| BB Developments Essex Limited | Construction | 2021 |
| BBG Aston Ltd | Other services | 2017 |
| BBG Port Limited | Real estate | 2024 |
| BBG Services Limited | Professional & scientific | 2008 |
| BE Sure Building and Maintenance Services Ltd | Construction | 2000 |
| Beacon Branch Education Limited | Financial services | 2023 |
| Beacon Education Limited | Administrative & support | 2002 |
| Beau Bells Ltd | Wholesale & retail | 2025 |
| Beauchamps (Wickford) Residents Company Ltd | Households | 2014 |
| Beaufield Care and Support Ltd | Health & social care | 2026 |
| Beauty Infinity Brides Ltd | Other services | 2023 |
| Beckford Build Ltd | Construction | 2017 |
| Beckford Family Holdings Ltd | Financial services | 2022 |
| Beechhead Limited | Other services | 2016 |
| Beecroft Demolition Ltd | Construction | 2020 |
| Beke Lodge Business Consultants Limited | Professional & scientific | 2004 |
| Believe in Your Business Limited | Professional & scientific | 2012 |
| Bell House Investments Ltd | Real estate | 2006 |
| Bellace Construction Ltd | Construction | 2019 |
| Bellagray Ltd | Health & social care | 2021 |
| Bellame Construction Ltd | Construction | 2019 |
| Bellame Group Ltd | Construction | 2019 |
| Belloak Properties Limited | Real estate | 2007 |
| Bellula Property Ltd | Real estate | 2022 |
| Benchmark Data Solutions (Essex) Limited | Information & communication | 2026 |
| Beni Property Investments Limited | Real estate | 2018 |
| Benton-Newman Properties Limited | Real estate | 2024 |
| Bernie's Besties Limited | Other services | 2026 |
| Berzerker Wargaming Ltd | Construction | 2024 |
| Bespoke Medical Solutions Limited | Professional & scientific | 2015 |
| Bespoke Twenty Four LLP | | 2022 |
| Best Environmental Demolition Limited | Construction | 2023 |
| Best Environmental Solutions Ltd | Water & waste | 2015 |
| Best Kebab (Eastwood) Limited | Hospitality | 2016 |
| Best Kebab (Southend) Limited | Hospitality | 2016 |
| Best Therapies Ltd | Health & social care | 2022 |
| Bethmas Ltd | Information & communication | 2023 |
| Bettawell Ltd | Administrative & support | 2022 |
| Beulah Homes & Properties Limited | Real estate | 2024 |
| Bevel Mounts Limited | Manufacturing | 2008 |
| BFH LR1 Ltd | Real estate | 2026 |
| BFH LR2 Ltd | Real estate | 2026 |
| BG Electrical Services Limited | Construction | 2021 |
| Bhig Investments Limited | Real estate | 2023 |
| Biba-Boys Ltd | Wholesale & retail | 2021 |
| Big Boys Group Limited | Wholesale & retail | 2005 |
| Big Yellow Ribbon Limited | Wholesale & retail | 2009 |
| Bigsy Hair Limited | Other services | 2023 |
| Billy Bond Cutter of Hair Ltd | Other services | 2016 |
| Billy Field Cleaning & Maintenance Services Ltd | Construction | 2019 |
| Billy Marchant Limited | Arts & recreation | 2022 |
| Binder & SON Ltd | Other services | 2015 |
| Binformed Limited | Professional & scientific | 2025 |
| Birchmere Lodge RTM Company Ltd | Households | 2022 |
| Bishop Facades Limited | Construction | 2021 |
| Bistro 8 Ltd | Hospitality | 2019 |
| BJK Electrical Ltd | Construction | 2020 |
| BJR Fortis Holdings Limited | Construction | 2024 |
| Black Label Roofing and Building Limited | Construction | 2015 |
| Blackmore Apparel Limited | Wholesale & retail | 2014 |
| Blackthorn Court Residents Company Limited | Real estate | 2011 |
| Blendfind Property Management Limited | Administrative & support | 1987 |
| Bloom Search Limited | Administrative & support | 2022 |
| Blount Shipping Services Limited | | 1982 |
| BLU Planet Marine Fuels Limited | Professional & scientific | 2014 |
| Blue Cola Limited | Real estate | 2024 |
| Blue MUD Projects Limited | Real estate | 2025 |
| Blue Sky Students Limited | Energy | 2015 |
| Blythe Accountancy Ltd | Professional & scientific | 2022 |
| Bmgk Enterprises Limited | Wholesale & retail | 2026 |
| BMR Asset Investments Limited | Professional & scientific | 2024 |
| Bodatojita Ltd | Wholesale & retail | 2019 |
| Bondzie Capital Ltd | Financial services | 2026 |
| Bondzie Consulting Limited | Professional & scientific | 2006 |
| Bongs and Dongs Ltd | Manufacturing | 2022 |
| Book a DPF Clean Limited | Wholesale & retail | 2025 |
| Booksure Accounting Limited | Professional & scientific | 2012 |
| Boon Studio Ltd | Professional & scientific | 2023 |
| Booths Court Limited | Households | 1998 |
| Bottleshower Ltd. | Wholesale & retail | 2014 |
| Bowers LLP | | 2009 |
| Bowers Promotions Limited | Administrative & support | 2015 |
| Bowers RTM Company Limited | Households | 2014 |
| Bowlerscroft Management Company Limited | Households | 1988 |
| Bowtox Limited | Other services | 2025 |
| Box Finance Limited | Financial services | 2025 |
| Braai Club Limited | Manufacturing | 2019 |
| Braithwaite 123 Limited | Real estate | 2017 |
| Bramley Place Management Company Ltd | Real estate | 2012 |
| Brand Consulting Engineers Limited | Professional & scientific | 1992 |
| Branhurst Finance Limited | Financial services | 1987 |
| Bravo Property Limited | Real estate | 2014 |
| Break Away Demolition Ltd | Construction | 2023 |
| Brennan Heating & Plumbing Limited | Construction | 2021 |
| Brentwood Solar Limited | Construction | 2023 |
| Briarsford Panelcraft Ltd. | Wholesale & retail | 1980 |
| Brickhouse Restaurant UK Limited | Hospitality | 2022 |
| Bridge Electrical Solutions Limited | Construction | 2019 |
| Bridge Thermal Insulation Limited | Construction | 2019 |
| Bright Media & Marketing Ltd | Professional & scientific | 2009 |