| Aspen London Ltd | Wholesale & retail | 2011 |
| Asset Logical Ltd | Real estate | 2022 |
| Assiem Limited | Administrative & support | 2009 |
| ATC Southern Limited | Agriculture & fishing | 2003 |
| Atkin Developments Limited | Real estate | 1997 |
| Atrium CSV Limited | Professional & scientific | 1987 |
| Atrium Property Services Limited | Extraterritorial | 2021 |
| Audio Assist Limited | Information & communication | 2011 |
| Audio Vision Integration Ltd | Wholesale & retail | 2013 |
| Avionics Technical Support Ltd | Manufacturing | 2026 |
| Axis Industrial Services Ltd | Manufacturing | 2026 |
| Ayjay Living Ltd | Real estate | 2012 |
| B&R Benton Property Limited | Financial services | 2022 |
| B.L.W. Limited | Real estate | 1987 |
| B3JA Ltd | Real estate | 2019 |
| BAD Wolf Group Ltd | Education | 2025 |
| Balcombe Pest Control Limited | Administrative & support | 2009 |
| Baldwin & Robinson Holdings Ltd | Financial services | 2019 |
| Baldwin & Robinson Limited | Professional & scientific | 2013 |
| Ballantyne Marketing Limited | Professional & scientific | 2025 |
| Barrow & Thompkins Connexions Ltd | Information & communication | 2009 |
| Bartels Rawlings Company Ltd | Wholesale & retail | 2023 |
| Bartels Rawlings International Limited | Wholesale & retail | 2009 |
| Basil the Spaniel Company Limited | Information & communication | 2010 |
| Bateman Associates Ltd | Financial services | 2025 |
| Battle of the Brits Limited | Arts & recreation | 2020 |
| Baynton Estates Limited | Real estate | 1998 |
| BE DO & Have Anything Limited | Education | 2009 |
| BE YOU 101 CIC | Education | 2024 |
| Beach Shaw Heights Management Company Limited | Households | 2019 |
| Beamsley Associates Limited | Professional & scientific | 2014 |
| Beaumont Portnall Associates Limited | Professional & scientific | 2005 |
| BEE Eater Holdings Ltd | Financial services | 2021 |
| Beechwood Place Management Company Limited | Real estate | 2011 |
| BELA11 Ltd | Construction | 2026 |
| Bella Luna Events Ltd | Other services | 2024 |
| Bellenham Limited | Professional & scientific | 2013 |
| Belvedere Court RTM Company Limited | Households | 2023 |
| Ber-Gur Ltd | Hospitality | 2015 |
| Beresfords Limited | Administrative & support | 1988 |
| Betterpad Ltd | Professional & scientific | 2017 |
| BGK House Ltd | Hospitality | 2015 |
| Bicknell Associates Ltd | Professional & scientific | 2021 |
| Birchtree Properties Limited | Construction | 1960 |
| Bircotes Land Limited | Real estate | 2022 |
| BIZ Empire Group Ltd | Administrative & support | 2023 |
| Blank Slate Group Limited | Administrative & support | 2026 |
| BLC Promotions Ltd | Professional & scientific | 2023 |
| Bliss Architecture Limited | Professional & scientific | 2018 |
| Bliss Interiors Limited | Professional & scientific | 2015 |
| Blue Analytics Ltd | Information & communication | 2012 |
| Blue Atlas Cedar Ltd | Information & communication | 2022 |
| Blue Interiors London Ltd | Professional & scientific | 2023 |
| Blue Rose Relations Limited | Information & communication | 2015 |
| Blue Sky Meats (UK) Limited | Wholesale & retail | 2000 |
| Blue Sky Properties Limited | Construction | 1962 |
| Blueoceansky Limited | Professional & scientific | 2018 |
| Blueprints Surveying Ltd | Professional & scientific | 2024 |
| Bluesky Investment Properties Limited | Real estate | 2025 |
| Blush Cocktails Limited | Hospitality | 2024 |
| BN European Tours Limited | Administrative & support | 2014 |
| BNB Audio Services Limited | Information & communication | 2006 |
| BO Training Ltd | Education | 2015 |
| Bobbio Ltd | Other services | 2008 |
| Body Control Pilates Academy Limited | Education | 2019 |
| Body Control Pilates Central Limited | Education | 2023 |
| Body Control Pilates Education Limited | Education | 2001 |
| Boldly-Go Leadership Limited | Professional & scientific | 2015 |
| Bonaly House (Freehold) Company Limited | Other services | 2005 |
| Boost Fit Limited | Arts & recreation | 2016 |
| Bootcamp Limited | Arts & recreation | 2020 |
| Boswell Medical Writing Ltd | Professional & scientific | 2019 |
| Boxbuild Holdings Limited | Financial services | 2017 |
| Boxbuild Limited | Construction | 2008 |
| Boxtsolutions Limited | Information & communication | 2007 |
| Braai Time Ltd | Wholesale & retail | 2022 |
| Brake Works Ltd | Wholesale & retail | 2023 |
| Bralim Limited | Households | 1995 |
| Brambles of Oxted Limited | Health & social care | 2020 |
| Breathe Inner Peace Ltd | Other services | 2022 |
| Brendon Hancocks Ltd | Professional & scientific | 2025 |
| Brian T Gordon & Partners Limited | Wholesale & retail | 2007 |
| Brick and Stone Properties Limited | Construction | 2016 |
| Briggs Energy Consulting Ltd | Other services | 2010 |
| Brightstone Build Limited | Real estate | 2025 |
| Broadcorp Limited | Information & communication | 1998 |
| Broadham Farm Ltd | Financial services | 2024 |
| Broadham Place Management Company Limited | Administrative & support | 1996 |
| Brooklyn Associates Ltd | Administrative & support | 2015 |
| Broseley London Construction Limited | Construction | 2012 |
| Broseley London Contractors Limited | Construction | 2012 |
| Broseley London Group Limited | Construction | 2012 |
| Broseley London Limited | Construction | 2010 |
| Browning Treasury Limited | Professional & scientific | 1998 |
| Brownstone Gate Limited | Professional & scientific | 2006 |
| Brymore Care Homes Limited | Health & social care | 2010 |
| BSM Innovations Ltd | Administrative & support | 2026 |
| BUBBL3 Limited | Professional & scientific | 2021 |
| Buck and Ryan Limited | Professional & scientific | 1938 |
| Buildhour Limited | Construction | 1991 |