| Berkan Ozgur Ltd | Wholesale & retail | 2026 |
| Berkil & Co Ltd | Wholesale & retail | 2026 |
| Berkley Roofing and Building Ltd | Construction | 2026 |
| Berkshire SL5 Ltd | Real estate | 2024 |
| Bernadette Properties Ltd | Real estate | 2025 |
| Berra Ltd | Construction | 2013 |
| Berry Farm (Wycombe) Limited | Real estate | 2015 |
| Berry Farm Land Limited | Households | 2016 |
| Bertyt Ltd | Wholesale & retail | 2023 |
| Beryl Global Limited | Real estate | 2016 |
| Beryozlondon Limited | Wholesale & retail | 2019 |
| Berzan Ltd | Real estate | 2025 |
| Besa Developments Group Ltd | Construction | 2026 |
| Beseka Ltd | Wholesale & retail | 2025 |
| Besey Ltd | Hospitality | 2016 |
| Beside the Seaside Limited | Hospitality | 2009 |
| Bespoke Cycle Community Interest Company | Wholesale & retail | 2021 |
| Bespoke Indemnity Solutions Ltd | Financial services | 2016 |
| Bespoke Joinery by Miranda Limited | Administrative & support | 2019 |
| Bespoke Kitchens Solutions Limited | Wholesale & retail | 2021 |
| Bespoke Partz Ltd | Wholesale & retail | 2020 |
| Bespoke PT Limited | Arts & recreation | 2024 |
| Bespokes Invest Limited | Administrative & support | 2017 |
| Best Buy Savers Limited | Wholesale & retail | 2026 |
| Best Cafe Ltd | Hospitality | 2018 |
| Best Enfield Ltd | Hospitality | 2025 |
| Best Future Education Ltd | Education | 2017 |
| Best Rendering & Plastering Ltd | Construction | 2026 |
| Bestofbulk Limited | Wholesale & retail | 2024 |
| Betelnut Community Centre CIC | Public administration | 2023 |
| Bethel Supported Living Limited | Health & social care | 2024 |
| Betreat Ltd | Hospitality | 2025 |
| Better Estates Group Ltd | Real estate | 2024 |
| Better Life Mission C.I.C. | Administrative & support | 2025 |
| BEU Scissors Cooperation Ltd | Wholesale & retail | 2024 |
| BEU Scissors Ltd | Wholesale & retail | 2015 |
| Beulah Transport Limited | Other services | 2020 |
| Bexhill Kebab Ltd | Hospitality | 2025 |
| Beyaz Firin Patisserie Ltd | Wholesale & retail | 2022 |
| Beyaztas Motors Ltd | Wholesale & retail | 2026 |
| Beyond Certainty Limited | Administrative & support | 2002 |
| Beyond US Ltd | Arts & recreation | 2023 |
| Beyond Words Therapy Ltd | Health & social care | 2020 |
| Beyto Properties Ltd | Real estate | 2026 |
| BFD Trading Limited | Wholesale & retail | 2022 |
| BG Citizens Advice Limited | Construction | 2020 |
| BG Industry Ltd | Construction | 2017 |
| BH Nails & Spa Limited | Other services | 2017 |
| BH2GROUP Limited | Water & waste | 2023 |
| Bhava Coffee Limited | Hospitality | 2021 |
| BHM Extensions Ltd | Construction | 2021 |
| BHM Investments Limited | Real estate | 2020 |
| Bhora Africa Limited | Arts & recreation | 2017 |
| Biacs Bar Limited | Hospitality | 2023 |
| Bibiotic Limited | Wholesale & retail | 2023 |
| BIC Consultancy Limited | Professional & scientific | 2021 |
| Bicar Electrical Services Limited | Energy | 2014 |
| Bich Hoang Limited | Other services | 2025 |
| Bicknoller Road Limited | Households | 2017 |
| Big & Red Storage Limited | Real estate | 2009 |
| Big Brother's Cafe Limited | Hospitality | 2005 |
| Big Brothers Development Ltd | Construction | 2021 |
| Big Brothers INK Ltd | Wholesale & retail | 2022 |
| Big Close-Up Ltd | Information & communication | 2022 |
| Big Cube Club Ltd | Manufacturing | 2019 |
| Big Datahouse Ltd | Information & communication | 2021 |
| Big Day BID Limited | Information & communication | 2017 |
| Big Doggs Catering Ltd | Wholesale & retail | 2018 |
| Big Rock Property Investment Limited | Financial services | 2023 |
| Big Spoon Kitchen Ltd | Hospitality | 2021 |
| Bigbang Digital Services Ltd | Wholesale & retail | 2019 |
| Bigbasketgroup Ltd | Wholesale & retail | 2022 |
| Bigdataviz Ltd | Other services | 2016 |
| Bilaman H Limited | Professional & scientific | 2011 |
| Bilaman Limited | Financial services | 1989 |
| Bilans Accountancy Limited | Professional & scientific | 2017 |
| Bilgic Engineering Consultancy Ltd | Construction | 2019 |
| Bill's Investments Ltd | Real estate | 2024 |
| Bill's Projects Ltd | Construction | 2020 |
| Billa Drylining Solutions Limited | Construction | 2022 |
| Billingsdale Ltd | Extraterritorial | 2004 |
| Billroy 2 Ltd | Administrative & support | 2024 |
| Billroy Ltd | Administrative & support | 2022 |
| Billy Hair & Beauty Ltd | Other services | 2016 |
| BILO27 Ltd | Hospitality | 2025 |
| BIM Engineers Ltd | Construction | 2015 |
| Bingol Construction Ltd | Construction | 2021 |
| Biobeauty London Ltd | Wholesale & retail | 2024 |
| Biohybrid Restorative Limited | Health & social care | 2024 |
| Biology of Balance Ltd | Health & social care | 2026 |
| Bionano Health and Medical Device Limited | Manufacturing | 2025 |
| Bioo Domestic and Commercial Cleaning Limited | Water & waste | 2011 |
| Bioo Security Limited | Administrative & support | 2017 |
| Bircan Enterprises Ltd | Real estate | 2019 |
| Bishop & Scott Limited | Administrative & support | 2024 |
| Bishop Enterprises Limited | Financial services | 2019 |
| Bisken International Limited | Wholesale & retail | 2023 |
| Bismillahh UK Ltd | Real estate | 2022 |
| Bistro 1 (London) Limited | Hospitality | 2004 |
| Bistro 1 Cheapside Ltd | Hospitality | 2024 |