| Bateman Structural Design Limited | Professional & scientific | 2026 |
| Batir Global Ltd | Construction | 2020 |
| Batt Bros MOT & Servicing Limited | Wholesale & retail | 2013 |
| Batth Developments Ltd | Real estate | 2023 |
| Bay Brick Tiles Ltd | Construction | 2021 |
| Bayley INK Limited | Information & communication | 2011 |
| Bayleyland LLP | | 2005 |
| Bayt AL Zayn Limited | Wholesale & retail | 2025 |
| Bazooka and Co. Ltd | Real estate | 2017 |
| BB Photography Limited | Professional & scientific | 2023 |
| BBA Consult Ltd | Construction | 2021 |
| BBE Consulting Limited | Real estate | 2010 |
| Bbmb Limited | Real estate | 2025 |
| BBP Hair & Beauty Limited | Other services | 2018 |
| BCS Drylining Ltd | Construction | 2021 |
| BD Property Limited | Real estate | 2018 |
| BDA Engineering Limited | Professional & scientific | 2025 |
| BDB Management Solutions Ltd | Professional & scientific | 2014 |
| Bdsgdrinks Limited | Hospitality | 2025 |
| BE ALL Coaching Limited | Other services | 2019 |
| Beaconstone Projects Ltd | Construction | 2025 |
| Beanbag Solutions Ltd | Information & communication | 2026 |
| Bear Property Group Limited | Real estate | 2020 |
| Bear Property Sourcing Limited | Real estate | 2018 |
| Beauty 247 Ltd | Other services | 2025 |
| Beauty FOX Clinic Ltd | Other services | 2021 |
| Beauty Studio Images Ltd | Other services | 2015 |
| Beaver Research Ltd | Professional & scientific | 2019 |
| Because of YOU Ltd | Wholesale & retail | 2016 |
| Becca Ironing Limited | Other services | 2013 |
| Beckenham Management Services Limited | Hospitality | 2025 |
| Becs Spiritual Medium Limited | Other services | 2025 |
| Bed-Watch Limited | Health & social care | 2023 |
| BEE Wise Day Nurseries Ltd | Health & social care | 2023 |
| Beech House Services Limited | Administrative & support | 2024 |
| Beech Management Company (Hornchurch) Limited | Households | 2007 |
| Beehive Tuition Services Ltd | Education | 2015 |
| Beetle Consulting Limited | Information & communication | 2013 |
| Belbatt Ltd | Wholesale & retail | 2019 |
| Bellalex Limited | Financial services | 2022 |
| Bellamy Fire Ltd | Administrative & support | 2021 |
| Bellassilvers Limited | Health & social care | 2012 |
| Belle BOO Limited | Arts & recreation | 2024 |
| Belle Couronne Ltd | Wholesale & retail | 2023 |
| Bellingan Limited | Health & social care | 2012 |
| Belmont House (Hornchurch) Residents Association Limited | Real estate | 1974 |
| Belu Property Limited | Real estate | 2022 |
| BEN and Charlie's Bakery Ltd | Manufacturing | 2021 |
| BEN and Chris Limited | Wholesale & retail | 2022 |
| BEN Duckett Limited | Arts & recreation | 2017 |
| BENGAL220 Ltd | Hospitality | 2023 |
| Benhurst Financial Ltd | Financial services | 2021 |
| Benjamin Intelligence Limited | Professional & scientific | 2025 |
| Benson Plumbing Ltd | Construction | 2005 |
| Beralius Accounts Ltd | Information & communication | 2010 |
| Bergh I.T. Limited | Information & communication | 2001 |
| Bernie Conroy Consulting Limited | Professional & scientific | 2017 |
| Bespoke London Ltd | Manufacturing | 2016 |
| Best Consulting UK Ltd | Construction | 2018 |
| Best Health Protect Limited | Financial services | 2009 |
| Best Lider Limited | Hospitality | 2026 |
| Best Real Estate UK Ltd | Real estate | 2025 |
| Besthaven Limited | Construction | 1974 |
| Betaj Solutions Limited | Information & communication | 2016 |
| Bettafi Limited | Information & communication | 2025 |
| Better Care for YOU Ltd | Health & social care | 2025 |
| Better Life Community Initiative Ltd | Financial services | 2025 |
| Betterbespoke Ltd | Construction | 2017 |
| BETTY1929 Limited | Financial services | 2025 |
| Beverly Marks Stage School Limited | Arts & recreation | 1999 |
| Beyond Bright Ltd | Administrative & support | 2026 |
| Beyond Consultancy Limited | Professional & scientific | 2020 |
| Beyoutify Limited | Wholesale & retail | 2024 |
| Bez-Kin Expo Ltd | Wholesale & retail | 2021 |
| Bez-Kin Medical Ltd | Wholesale & retail | 2022 |
| BFL Homes Ltd | Real estate | 2019 |
| BH Transport Limited | Transport & logistics | 2026 |
| Bhangu Haulage Ltd. | Transport & logistics | 2015 |
| Bhogal Property Development Ltd | Real estate | 2025 |
| Bhuiyan Global Group Ltd | Manufacturing | 2025 |
| Bhuna & Biryani Limited | Hospitality | 2025 |
| Bhuutech Construction Limited | Construction | 2015 |
| Bhuutech Property Ltd | Real estate | 2020 |
| Bianca Tutoring Services Ltd | Education | 2023 |
| Big Boss (London) Limited | Wholesale & retail | 1993 |
| BIGGIEWEST02 Ltd | Administrative & support | 2021 |
| Bike DR Ltd | Wholesale & retail | 2024 |
| Bike Enterprises Limited | Information & communication | 2010 |
| Billington Estate Management Limited | Extraterritorial | 2014 |
| Billionair Bitcoin Club Ltd | Information & communication | 2020 |
| Bimssfood Ltd | Wholesale & retail | 2024 |
| Binaryrange Limited | Information & communication | 2009 |
| Binaz Ltd | Wholesale & retail | 2010 |
| Bindu Childcare Services Ltd | Education | 2014 |
| Bingo Electrical Ltd | Construction | 2021 |
| BIO Europa Ltd | Wholesale & retail | 2020 |
| Biodent-Uk Limited | Health & social care | 2025 |
| Bioinfinity Ltd | Wholesale & retail | 2015 |
| Biolexis Ltd | Professional & scientific | 2024 |
| Biotalk Limited | Professional & scientific | 1998 |