| Black Red Media Ltd | Professional & scientific | 2022 |
| Blackbox Capital Limited | Administrative & support | 2018 |
| Blacksocks Limited | Wholesale & retail | 2011 |
| Blakeney Hall Residents Association Limited | Households | 1990 |
| Blakewood Silvermere Ltd | Real estate | 2021 |
| Blamer Pharma Co., Ltd | Manufacturing | 2020 |
| Blanc Nails Ltd | Other services | 2021 |
| Blandbeck RTM Limited | Real estate | 2023 |
| Bldc-Motor Co., Ltd | Wholesale & retail | 2020 |
| Blenheim House Management (Beckenham) Limited | Households | 2002 |
| Bleruskin UK Personal Care Products Co., Ltd | Extraterritorial | 2026 |
| Bless Apparel Co., Ltd | Extraterritorial | 2015 |
| Blessed & Saved Ltd | Hospitality | 2026 |
| Bleu Citron Limited | Administrative & support | 2014 |
| Blind Squirrel Relationship Management Limited | Financial services | 2016 |
| Blinke Media Limited | Professional & scientific | 2025 |
| BLL Supply Chain Co., Ltd | Extraterritorial | 2014 |
| Bloc. Padel Ltd | Arts & recreation | 2026 |
| Blockverse Limited | Information & communication | 2021 |
| Bloom Botanicals Limited | Professional & scientific | 2016 |
| Blooming Trading Group Ltd | Extraterritorial | 2020 |
| Bloomingdg Care Limited | Wholesale & retail | 2025 |
| Blossom Path Education Ltd | Wholesale & retail | 2025 |
| Blossoms Vision Technology Limited | Manufacturing | 2024 |
| BLR Haulage Ltd | Transport & logistics | 2024 |
| BLU Lifestyle Photography Limited | Other services | 2017 |
| Blue Anchor Lane Limited | Extraterritorial | 2013 |
| Blue Box Hire Limited | Administrative & support | 2017 |
| Blue FOX Systems Limited | Information & communication | 2011 |
| Blue Joy Technology Co., Ltd | Manufacturing | 2026 |
| Blue Mountain International (UK) Co., Ltd | Extraterritorial | 2017 |
| Blue Neil Limited | Arts & recreation | 2003 |
| Blue Ocean Marine Service Co., Ltd | Wholesale & retail | 2013 |
| Blue Shark Fixings Co., Ltd | Extraterritorial | 2022 |
| Blue Sky Financial Group Limited | Financial services | 2018 |
| Blue Sky Internation Trading Limited | Manufacturing | 2023 |
| Blue Sky Visions Limited | Information & communication | 2007 |
| Blue Star Coffee Ltd | Professional & scientific | 2014 |
| Blue Turbo Group Co., Ltd | Extraterritorial | 2018 |
| Blue Whale Holding Co Ltd | Extraterritorial | 2019 |
| Bluebell Wood Estates Ltd. | Real estate | 2020 |
| Bluebird Advertising Co., Limited | Manufacturing | 2023 |
| Blueco Machinery Co., Ltd. | Wholesale & retail | 2018 |
| Bluecoat Engineering Limited | Manufacturing | 2011 |
| Bluecrate Ventures Ltd | Wholesale & retail | 2025 |
| Blueprint and Design Limited | Manufacturing | 2002 |
| Bluesea Winway International Ltd | Extraterritorial | 2013 |
| Bluestone Quinette Ltd | Administrative & support | 2019 |
| Bluocean Industrial Co., Ltd. | Wholesale & retail | 2022 |
| Bluston Composites Material Co., Ltd | Professional & scientific | 2014 |
| Bluwave Ltd | Manufacturing | 2003 |
| Blyth House Management Limited | Households | 1999 |
| Blyton House RTM Company Limited | Households | 2012 |
| BMI Handel Ltd | Manufacturing | 2023 |
| Bmkn Investments Limited | Financial services | 2023 |
| Bmst Limited | Administrative & support | 2017 |
| BN Drainage Ltd | Water & waste | 2020 |
| BNT Piping Engineering and Solution Co., Ltd. | Manufacturing | 2025 |
| BO Entertainment Ltd | Wholesale & retail | 2017 |
| BO Shuo Investments Ltd | Manufacturing | 2024 |
| BOA Therapy Limited | Health & social care | 2019 |
| Boas Investment Limited | Financial services | 2008 |
| Bocatta Limited | Hospitality | 2023 |
| Boda Limited | Mining & quarrying | 2025 |
| Bodarpen Manufacturing Co., Ltd | Manufacturing | 2024 |
| Bogoi Limited | Wholesale & retail | 2021 |
| Bohai Machinery Equipment Ltd. | Extraterritorial | 2019 |
| Bohan Marine Agent Co., Ltd | Manufacturing | 2023 |
| Bohec Energy Group Corporation Ltd | Mining & quarrying | 2022 |
| Bohi Industrial (China) Ltd | Extraterritorial | 2014 |
| Bold House Ltd | Professional & scientific | 2019 |
| Bolland Group Limited | Extraterritorial | 2019 |
| Bolldon International Co., Ltd | Wholesale & retail | 2023 |
| Boluo Trading Co., Ltd | Wholesale & retail | 2021 |
| Bombardier Ltd. | Manufacturing | 2023 |
| BON Vivant Consulting Limited | Professional & scientific | 2025 |
| Bonccino Building Materials Limited | Wholesale & retail | 2020 |
| Bond Aesthetics Clinic Ltd | Health & social care | 2025 |
| Bond Building Services Limited | Construction | 2000 |
| Bond Drainage & Plumbing Ltd | Construction | 2024 |
| Bonda Group Co., Ltd | Extraterritorial | 2017 |
| Bones Meadow Management Company Limited | Households | 2020 |
| Bonny Valve Co., Ltd | Extraterritorial | 2014 |
| Bonus Stage Ltd | Information & communication | 2020 |
| Bonvoyage Maritime Tech Developing (UK) Co., Limited | Manufacturing | 2023 |
| BOO PR + Marketing Limited | Professional & scientific | 2016 |
| Bookabooth Ltd | Professional & scientific | 2017 |
| Bookim Ltd | Manufacturing | 2023 |
| Bookswizard Limited | Professional & scientific | 2023 |
| Booling Industrial Co., Ltd | Extraterritorial | 2014 |
| Boom Boom Events Ltd | Hospitality | 2018 |
| Booze Jewelry Co., Ltd | Extraterritorial | 2024 |
| Boranpee Health Care Limited | Administrative & support | 2023 |
| Borrowme Ltd | Information & communication | 2025 |
| Bosense International Group Limited | Extraterritorial | 2014 |
| Boss Uhealth Bioscience Academy | Professional & scientific | 2024 |
| Boston Meadows Property Company Limited | Construction | 2002 |
| Bothwell Industry Co., Ltd | Extraterritorial | 2015 |
| Botinkit (UK) Limited | Extraterritorial | 2024 |
| Boto Group Ltd | Manufacturing | 2021 |