| B3 FAM Ltd | Construction | 2018 |
| B3 Networks Ltd | Information & communication | 2026 |
| B3 Supplements Limited | Manufacturing | 2019 |
| B3B Limited | Other services | 2020 |
| B3CLEANN Limited | Construction | 2026 |
| B4 Wear Limited | Wholesale & retail | 2026 |
| B4BEAST Limited | Wholesale & retail | 2025 |
| B4BEER Ltd | Wholesale & retail | 2025 |
| B4BEST Limited | Wholesale & retail | 2025 |
| B4BMCR.ORG Community Interest Company | Education | 2023 |
| B58 Ltd | Wholesale & retail | 2026 |
| B7 151 Nominees Limited | Financial services | 2012 |
| B7 Investments II Limited | Extraterritorial | 2015 |
| B7 Ventures Limited | Professional & scientific | 2004 |
| B70 Composites Ltd | Manufacturing | 2022 |
| B737 Enginering Limited | Manufacturing | 2021 |
| B7STORE Ltd | Wholesale & retail | 2024 |
| B8RE Ltd | Real estate | 2015 |
| BA Aesthetics Ltd | Health & social care | 2014 |
| BA Care & Services Ltd | Health & social care | 2026 |
| BA Engineering and General Services Ltd | Professional & scientific | 2016 |
| BA Financial Group Ltd | Professional & scientific | 2020 |
| BA Lodge Ltd | Hospitality | 2022 |
| BA Sales Ltd | Wholesale & retail | 2024 |
| BA Security Limited | Administrative & support | 2025 |
| BA Smart Homes Ltd | Construction | 2009 |
| BA Smile Group Ltd | Health & social care | 2024 |
| BA Supply Company Limited | Wholesale & retail | 2025 |
| BA UK Transports Ltd | Transport & logistics | 2018 |
| Ba&Cl Ltd | Wholesale & retail | 2017 |
| Ba-Hurmuz and Partners for Trading Ltd | Wholesale & retail | 2025 |
| BA68 Ltd | Extraterritorial | 2023 |
| BAA Pharma Ltd | Wholesale & retail | 2021 |
| Baaboud UK Ltd | Wholesale & retail | 2025 |
| Baan Phad Thai Limited | Hospitality | 2016 |
| Baara Trading Ltd | Wholesale & retail | 2021 |
| Baas Model Ltd | Wholesale & retail | 2020 |
| Baasbah Enterprise Ltd | Information & communication | 2016 |
| BAB Al-Yemen Restaurant Ltd | Hospitality | 2025 |
| Baba Construction Services Limited | Construction | 2024 |
| Baba Food Processing Company Limited | Wholesale & retail | 2024 |
| Baba JI Properties Ltd | Real estate | 2024 |
| Baba Labs Limited | Other services | 2018 |
| Baba Property Ltd | Real estate | 2018 |
| Baba Traders Ltd | Wholesale & retail | 2026 |
| Baba's Convenience Store Ltd | Wholesale & retail | 2020 |
| Babaca Ltd | Manufacturing | 2025 |
| Babajide Healthcare Ltd | Health & social care | 2018 |
| Babakayo Ltd | Wholesale & retail | 2022 |
| Babar Enterprise Ltd | Transport & logistics | 2022 |
| Babasalyee Ltd | Information & communication | 2025 |
| Babbage Consulting Ltd | Information & communication | 2026 |
| Babbling Babies Ltd | Other services | 2024 |
| Babc Ltd | Wholesale & retail | 2004 |
| Babcock DS 2019 Limited | Professional & scientific | 1975 |
| Babcock Management 2019 Limited | Professional & scientific | 1998 |
| Babeguy Ltd | Manufacturing | 2025 |
| Babel Catering Limited | Hospitality | 2023 |
| Babella PAY Limited | Administrative & support | 2023 |
| Babez Manchester Limited | Wholesale & retail | 2022 |
| Babji Ltd | Professional & scientific | 2023 |
| Bablie London Ltd | Manufacturing | 2025 |
| Babocush Limited | Wholesale & retail | 2017 |
| Baboon Juice Limited | Hospitality | 2024 |
| Babor Cosmetics Limited | Wholesale & retail | 2001 |
| Babs Motion Pictures Ltd | Information & communication | 2025 |
| Babtrea Limited | Health & social care | 2014 |
| Babuchi Flavours Ltd | Hospitality | 2024 |
| Babur Ltd | Hospitality | 2020 |
| Babwilms Aviation Services Limited | Professional & scientific | 2017 |
| Baby Bear MCR Ltd | Health & social care | 2025 |
| Baby Bird Developments Limited | Real estate | 2020 |
| Baby Einstein Toys Ltd | Wholesale & retail | 2025 |
| Baby Gift Ltd | Wholesale & retail | 2026 |
| Baby Mayhem Ltd | Manufacturing | 2025 |
| Baby Moments Group Limited | Health & social care | 2026 |
| Baby Moon Toys Ltd | Wholesale & retail | 2025 |
| Baby PB Limited | Information & communication | 2015 |
| Babydove Concepts Limited | Other services | 2017 |
| Babylon Constructers Limited | Extraterritorial | 2024 |
| Babylon Express Ltd | Hospitality | 2025 |
| Babylon House (Manchester) Limited | Hospitality | 2019 |
| Babylon Manchester Ltd | Hospitality | 2022 |
| Babywonders Ltd | Wholesale & retail | 2025 |
| Babyya U.K. Limited | Wholesale & retail | 2012 |
| BAC (Accountants) MCR Ltd | Professional & scientific | 2021 |
| Bac-A-Yard 2 Limited | Hospitality | 2024 |
| Bacca Shop Limited | Wholesale & retail | 2010 |
| Bacch Ltd | Hospitality | 2019 |
| Bacch Trading Ltd | Hospitality | 2019 |
| Bacchtib Ltd | Other services | 2026 |
| Bacchus Solutions Limited | Other services | 2013 |
| Bachd Ltd | Hospitality | 2021 |
| Bachd Trading Limited | Hospitality | 2021 |
| Bachmann Port Services Limited | Administrative & support | 2011 |
| Bachmann Recruitment Limited | Administrative & support | 2002 |
| Bachmann Training Limited | Education | 2014 |
| Back a Yard Caribbean Cuisine Ltd | Hospitality | 2023 |
| Back a Yard Ltd | Manufacturing | 2020 |
| Back in a MOW Ltd | Administrative & support | 2026 |