consulting Group Limited | Professional & scientific | 2016 |
| BOS Contracting Limited | Financial services | 2026 |
| BOS Energy Ltd | Manufacturing | 2020 |
| BOS Eyecare Limited | Health & social care | 2005 |
| BOS Global Links Limited | Wholesale & retail | 2025 |
| BOS7 Manchester Limited | Real estate | 2025 |
| BOS8 Manchester Limited | Real estate | 2026 |
| Bosab Healthcare Limited | Health & social care | 2023 |
| Bosal (U.K.) Limited | Manufacturing | 1977 |
| Bosal Care Limited | Health & social care | 2025 |
| Bosanski Ultimate Performance Ltd | Transport & logistics | 2024 |
| Bosati Ltd | Wholesale & retail | 2020 |
| Boscan Moto Ltd | Other services | 2020 |
| Boscho Healthcare Limited | Public administration | 2025 |
| Bose Medical Consultancy Services Ltd | Health & social care | 2014 |
| Boseycroft Ltd | Real estate | 2009 |
| Bosh Padel Club Ltd | Arts & recreation | 2026 |
| Bosh Properties Ltd | Real estate | 2020 |
| Bosheng Ltd | Transport & logistics | 2022 |
| Boshhh Europe Limited | Financial services | 2024 |
| Boshhh Financial Services Limited | Financial services | 2024 |
| Boshhh Fintech Ltd | Financial services | 2024 |
| Boshhh Group Limited | Financial services | 2025 |
| Boshhh Moneyapp Limited | Financial services | 2024 |
| Boshhh Telecommunications Limited | Information & communication | 2025 |
| BOSHP1 Project Services Limited | Other services | 2010 |
| Bosjjxx Cleaning Service Ltd | Administrative & support | 2025 |
| Bosma Logistic Ltd | Transport & logistics | 2024 |
| Bosmay Global Limited | Wholesale & retail | 2025 |
| Bosphorus Ltd | Other services | 2025 |
| Boss Agencies Holdings Limited | Administrative & support | 1999 |
| Boss Agencies Limited | Administrative & support | 1988 |
| Boss Barber 25 Ltd | Other services | 2025 |
| Boss Beauty Group Ltd | Other services | 2020 |
| Boss Consultants Ltd | Education | 2025 |
| Boss Direct Holdings Limited | Financial services | 2025 |
| Boss Dynamics Limited | Information & communication | 2024 |
| Boss Heat UK Ltd | Construction | 2021 |
| Boss Hotel Ltd | Hospitality | 2019 |
| Boss Jewelry Ltd | Wholesale & retail | 2025 |
| Boss Key Project Management Ltd | Construction | 2022 |
| Boss Lady's Hair Ltd | Wholesale & retail | 2019 |
| Boss MOM Journey Ltd | Wholesale & retail | 2024 |
| Boss Online Trader Ltd | Wholesale & retail | 2024 |
| Boss Realty Limited | Real estate | 2022 |
| Boss Taxi Rental Services Ltd | Wholesale & retail | 2020 |
| Boss Traders Limited | Other services | 2017 |
| Boss Trends Ltd | Wholesale & retail | 2020 |
| Bossa 71 Business Ltd | Wholesale & retail | 2026 |
| Bosse Computers Limited | Wholesale & retail | 1998 |
| Bossi Holdings Limited | Wholesale & retail | 2024 |
| Bossmans Takeaway Ltd | Hospitality | 2025 |
| Bostan Khan Enterprises Ltd | Wholesale & retail | 2026 |
| Bostan Traders Ltd | Wholesale & retail | 2025 |
| Boston Arthaus Limited | Wholesale & retail | 2021 |
| Boston BFC Ltd | Hospitality | 2026 |
| Boston Fried Chicken Ltd | Hospitality | 2018 |
| Boston NW Ltd | Hospitality | 2026 |
| Boston RE Ltd | Energy | 2013 |
| Bostonfitness Ltd | Health & social care | 2025 |
| Bosun Recruitment Limited | Administrative & support | 2019 |
| Boswell International Limited | Professional & scientific | 2021 |
| Boswell Property Services Limited | Professional & scientific | 1990 |
| BOT FIX Ltd | Manufacturing | 2026 |
| Botanical Brothers Drinks Ltd | Manufacturing | 2020 |
| Botaniva Organics Ltd | Wholesale & retail | 2025 |
| Botech Electronics Limited | Wholesale & retail | 2026 |
| Boteera for Trading Ltd | Wholesale & retail | 2026 |
| Both Barrels PR & Sponsorship Marketing Ltd | Professional & scientific | 2024 |
| Both Feet Media Limited | Professional & scientific | 2019 |