| Balance PB Limited | Wholesale & retail | 2022 |
| Baldwin Builders (North London) Limited | Construction | 1984 |
| Balermo Consulting Limited | Professional & scientific | 2016 |
| Ball Packaging Ltd | Manufacturing | 2021 |
| Banbu Ltd | Professional & scientific | 2016 |
| Banjo Bear Limited | Real estate | 2019 |
| Bankhall (Bakers Farm) Limited | Real estate | 2012 |
| Bankhall (Carisbrook Grange) Ltd | Real estate | 2008 |
| Bankhall (Eton Place) Limited | Real estate | 2008 |
| Bankhall (Hawthorn Meadows) Limited | Real estate | 2012 |
| Bankhall (Kings Wood Place) Ltd | Real estate | 2008 |
| Bankhall (Marlborough Gardens) Ltd | Real estate | 2008 |
| Bankhall (Marlborough) Limited | Real estate | 2006 |
| Bankhall (Park Gate) Limited | Real estate | 2006 |
| Bankhall (Squirewalk) Limited | Real estate | 2008 |
| Bankhall Limited | Real estate | 2005 |
| Bankland (Artillery Arms) Limited | Real estate | 2006 |
| Bankland (Artillery ROW) Limited | Professional & scientific | 2006 |
| Bankland (Chapel Annexe) Limited | Real estate | 2007 |
| Bankland (Kings Acre) Limited | Real estate | 2012 |
| Bankland (Lakeside) Limited | Real estate | 2007 |
| Bankland (Park 21) Limited | Real estate | 2006 |
| Bankland (Perham) Limited | Real estate | 2007 |
| Bankland (Portswood) Limited | Real estate | 2007 |
| Bankland (Roman Quarter) Limited | Real estate | 2009 |
| Bankland (Staunton) Limited | Real estate | 2007 |
| Bankland (Tangmere) Limited | Real estate | 2009 |
| Bankland (the Orchard) Limited | Real estate | 2007 |
| Bankland Ltd | Real estate | 2005 |
| Baobab Biotechnology UK Ltd | Manufacturing | 2025 |
| Baracuda Catering (Park Mews) Limited | Hospitality | 1968 |
| Barbers Sollaku Ltd | Other services | 2023 |
| Barbertimepb Ltd | Other services | 2025 |
| Barcode Connexions Limited | Professional & scientific | 2004 |
| Bark Soho Limited | Information & communication | 2012 |
| Barnard's Jewellers Limited | Wholesale & retail | 2013 |
| Barnett Ross Insurance Services Limited | Administrative & support | 2005 |
| Barnett Ross Limited | Real estate | 2002 |
| Baseland Limited | Administrative & support | 2012 |
| Batala London Ltd | Arts & recreation | 2010 |
| Batala Mundo Ltd | Arts & recreation | 2023 |
| Batchwood Hall Ltd | Real estate | 2026 |
| Batemans Film & Fabrication Ltd | Manufacturing | 2026 |
| Bayliss Trading Limited | Wholesale & retail | 2005 |
| Bazballers Consulting Limited | Professional & scientific | 2024 |
| BBA Accountancy Ltd | Professional & scientific | 2017 |
| BBA Cafe Ltd | Hospitality | 2020 |
| Bbis Commercial Heating Limited | Administrative & support | 2015 |
| BBS Recruitment Ltd | Administrative & support | 2016 |
| BBW Investments LLP | | 2021 |
| BBX Herts Limited | Other services | 2025 |
| BCP Energy Limited | Construction | 2014 |
| BDA Solutions Ltd | Construction | 2022 |
| Beaconview Services Limited | Real estate | 1999 |
| Bealabs Ltd | Administrative & support | 2016 |
| Beatrix Music Ltd. | Administrative & support | 2012 |
| Beau Sejour Holdings Limited | Financial services | 2018 |
| Beauties of London Limited | Wholesale & retail | 2015 |
| Beautiful Bees Ltd | Transport & logistics | 2025 |
| Beautiful Vision Limited | Health & social care | 2011 |
| Beauty Marketing Solutions Ltd | Wholesale & retail | 2010 |
| Beauty-Direct Ltd. | Other services | 1995 |
| Beaver Catering Ltd | Hospitality | 2025 |
| Bechris Ltd | Administrative & support | 2013 |
| Bedfares Ltd | Information & communication | 2025 |
| Bee's Services Limited | Hospitality | 2023 |
| Beema Properties Limited | Real estate | 2000 |
| Beeot Ltd | Health & social care | 2017 |
| Beevale Properties Limited | Real estate | 2004 |
| Befree Energy Ltd | Construction | 2016 |
| Belectrix Limited | Construction | 2016 |
| Belgrave Vincent Management Company Limited | Households | 2018 |
| Bella Jones Ceramics Ltd | Arts & recreation | 2020 |
| Bellamoo Limited | Professional & scientific | 2022 |
| Bellaview Point Ltd | Real estate | 2023 |
| Bellexio Limited | Health & social care | 2012 |
| Beltons Bars Limited | Arts & recreation | 2024 |
| BEN Krieger Limited | Extraterritorial | 2013 |
| BEN Lottery Ltd | Administrative & support | 2025 |
| Bendron Limited | Professional & scientific | 2003 |
| Benskin Mews Management Company Limited | Real estate | 2004 |
| Benton & Partners Ltd | Administrative & support | 2026 |
| BEP Create Limited | Manufacturing | 2018 |
| Bernachris Healthcare Limited | Administrative & support | 2022 |
| Berric Building Services Ltd | Construction | 2014 |
| Bespoke Blinds London Ltd | Other services | 2019 |
| Bespoke Home Developments Limited | Construction | 2019 |
| Best Friends Childcare Ltd | Education | 2009 |
| Best Test London Ltd | Hospitality | 2026 |
| Best Two Ltd | Wholesale & retail | 2018 |
| Bethany Rich Limited | Other services | 2005 |
| Better by Design Consultancy Ltd | Professional & scientific | 2011 |
| Better Enterprises Limited | Information & communication | 2016 |
| Better Planet (UK) Limited | Construction | 2012 |
| Better Planet Holding Limited | Financial services | 2024 |
| Beulah Prestige Ltd | Wholesale & retail | 2025 |
| Beyond Reach Cleaning Co. Limited | Administrative & support | 2019 |
| BGF Real Estate Limited | Real estate | 2022 |
| BGF Tradings Hub Limited | Wholesale & retail | 2023 |
| Bgpp Ltd | Real estate | 2021 |