| Blake Electrical Contractors Ltd | Construction | 2023 |
| Blanchard Engineering Limited | Manufacturing | 2017 |
| Blanchard Fabricators Limited | Manufacturing | 2026 |
| Blaze Fire Doors Ltd | Construction | 2025 |
| Bldc Ltd | Wholesale & retail | 2000 |
| Bleez Inns Limited | Hospitality | 2017 |
| Blenheim Park Developments Limited | Construction | 2003 |
| Blesson Strand and Style Ltd | Wholesale & retail | 2026 |
| Blick Dormants Limited | Extraterritorial | 1963 |
| Blick Engineering Limited | Extraterritorial | 1949 |
| Blick Group Management Services Limited | Extraterritorial | 1977 |
| Blick International Limited | Extraterritorial | 1977 |
| Blick International Systems Limited | Extraterritorial | 1926 |
| Blick Maintenance Limited | Extraterritorial | 1951 |
| Blick National Systems Limited | Extraterritorial | 1964 |
| Blick Properties Limited | Extraterritorial | 1943 |
| Blick Software Systems Limited | Extraterritorial | 1982 |
| Blick Tannoy Limited | Extraterritorial | 1958 |
| Blick Telefusion Communications Limited | Extraterritorial | 1980 |
| Blick Time Recorders Limited | Extraterritorial | 1979 |
| Blick Time Systems Limited | Extraterritorial | 1933 |
| Blindmasters (South Yorkshire) Limited | Manufacturing | 2004 |
| BLM Christopher LEE Financial Services Limited | Financial services | 1999 |
| BLM Insurance Services Limited | Administrative & support | 1999 |
| Block Consulting Ltd | Other services | 2024 |
| Bloom Bar Bloom Ltd | Hospitality | 2024 |
| Bloom by Rose Limited | Wholesale & retail | 2025 |
| Bloor & SON Ltd | Real estate | 2025 |
| Blossom EOT Limited | Financial services | 2025 |
| BLS Waste Solutions Limited | Water & waste | 2020 |
| BLU 27 Ltd | Wholesale & retail | 2020 |
| Blue Boys Cleaning Services Limited | Administrative & support | 2022 |
| Blue Chip Plumbing & Heating Ltd | Construction | 2026 |
| Blue JAM Ltd | Real estate | 2015 |
| Blue Moon Inns Ltd | Hospitality | 2025 |
| Blue OWL Investment Ltd | Real estate | 2023 |
| Blue Star Fleet Services Ltd | Administrative & support | 2010 |
| Bluebell Bridge Ltd | Information & communication | 2018 |
| Bluebolt Site Services Ltd | Construction | 2025 |
| Bluee-Sky Limited | Wholesale & retail | 2024 |
| Blueline Estates Limited | Real estate | 2015 |
| Bluenest Properties Ltd | Administrative & support | 2025 |
| Bluetee Ltd | Information & communication | 2018 |
| Bluetide Properties Ltd | Real estate | 2026 |
| Bluetree Medical Limited | Extraterritorial | 1999 |
| Bluetree Print Limited | Manufacturing | 2021 |
| Blunt Homes LLP | | 2011 |
| Blush Beauty Treatments Ltd | Other services | 2018 |
| BLY Bond Limited | Health & social care | 2014 |
| Blyton Ice Cream Trading Ltd | Manufacturing | 2026 |
| BM Educational Services Ltd | Education | 2020 |
| BM Technocold Ltd | Professional & scientific | 2020 |
| BMC Electrical Ltd | Construction | 2016 |
| BMD Haulage Ltd | Transport & logistics | 2016 |
| BMD Real Estates Ltd | Real estate | 2025 |
| BMD Transforce Limited | Transport & logistics | 2020 |
| BMF Services (UK) Limited | Administrative & support | 2003 |
| BMF Trans Ltd | Transport & logistics | 2026 |
| Bmgc Property Ltd | Real estate | 2012 |
| BMR Drywall Limited | Construction | 2021 |
| BMS Integration Limited | Construction | 2013 |
| BNB Systems Ltd | Information & communication | 2013 |
| Boat Bars Limited | Hospitality | 2013 |
| Boates Planning Ltd | Professional & scientific | 2024 |
| BOB Blackie Communications Limited | Construction | 2018 |
| Bobinsana Ltd | Wholesale & retail | 2025 |
| Bobo Intl Ltd | Administrative & support | 2025 |
| Bodies's Bakes Ltd | Hospitality | 2025 |
| Body Carnegie Ltd | Arts & recreation | 2013 |
| Bole Hill Leisure Ltd | Hospitality | 2025 |
| Bolle Holdings Ltd | Real estate | 2023 |
| Bolo Holdings Ltd | Real estate | 2018 |
| Bolt Property Maintenance Ltd | Construction | 2023 |
| Bolt Scaffold Ltd | Construction | 2013 |
| Bond Chemicals Limited | Wholesale & retail | 2003 |
| Bond Plumbing & Heating Limited | Construction | 2013 |
| Bonobo Services Ltd | Professional & scientific | 2020 |
| Boocat Solutions Ltd | Other services | 2018 |
| Bookings With ST Ltd | Wholesale & retail | 2026 |
| Books & Catalogues Ltd | Manufacturing | 2014 |
| Booms Vintage Ltd | Wholesale & retail | 2024 |
| Boot Camp Sheffield Ltd | Arts & recreation | 2021 |
| Booth Interiors Ltd | Construction | 2025 |
| Booth Lynch & Co Limited | Professional & scientific | 2014 |
| Booth's Real Estate Ltd | Real estate | 2021 |
| Bootroom Limited | Information & communication | 2024 |
| Boraexpedition Ltd | Construction | 2021 |
| Boraid Risk Ltd | Professional & scientific | 2025 |
| Boreflex Limited | Wholesale & retail | 1996 |
| Borral & Co Ltd | Real estate | 2020 |
| Bosco Coffee Limited | Professional & scientific | 2018 |
| Bosco Prime Limited | Other services | 2013 |
| Boss EZ Limited | Hospitality | 2026 |
| Boss TUP Holdings Limited | Manufacturing | 2020 |
| Bossman Transport Ltd | Transport & logistics | 2025 |
| Bostan Boxing Limited | Arts & recreation | 2025 |
| Botonix Derma Clinic Ltd | Other services | 2025 |
| Bouncing Bros Ltd | Arts & recreation | 2025 |
| Bourn Electrical Contracting Ltd | Construction | 2019 |
| Bowdenca Limited | Health & social care | 2009 |