| B & E Property Ltd | Administrative & support | 2009 |
| B & L Clark Holdings Limited | Administrative & support | 2023 |
| B C Hughes Plumbing & Heating Limited | Administrative & support | 2016 |
| B C Property Development Limited | Real estate | 2022 |
| B C S Parker Limited | Transport & logistics | 2001 |
| B Electrical Contractors Ltd | Administrative & support | 2024 |
| B M Installations Limited | Construction | 2008 |
| B R S M Brickwork Ltd | Construction | 2025 |
| B White Electrical Limited | Construction | 2018 |
| B&I Construction Ltd | Construction | 2022 |
| B.A. Mcleish Ltd | Wholesale & retail | 2009 |
| B.D.I. Productions Ltd | Information & communication | 2006 |
| B2 Wellness and Fitness Limited | Arts & recreation | 2024 |
| B2BLOUNG Ltd | Hospitality | 2026 |
| Baby Bohemia Limited | Wholesale & retail | 2023 |
| Back ROW Trading Limited | Wholesale & retail | 2025 |
| Backed by Humans Ltd | Information & communication | 2026 |
| Bagzies Limited | Hospitality | 2024 |
| Baig&Co Ltd | Other services | 2011 |
| Bailey & FOX Ltd. | Real estate | 2018 |
| Bailey Inc Ltd | Construction | 2023 |
| Bailiwick Ltd | Information & communication | 2020 |
| Baker Micropubs Limited | Hospitality | 2019 |
| Baker Rend Ltd | Construction | 2018 |
| BAL Krishna Education Trust | Education | 2018 |
| Balaji Pharmaceutical Ltd | Wholesale & retail | 2009 |
| Ball-Craft Academy Limited | Arts & recreation | 2026 |
| Balmoral Gardens (Bexley) Freehold Limited | Households | 2004 |
| Balneo Build Ltd | Construction | 2024 |
| Balneo Design Ltd | Professional & scientific | 2021 |
| Baltfix Ltd | Construction | 2009 |
| Bampton Roofing Limited | Construction | 2022 |
| Banagard Limited | Hospitality | 2025 |
| Banks Management Limited | Real estate | 2022 |
| Bappoo Ltd | Real estate | 2019 |
| Bar & Catering Services (London) Limited | Administrative & support | 2003 |
| Bararnott Limited | Hospitality | 2023 |
| Barber Pipeline Engineering Ltd | Construction | 2014 |
| Bardhi Consulting Ltd | Professional & scientific | 2026 |
| Bare LA Terre Limited | Wholesale & retail | 2025 |
| Barfield Ltd | Construction | 2024 |
| Barham Planners Limited | Professional & scientific | 2018 |
| Barker Properties Ltd | Real estate | 2018 |
| Barneabbey Limited | Professional & scientific | 2024 |
| Barnes Gold Limited | Real estate | 2012 |
| Barnfield Developments Kent Limited | Administrative & support | 2017 |
| Barnhouse Limited | Financial services | 2023 |
| Barnhouse Properties Limited | Real estate | 2018 |
| Baron Homes Brandram Limited | Real estate | 2017 |
| Baron Homes Bromley Limited | Administrative & support | 2016 |
| Baron Homes Ltd | Administrative & support | 2012 |
| Barot Retail Management Ltd | Wholesale & retail | 2016 |
| Barramanda Limited | Real estate | 2021 |
| Barron of London Limited | Extraterritorial | 2012 |
| Barry and Driscoll Holdings Ltd | Real estate | 2023 |
| Barter Inns Limited | Professional & scientific | 2011 |
| Base Solutions Limited | Professional & scientific | 2012 |
| Bastille Cycles UK Ltd | Wholesale & retail | 2025 |
| Batsalo Limited | Hospitality | 2022 |
| Batsons Foods Limited | Professional & scientific | 1988 |
| Battersea BIM Solutions Ltd | Construction | 2017 |
| Baxter Overseas Properties Ltd | Administrative & support | 2005 |
| BBL Property Developments Limited | Construction | 2013 |
| BC Magpie Limited | Real estate | 2025 |
| BC Properties Investment Limited | Real estate | 2024 |
| BCE Property Services Limited | Real estate | 2025 |
| BCK Interior Ltd | Manufacturing | 2018 |
| BD (Bradbourne) Limited | Administrative & support | 2015 |
| BD (Dartford) Limited | Administrative & support | 2016 |
| BD (Edenbridge) Limited | Administrative & support | 2014 |
| BD (Lamberhurst) Limited | Administrative & support | 2014 |
| BD Food and Wine Limited | Wholesale & retail | 2025 |
| Bdgi Ltd | Water & waste | 2019 |
| Bdgip Ltd | Real estate | 2021 |
| BDM Consulting Ltd | Professional & scientific | 2025 |
| BDT Electrical/Environmental Limited | Construction | 2018 |
| BDT Secretarial Services Ltd | Extraterritorial | 2007 |
| BEA Consultancy Ltd | Administrative & support | 2021 |
| Beagle Properties Limited | Real estate | 2018 |
| Bear Piano Tuition Limited | Education | 2023 |
| Beaupro Developments Ltd | Construction | 2024 |
| Beautiful Electrical Ltd | Construction | 2019 |
| Beautiful Nails (Main Road) Limited | Other services | 2023 |
| Beauty Aesthetics Academy UK Limited | Education | 2021 |
| Beauty Bars London Limited | Other services | 2018 |
| Beck Property Finance Limited | Financial services | 2020 |
| Beckford Contractors Limited | Construction | 2001 |
| Beckingham Decorators Limited | Administrative & support | 2014 |
| Beddow Interiors Limited | Administrative & support | 2012 |
| BEE Property Holdings Ltd | Real estate | 2018 |
| Bekky Email Konsultancy Ltd | Professional & scientific | 2026 |
| Belaccino Limited | Hospitality | 2025 |
| Bella &Co Limited | Health & social care | 2019 |
| Bella Barber Limited | Other services | 2022 |
| Bella Nailuxury Limited | Other services | 2026 |
| Belle Construction Ltd | Construction | 2025 |
| Belle VUE Developments (Kent) Limited | Construction | 2025 |
| Belle VUE Developments (SE) Limited | Construction | 2021 |
| Bellevue Dogs Ltd | Administrative & support | 2020 |
| Bellingers Limited | Administrative & support | 2014 |