| Baruch Holdings Limited | Real estate | 1993 |
| Baruch Investments Limited | Professional & scientific | 2001 |
| Base Empire Ltd | Arts & recreation | 2018 |
| Base Furnishings Limited | Wholesale & retail | 2010 |
| Basic Sense Limited | Wholesale & retail | 2018 |
| Basra OIL Company Suppliers Limited | Wholesale & retail | 2025 |
| Basri Transport Ltd | Transport & logistics | 2017 |
| Bateekha Ltd | Administrative & support | 2025 |
| Bathland (UK) Limited | Construction | 2002 |
| Bathouse Limited | Households | 2021 |
| Batterymasters Limited | Extraterritorial | 2012 |
| Bavrock Ltd | Extraterritorial | 2023 |
| Baykul Limited | Wholesale & retail | 2021 |
| Baykus Foods Ltd | Hospitality | 2013 |
| BC Cafe Ltd | Hospitality | 2024 |
| Bdmd Contracts Limited | Construction | 2009 |
| BDS Residentials Limited | Real estate | 2026 |
| BE Services Ltd | Construction | 2023 |
| Bea's Edits Ltd | Wholesale & retail | 2025 |
| Beacon Bridge Limited | Information & communication | 2015 |
| Beams 4 U Ltd | Construction | 2013 |
| Beams Production Limited | Arts & recreation | 2021 |
| Beardstreak Ltd | Wholesale & retail | 2025 |
| Beatdown Entertainment Ltd | Arts & recreation | 2024 |
| Beats N Brotherhood Limited | Information & communication | 2004 |
| Beauty by Hina Ltd | Other services | 2018 |
| Beauty by Neeta Ltd | Other services | 2025 |
| Beauty by Nilam Ltd | Other services | 2022 |
| Beauty Perfume London Limited | Wholesale & retail | 2023 |
| Bedayet Al-Tareeq Limited | Wholesale & retail | 2024 |
| Bedford Legends Limited | Hospitality | 2023 |
| Beech Cottage Electrical Ltd | Administrative & support | 2019 |
| Beech House Residential Care Home Ltd | Health & social care | 2007 |
| Beegutsy Ltd | Other services | 2024 |
| Beguile Corp Ltd | Wholesale & retail | 2023 |
| Beirut Plaza Limited | Hospitality | 2025 |
| Beis Brucha Limited | Health & social care | 2009 |
| Beit Shvidler Primary School Charitable Trust | Education | 2006 |
| Bel-Mar Trade Ltd | Construction | 2022 |
| Belfast Service for YOU Limited | Professional & scientific | 2023 |
| Belgravia Holding Group Ltd | Real estate | 2026 |
| Bellhall Limited | Administrative & support | 2006 |
| Bello Jonga Accountancy Services Limited | Professional & scientific | 2017 |
| BEN Banayo Ltd | Information & communication | 2011 |
| BEN Vale Asset Management Ltd | Real estate | 2022 |
| Benian Transport Limited | Transport & logistics | 2017 |
| Benitoite Investments Limited | Extraterritorial | 2017 |
| Benpol Limited | Manufacturing | 2018 |
| Benvale Property Ltd | Construction | 2024 |
| Berkat Investments Ltd | Real estate | 2024 |
| Bernadette Mary Felix Limited | Extraterritorial | 2025 |
| Bernstein & Banleys Limited | Wholesale & retail | 1953 |
| Besha Zangana Ltd | Health & social care | 2023 |
| Bespoke Kids Clothing Ltd | Wholesale & retail | 2022 |
| Best & Less Construction Ltd | Construction | 2025 |
| Best Bodywork Solutions Ltd | Wholesale & retail | 2020 |
| Best Choice Build Ltd | Other services | 2018 |
| Best Distribution UK Limited | Wholesale & retail | 2018 |
| Best Rate Cleaning Ltd | Administrative & support | 2018 |
| Best Rates Removals Ltd | Other services | 2011 |
| Bestmartin Limited | Real estate | 1972 |
| Bethesda Property Management Ltd | Real estate | 2017 |
| Better Choice Limited | Wholesale & retail | 2004 |
| Betterspecs Greenford Limited | Wholesale & retail | 2008 |
| Betterworking Limited | Professional & scientific | 2013 |
| Betterworks CIC | Education | 2025 |
| Beyond Building Design Ltd | Professional & scientific | 2022 |
| BFC Logistics Ltd | Transport & logistics | 2016 |
| Bfoods Ltd | Hospitality | 2019 |
| BGM Property Holdings Ltd. | Real estate | 2022 |
| BGN Contracting Ltd | Construction | 2019 |
| Bgzi Limited | Construction | 2010 |
| Bharat OIL Limited | Manufacturing | 2026 |
| Bhdn Holding Limited | Financial services | 2023 |
| Bhdn Properties Ltd | Construction | 2024 |
| BHF Bakes Ltd | Agriculture & fishing | 2025 |
| Bhullar Render Ltd | Construction | 2025 |
| BHW Limited | Other services | 2009 |
| Bicom Systems Limited | Wholesale & retail | 2005 |
| Biddy Arnott Limited | Health & social care | 2010 |
| Big BEN Coaches Limited | Transport & logistics | 2016 |
| Big Boys Cafe Ltd | Hospitality | 2019 |
| Big John Grab Service Ltd | Water & waste | 2018 |
| Big Portion International Location Caterers Limited | Hospitality | 2012 |
| Bigbest Construction Ltd | Construction | 2025 |
| Bigbro International Ltd | Manufacturing | 2024 |
| Bigquests Limited | Information & communication | 2014 |
| Bijli Consulting Limited | Administrative & support | 2025 |
| Binkul Transport Ltd | Transport & logistics | 2026 |
| Biolife Longevix Ltd | Wholesale & retail | 2025 |
| Birchen Building and Maintenance Limited | Construction | 2015 |
| Birdys Transport Limited | Transport & logistics | 2025 |
| Birkbeck Consultancy Ltd | Information & communication | 2024 |
| Bishopston Limited | Real estate | 2002 |
| Bits PS Ltd | Professional & scientific | 2010 |
| BIV Transport Ltd | Transport & logistics | 2019 |
| BIZ Bize UK Ltd | Wholesale & retail | 2025 |
| BIZ Connections Limited | Information & communication | 2013 |
| BJR SAL Synergy Limited | Financial services | 2024 |
| BK Team Ltd | Construction | 2025 |