| Barossa Residents Company Limited | Households | 2001 |
| Barrec Ltd | Administrative & support | 2022 |
| Bartlett Place Limited | Households | 2002 |
| Barton Allen Limited | Real estate | 2020 |
| Bass & Treble Ltd | Arts & recreation | 2025 |
| Batchworth Park Property Limited | Arts & recreation | 1995 |
| Bath Property Letting Ltd | Extraterritorial | 1988 |
| Bathroom Style UK Ltd | Construction | 2005 |
| Bay Tree Lodge Limited | Households | 1962 |
| Bayland Windows Limited | Construction | 2023 |
| Bayliss Court Management Company Limited | Households | 1996 |
| Bayphase Limited | Professional & scientific | 1986 |
| Bayside Horizon Ltd | Wholesale & retail | 2026 |
| Bayt Ventures Limited | Real estate | 2024 |
| Baywood Computing Services Limited | Information & communication | 2006 |
| Bazarx Limited | Wholesale & retail | 2026 |
| BB Halal Foods Ltd | Wholesale & retail | 2023 |
| BBL Trading Limited | Manufacturing | 2021 |
| BBQ 75 Ltd | Hospitality | 2026 |
| BBQ Time Ltd | Hospitality | 2024 |
| Bbsb Services Ltd | Financial services | 2019 |
| Bccw Estate Limited | Extraterritorial | 2021 |
| Bcomp 497 Limited | Other services | 2015 |
| Bctek Ltd | Professional & scientific | 2023 |
| BD Consulting International Ltd | Administrative & support | 2022 |
| BD Indian Takeaway Limited | Hospitality | 2018 |
| Beam Accountancy Ltd | Professional & scientific | 2011 |
| Bear & Associates Ltd | Professional & scientific | 2021 |
| Beat Media Group Limited | Information & communication | 2002 |
| Beat Media Limited | Extraterritorial | 2023 |
| Beaufort Mews Holdings Limited | Real estate | 2022 |
| Beaufort Mews Management Company Limited | Real estate | 2006 |
| Beaumont Lodge Holdings Limited | Financial services | 2019 |
| Beauty by Fabi Ltd | Other services | 2020 |
| Beauty by Sian Ltd | Other services | 2020 |
| Becker Projects Ltd | Other services | 2025 |
| Beckingham Homes (Alpha) Limited | Real estate | 2014 |
| Beckingham Homes (Alton) Limited | Real estate | 2018 |
| Beckingham Homes (Bagshot) Limited | Real estate | 2015 |
| Beckingham Homes (Frimley) Limited | Construction | 2012 |
| Beckingham Homes (Omega) Limited | Real estate | 2011 |
| Beckingham Homes (Surrey) Limited | Real estate | 2017 |
| Beckingham Homes Limited | Real estate | 2002 |
| BEE MAY E D S Limited | Professional & scientific | 2018 |
| BEE Property Group Limited | Real estate | 2021 |
| BEE Thai Global Food Store Ltd | Wholesale & retail | 2024 |
| BEE Thai Limited | Hospitality | 2026 |
| BEE the Designer Ltd | Professional & scientific | 2026 |
| Beech Building and Development Limited | Construction | 2020 |
| Beechleigh Management Company Limited | Households | 1986 |
| Beezumph Limited | Administrative & support | 2005 |
| Behabitus Ltd | Construction | 2021 |
| BEK Autos Ltd | Wholesale & retail | 2024 |
| Belcher Properties Limited | Real estate | 1965 |
| Belgrave and Belgrave Limited | Real estate | 2020 |
| Belgrave Garden Services Ltd | Administrative & support | 2023 |
| Bell House Management Limited | Households | 1996 |
| Belparga Management Limited | Households | 1989 |
| Belton Woods Lodges Title Limited | Professional & scientific | 2019 |
| Belwood Limited | Households | 1995 |
| BEN Cornfield Limited | Professional & scientific | 2018 |
| Benbenet Ltd | Real estate | 2026 |
| Benevento Ristorante Ltd | Hospitality | 2022 |
| Bennbridge Hold Co Ltd | Financial services | 2016 |
| Bennbridge Services LLP | | 2016 |
| Bennett Residential Limited | Extraterritorial | 2006 |
| Bensha Limited | Health & social care | 2013 |
| Bentleys Plumbing & Heating Ltd | Construction | 2024 |
| Beresford Residential Limited | Real estate | 2009 |
| Berkeley House Residents Company Limited | Households | 2000 |
| Berkshire & Surrey Property Maintenance Limited | Construction | 1988 |
| Berkshire Contractors Ltd | Administrative & support | 2015 |
| Berkshire Engineering and Manufacturing Limited | Manufacturing | 2006 |
| Berkshire Financial Planning Ltd | Financial services | 2020 |
| Berkshire Heathrow Ltd | Professional & scientific | 2020 |
| Berkshire Software Solutions Limited | Information & communication | 2005 |
| Berkshire Turbo Limited | Wholesale & retail | 2020 |
| Bespoke Pilates Limited | Arts & recreation | 2016 |
| Bespoke Silk Limited | Other services | 2016 |
| Besquared Investments Limited | Real estate | 2020 |
| Besquared Limited | Wholesale & retail | 2018 |
| Besson Line Limited | Administrative & support | 1998 |
| Best Chance Properties Limited | Other services | 2020 |
| Best Dressed Events Ltd | Administrative & support | 2022 |
| Bestyear Limited | Real estate | 1996 |
| Better Facilities Maintenance Ltd | Information & communication | 2026 |
| Better Lives (UK) Ltd | Health & social care | 2010 |
| Better World Creative Limited | Extraterritorial | 2014 |
| Bewsey Consulting Limited | Professional & scientific | 2022 |
| Beyond Silos Limited | Professional & scientific | 2025 |
| BH Auto Ltd | Wholesale & retail | 2024 |
| BHC Technology Innovation Co. Ltd | Information & communication | 2026 |
| Bhmr Group Limited | Financial services | 2026 |
| Bholy Limited | Health & social care | 2021 |
| Bhrigenaka Limited | Information & communication | 2025 |
| Bien Travel Limited | Administrative & support | 2024 |
| Big & Small Removals Ltd | Transport & logistics | 2025 |
| Big Merch Ltd | Administrative & support | 2026 |
| Bigbang Creative Guildford Ltd | Professional & scientific | 2010 |
| Bilaller Property Management Limited | Real estate | 2026 |