| BEK Events Ltd | Hospitality | 2021 |
| BEK Investments Limited | Financial services | 2018 |
| Beladoma Limited | Real estate | 2019 |
| Belgy Property Services Limited | Real estate | 2013 |
| Bellaim Consult Ltd | Information & communication | 2018 |
| Bellano Financial Contracts Limited | Administrative & support | 2003 |
| Bellew Construction Limited | Construction | 2015 |
| Belleza Beauty Limited | Other services | 2011 |
| Bellis Investment Group Limited | Real estate | 2021 |
| Bells Digital Hub Limited | Wholesale & retail | 2026 |
| Bellvue Properties Limited | Construction | 2016 |
| Belmont Green Funding 1 Limited | Financial services | 2016 |
| Belmont Green Funding 3 Limited | Financial services | 2016 |
| Belmont Green Funding 4 Limited | Financial services | 2017 |
| Belmont Green Funding 5 Limited | Financial services | 2018 |
| Belto Limited | Hospitality | 2022 |
| Belu London Ltd | Construction | 2023 |
| Bemtec Ltd | Other services | 2023 |
| Ben-Barnes Labour Services Ltd | Construction | 2021 |
| Ben-Barnes Property Investments Ltd | Real estate | 2025 |
| Ben-Barnes Property Services Ltd | Construction | 2017 |
| Bena Profinish Ltd | Manufacturing | 2026 |
| Benfleet Vehicle Services Limited | Wholesale & retail | 2013 |
| Beni C Construction Ltd | Construction | 2024 |
| Benin Union of United Kingdom Ltd | Education | 2020 |
| Benmigabhealth Limited | Extraterritorial | 2022 |
| Bennamann Energy Limited | Wholesale & retail | 2019 |
| Bennamann Ltd | Professional & scientific | 2012 |
| Bennamann Services Ltd | Professional & scientific | 2016 |
| Bennett Transport Limited | Transport & logistics | 2006 |
| Bensallyafful Limited | Construction | 2022 |
| Benson Electrics Limited | Construction | 2018 |
| Bentalls Business Park Basildon Limited | Administrative & support | 2007 |
| Bentos Lettings Ltd | Real estate | 2023 |
| Beon Solutions Ltd | Construction | 2016 |
| Beoretro AV Ltd | Wholesale & retail | 2024 |
| Beps Technology Limited | Professional & scientific | 2020 |
| Beracahh Limited | Health & social care | 2025 |
| Bereket Cafe Ltd | Hospitality | 2025 |
| Berkeley Carter Limited | Professional & scientific | 2020 |
| Berlesduna Academy Trust | Education | 2016 |
| Bernicia Capital Limited | Financial services | 2026 |
| Berriblue Ltd | Professional & scientific | 2016 |
| Berts Candles Ltd | Manufacturing | 2026 |
| Berzinje Ltd | Transport & logistics | 2025 |
| Beshbuld Ltd | Construction | 2017 |
| Bespoke Carving & Joinery Ltd | Construction | 2022 |
| Bespoke Ceilings & Walls (Essex) Limited | Construction | 2024 |
| Bespoke Ceilings & Walls Limited | Construction | 2019 |
| Bespoke Crafts Joinery Limited | Manufacturing | 2025 |
| Bespoke Design and Building Ltd | Construction | 2018 |
| Bespoke Handrails & Staircases Ltd | Construction | 2015 |
| Bespoke Joinery Creations Ltd | Construction | 2016 |
| Bess Global Capital Investment Limited | Professional & scientific | 2016 |
| Best Choice International Limited | Transport & logistics | 2018 |
| Best Clean 4YOU Ltd | Wholesale & retail | 2011 |
| Best Cleaning Team Gold Ltd | Transport & logistics | 2015 |
| Best in Jobs Limited | Information & communication | 2020 |
| Best in Move Limited | Real estate | 2023 |
| BEST4U Motors Ltd | Wholesale & retail | 2016 |
| Bestcase Plastering Ltd | Construction | 2025 |
| Bestel Limited | Real estate | 2021 |
| Bestjiff Ltd | Information & communication | 2022 |
| Bestmals Limited | Professional & scientific | 2021 |
| Bethel Experience Limited | Health & social care | 2018 |
| Bethel Medix Limited | Health & social care | 2023 |
| Better Call Sparky Limited | Construction | 2025 |
| Bettinson Properties Ltd | Real estate | 2025 |
| Betty's Bubbles Ltd | Hospitality | 2018 |
| Beverly Hills International Ltd | Wholesale & retail | 2006 |
| Bewig Integrated Services Limited | Health & social care | 2019 |
| Bexley Sand & Ballast Company Limited | Wholesale & retail | 1961 |
| Bexley Space Limited | Real estate | 2022 |
| Beyond Your Dreams Ltd | Wholesale & retail | 2021 |
| BFC Laindon Ltd | Hospitality | 2023 |
| BFE Fencing Limited | Construction | 2015 |
| BG Premier Bathrooms & Plumbing Limited | Construction | 2024 |
| BG Trading Ltd | Wholesale & retail | 2020 |
| BGB Group Limited | Construction | 2017 |
| BGD Connect Ltd | Transport & logistics | 2025 |
| BGH Scaffolding Limited | Construction | 2013 |
| Bgs&D Limited | Construction | 2025 |
| BH Electrical (Essex) Limited | Energy | 2017 |
| Bhanam IT Consultancy Limited | Information & communication | 2016 |
| Bheb Shalom Limited | Financial services | 2013 |
| BHL Building & Construction Ltd | Construction | 2020 |
| BHS Tech Ltd | Information & communication | 2026 |
| Bibby Bespoke Interiors Limited | Construction | 2018 |
| Biblioteca RO Junior UK Ltd | Wholesale & retail | 2020 |
| Big BAN Ltd | Health & social care | 2018 |
| Big Buzz Ltd | Arts & recreation | 2025 |
| Big Stuff Designs Limited | Construction | 1994 |
| Big Top (Basildon) Ltd | Real estate | 2026 |
| Big Top Self Storage Limited | Wholesale & retail | 2024 |
| Biggsj Ltd | Construction | 2023 |
| Bigman Johnson Ltd | Health & social care | 2025 |
| Bigsteps Children Home Ltd | Health & social care | 2026 |
| Bike to Basics Limited | Manufacturing | 2015 |
| Bikes and Cars AP Ltd | Wholesale & retail | 2018 |
| Bilcon Electrical Limited | Construction | 2015 |