| Bishop Fleming Audit Partners LLP | | 2025 |
| Bishop Fleming Corporate Finance Limited | Extraterritorial | 2000 |
| Bishop Fleming Holding Company Limited | Professional & scientific | 2024 |
| Bishop Fleming LLP | | 2014 |
| Bishop Fleming Management Services Limited | Professional & scientific | 2002 |
| Bishop Fleming Probate Limited | Professional & scientific | 2025 |
| Bishop Fleming Secretarial Limited | Professional & scientific | 2004 |
| Bishop Fleming Trustee Company Limited | Professional & scientific | 2012 |
| Bishops Court Property Ltd | Construction | 2022 |
| Bishops Park Group Ltd | Manufacturing | 2024 |
| Bishops Park Holding Ltd | Hospitality | 2021 |
| Bishopshousercg Ltd | Health & social care | 2019 |
| Bistro EXE Limited | Hospitality | 2022 |
| Bitpod Limited | Information & communication | 2011 |
| Bitsandboards Ltd | Wholesale & retail | 2025 |
| Bitstack Crowd Limited | Financial services | 2026 |
| Bittern Management Company Limited | Extraterritorial | 1989 |
| Bittern Road Management Company Limited | Real estate | 2000 |
| Bizastra Ltd | Professional & scientific | 2025 |
| Bizzie Baking Ltd | Hospitality | 2025 |
| Bjca Limited | Professional & scientific | 2005 |
| Bjca Property Limited | Real estate | 2007 |
| BJH Tree and Grounds Maintenance Ltd | Agriculture & fishing | 2018 |
| BKR Property Innovations Ltd | Construction | 2024 |
| Black and Grey Ltd | Real estate | 2013 |
| Black Country Sales and Lettings Limited | Real estate | 2024 |
| Black HAT Ventures Ltd. | Financial services | 2025 |
| Black Petal Collective Ltd | Other services | 2025 |
| Black Rock Cafe Limited | Hospitality | 2020 |
| Black Tree Gaming Limited | Administrative & support | 2007 |
| Blackberry Gardens Limited | Administrative & support | 2009 |
| Blackberry Holdings Ltd | Real estate | 2021 |
| Blackboy Road Properties Ltd | Real estate | 2026 |
| Blackbrook Investments Ltd | Extraterritorial | 2011 |
| Blackdown Hills Living Limited | Construction | 2021 |
| Blackdown Orthopaedic and Spinal Services LLP | | 2007 |
| Blackheath Court Management Company Limited | Households | 1987 |
| Blackhill 2023 Limited | Energy | 2023 |
| Blackingstone Wildlands Ltd | Agriculture & fishing | 2025 |
| Blackmore (Exeter) Flats Management Co. Limited | Households | 1988 |
| Blackperry Properties Ltd | Real estate | 2021 |
| Blagdon Properties Ltd | Real estate | 2024 |
| Blairs Garage Ltd | Wholesale & retail | 2019 |
| Blakemere Consulting Ltd | Professional & scientific | 2021 |
| Blakeside Holdings Limited | Financial services | 2024 |
| Blamps Scaffolding Ltd | Construction | 2014 |
| Blatchfords International Movements Limited | Extraterritorial | 1992 |
| Blattler Limited | Administrative & support | 2003 |
| Blaythorne Group Limited | Wholesale & retail | 2007 |
| Blaze Concepts Ltd | Information & communication | 2015 |
| Blazeby Maritime Consultants Ltd | Professional & scientific | 2015 |
| Bleu Blanc Red Ltd | Professional & scientific | 2014 |
| BLH (SW) Scaffolding Ltd | Construction | 2019 |
| Blind Ditch Ltd | Arts & recreation | 2008 |
| Blink 24 Distribution (UK) Limited | Wholesale & retail | 2019 |
| Bliss Technologies Ltd. | Professional & scientific | 1996 |
| Blizzard & Finch Holdings Ltd | Financial services | 2020 |
| Bloaters Limited | Wholesale & retail | 2015 |
| Block Birmingham Ltd | Administrative & support | 2026 |
| Block Bristol Ltd | Administrative & support | 2023 |
| Block Group Limited | Financial services | 2026 |
| Block Manchester Ltd | Administrative & support | 2026 |
| Block Workspace Ltd | Administrative & support | 2023 |
| Block Workspace Taunton Limited | Administrative & support | 2022 |
| Blockchain Crowd Limited | Extraterritorial | 2026 |
| Blondin Management Ltd | Real estate | 2023 |
| Bloom Boutique Holdings Ltd | Financial services | 2019 |
| Bloom Boutique Ltd | Wholesale & retail | 2014 |
| Bloomhouse Properties Ltd | Real estate | 2023 |
| Blow a Million Productions (BAM) Limited | Information & communication | 2015 |
| Blowfish Branding Ltd | Professional & scientific | 2016 |
| BLS Wholesale Ltd | Manufacturing | 2022 |
| BLT Southwest Limited | Households | 2006 |
| Blue Castle Estate Limited | Real estate | 2026 |
| Blue Cedar Homes Limited | Construction | 2007 |
| Blue Elephant (Llanelli) Ltd | Hospitality | 2003 |
| Blue Flame Recruitment Limited | Administrative & support | 2007 |
| Blue Harmony Ltd | Wholesale & retail | 2023 |
| Blue Husky Ltd | Other services | 2020 |
| Blue Investments Devon Ltd | Real estate | 2022 |
| Blue Island Media Ltd | Information & communication | 2007 |
| Blue Ocean Creative Limited | Administrative & support | 2005 |
| Blue Ocean Limited | Wholesale & retail | 2006 |
| Blue PEN (SW) Ltd | Arts & recreation | 2025 |
| Blue PIP Productions Limited | Information & communication | 2012 |
| Blue Seas 5D Ltd | Professional & scientific | 2020 |
| Blue Sky Property Rentals Ltd | Real estate | 2022 |
| Blue Sky SW Limited | Wholesale & retail | 2026 |
| Blue Sun Destinations Ltd | Administrative & support | 2010 |
| Bluebell Communications Systems Limited | Manufacturing | 2010 |
| Bluebell Ecology Limited | Professional & scientific | 2007 |
| Bluebell Projects Services Limited | Professional & scientific | 2015 |
| Bluebrook Ltd | Health & social care | 2026 |
| Blueglade Cleaning Services Ltd | Administrative & support | 2025 |
| Bluematch Global Limited | Professional & scientific | 2020 |
| Blueridge Projects Group Ltd | Financial services | 2020 |
| Bluesky Advisory Limited | Information & communication | 2025 |
| Bluesky Copywriting | Administrative & support | 2011 |
| Bluestone Wealth Ltd | Financial services | 2016 |
| Bluetube Limited | Extraterritorial | 2013 |