| Biddulph Sands Limited | Administrative & support | 1997 |
| Bientransport Ltd | Transport & logistics | 2019 |
| Big Discount Store Crewe Ltd | Wholesale & retail | 2021 |
| Big Eyes MT Ltd | Transport & logistics | 2019 |
| Big KID Entertainment Limited | Arts & recreation | 2005 |
| Big Mugs Ltd | Hospitality | 2024 |
| Big Red Gorilla UK Ltd | Wholesale & retail | 2025 |
| Biju M Thomas Ltd | Wholesale & retail | 2024 |
| BIK 83 Limited | Transport & logistics | 2017 |
| Bikbox Events Limited | Hospitality | 2018 |
| Bikezone Motorcycle Training Limited | Arts & recreation | 2010 |
| Billi Smiles Entertainment Limited | Arts & recreation | 2013 |
| Billington Rail Services Ltd | Manufacturing | 2019 |
| Bingham Conveyancing Consultants Ltd | Professional & scientific | 2023 |
| Bio-Busters Ltd | Administrative & support | 2025 |
| Bio-Raze Limited | Manufacturing | 2022 |
| Biocamat Consults Limited | Professional & scientific | 2024 |
| Biometric Chain Security Ltd | Information & communication | 2024 |
| Birizan Construct Ltd | Construction | 2026 |
| Bispara Ltd | Wholesale & retail | 2025 |
| Bitezz Limited | Manufacturing | 2026 |
| Bitronic Systems Ltd | Manufacturing | 2014 |
| Biurokrat CRW Ltd | Professional & scientific | 2024 |
| Biurokrat Ltd | Extraterritorial | 2018 |
| Bjjko Ju-Jitsu and Kobudo Organisation Ltd | Education | 2019 |
| BKH Holdings Limited | Administrative & support | 2006 |
| Black Cat Recruitment Ltd | Administrative & support | 2016 |
| Black Cat Talent Ltd | Professional & scientific | 2020 |
| Black Dog Gardens Ltd | Administrative & support | 2021 |
| Black Feather Taverns Ltd | Hospitality | 2026 |
| Black Medlar Ltd | Construction | 2021 |
| Black Rock Road Repairs Ltd | Administrative & support | 2023 |
| Black Tower Property Management Ltd | Real estate | 2019 |
| Blackintrusive Limited | Information & communication | 2020 |
| Blackmill Enterprises Limited | Information & communication | 2014 |
| Blackrose Sonu Ltd | Health & social care | 2026 |
| Blackstone & Keys Ltd | Real estate | 2025 |
| Blgm Consulting Limited | Professional & scientific | 2024 |
| Bloc+Blur Creative Studio Limited | Information & communication | 2013 |
| Blonde Hair Salon Ltd | Other services | 2018 |
| Blondette Properties Limited | Extraterritorial | 2022 |
| Bloom Careers Ltd | Administrative & support | 2021 |
| Bloor & Finlayson Construction Ltd | Construction | 2019 |
| BLU Bryn Ltd | Financial services | 2025 |
| BLU Tulip Limited | Wholesale & retail | 2011 |
| Blue Beetle Media Ltd | Information & communication | 2019 |
| Blue Bell Close (Wrinehill) Management Company Limited | Households | 2017 |
| Blue Collar Competitions Ltd | Wholesale & retail | 2026 |
| Blue NSW Ltd | Construction | 2024 |
| Blue Sky Nine Limited | Financial services | 2024 |
| Blue Skye Investments Ltd | Extraterritorial | 2022 |
| Blue Sorcerer Consulting Ltd | Information & communication | 2009 |
| Blue Tractor Projects Ltd | Administrative & support | 2022 |
| Bluebloomsco Ltd | Wholesale & retail | 2026 |
| Bluefield PIC Limited | Real estate | 2023 |
| Bluepeak Technologies Ltd | Information & communication | 2025 |
| Blueprint Outreach Ltd | Professional & scientific | 2026 |
| Blueshoes Limited | Information & communication | 2013 |
| Bluey Healthcare Ltd | Administrative & support | 2023 |
| Blundell Property & Lettings Management Limited | Real estate | 2022 |
| Bmmdesigns Ltd | Construction | 2016 |
| BMP Logistics Ltd | Transport & logistics | 2019 |
| BNF Trading Ltd | Professional & scientific | 2022 |
| BOB Shop 33 Ltd | Wholesale & retail | 2026 |
| Boca UK Propertis Ltd | Real estate | 2024 |
| Body Strong Ltd | Arts & recreation | 2016 |
| Bold in Your Grace Limited | Wholesale & retail | 2023 |
| Boll Transport Ltd | Transport & logistics | 2025 |
| Bombay 1959 Limited | Hospitality | 2022 |
| Bombay Crewe Ltd | Hospitality | 2015 |
| Bombay Fine Indian Cuisine Limited | Hospitality | 2025 |
| Bombaye Junction Limited | Hospitality | 2022 |
| Bonaparte Farm Limited | Agriculture & fishing | 2017 |
| Boom Energy Limited | Professional & scientific | 2016 |
| Boom Telecom Networks Ltd | Information & communication | 2025 |
| Boost Group Limited | Administrative & support | 2007 |
| Bootcamp Retreats Limited | Arts & recreation | 2018 |
| Boothtube Limited | Arts & recreation | 2016 |
| Border Counties Trading Limited | Hospitality | 2024 |
| Borders Livestock Services Ltd | Agriculture & fishing | 2003 |
| Boss Babes Limited | Other services | 2015 |
| Botaku Logistics Ltd | Transport & logistics | 2026 |
| Botany and Naturals Limited | Wholesale & retail | 2025 |
| Bottoms Farm Management Company Limited | Real estate | 2005 |
| Botty LLP | | 2011 |
| Bouncing Buddies Limited | Administrative & support | 2026 |
| Boundary Layers Integrators & Securitisation Specialists LLP | | 2009 |
| Bouqueron Limited | Real estate | 2023 |
| Bowers Engineering Ltd | Professional & scientific | 2025 |
| Bowers Opticians Limited | Health & social care | 2002 |
| Bowler Contractors Limited | Extraterritorial | 2011 |
| Box CPR Ltd | Education | 2026 |
| Boxcross Limited | Arts & recreation | 2013 |
| Boxsmith Steel Ltd | Manufacturing | 2024 |
| Boyds International Life Sciences Group Limited | Health & social care | 2021 |
| Bppro Automotive Ltd | Wholesale & retail | 2018 |
| BPS Building Solutions Ltd | Financial services | 2024 |
| Bpsn Group Limited | Wholesale & retail | 2023 |
| Bradbury Procurement Limited | Administrative & support | 2016 |
| Bradleys Heating and Plumbing Limited | Construction | 2022 |