| Axon Services Ltd | Arts & recreation | 2026 |
| Ayen Consulting Ltd | Professional & scientific | 2014 |
| Aylott Autos Limited | Wholesale & retail | 2019 |
| Aylott Motors Limited | Wholesale & retail | 2019 |
| Aysm Catering Limited | Hospitality | 2019 |
| Azbags Limited | Wholesale & retail | 2012 |
| Azimuth Technology (UK) Limited | Manufacturing | 2012 |
| Azuma Restaurant Limited | Hospitality | 2023 |
| B & R Moll International Ltd | Manufacturing | 2010 |
| B & W Solutions (UK) Ltd | Construction | 2015 |
| B a Surfacing Limited | Construction | 2021 |
| B Construction (Essex) Limited | Construction | 2018 |
| B&A Property Maintenance Ltd | Construction | 2026 |
| B&L Carpentry and Construction Ltd | Other services | 2015 |
| B-Plates Ltd | Wholesale & retail | 2024 |
| B-Tech Fire and Security Ltd | Professional & scientific | 2026 |
| B.C. Wood Plant Hire Ltd | Construction | 2022 |
| B.K.S. Imports Limited | Wholesale & retail | 1998 |
| B67 Property Ltd | Real estate | 2026 |
| Babybambi Ltd | Wholesale & retail | 2023 |
| BAD Monkey Express Ltd | Transport & logistics | 2013 |
| Bailey Scaffolding Contractors Ltd | Construction | 2018 |
| Baileys Plumbing and Heating Services Limited | Construction | 2017 |
| BAKED4U Ltd | Hospitality | 2022 |
| Baldwin & Parr Limited | Administrative & support | 2023 |
| Balgores Basildon Limited | Real estate | 2003 |
| Balgores Bodyshops Limited | Wholesale & retail | 2000 |
| Balgores Commercial Finance Limited | Financial services | 2025 |
| Balgores Essex Limited | Real estate | 2006 |
| Balgores Estates Limited | Real estate | 2012 |
| Balgores Financial Services Limited | Financial services | 2025 |
| Balgores Hayes Limited | Real estate | 2005 |
| Balgores Investments Ltd | Real estate | 2012 |
| Balgores Lettings Limited | Real estate | 2007 |
| Balgores London Limited | Real estate | 2016 |
| Balgores Property Services Limited | Real estate | 2002 |
| Balgores Rayleigh Limited | Wholesale & retail | 2014 |
| Balla IT Services PVT Ltd | Information & communication | 2016 |
| BAM-81 Ltd | Wholesale & retail | 2022 |
| Bamu Holdings Limited | Real estate | 2019 |
| Bandarapola Ceylon Company Ltd | Professional & scientific | 1892 |
| Bandie Safe Limited | Wholesale & retail | 2025 |
| Bandsite Properties Limited | Real estate | 2006 |
| Banhambrook Limited | Other services | 2013 |
| Banks and Sons Commercial Ltd | Construction | 2021 |
| Bannerbow UK Limited | Administrative & support | 2021 |
| Bannister Safety Surfacing Ltd | Construction | 2015 |
| BAO Group Limited | Professional & scientific | 2018 |
| Barclay Designs Limited | Professional & scientific | 1990 |
| Bardel Computer Systems Limited | Information & communication | 2003 |
| Bardwood Support Services Limited | Administrative & support | 2015 |
| Barker Financial Ltd | Administrative & support | 2020 |
| Barling Property Services Limited | Construction | 2006 |
| Barnfield Innovations Ltd | Construction | 2019 |
| Barns Industrial Battery Services Limited | Manufacturing | 2009 |
| Barnwell Gardens Limited | Administrative & support | 2016 |
| BAS Arts Index CIC | Arts & recreation | 2023 |
| BAS Build Ltd | Construction | 2018 |
| Basildon Alliance for Social Enterprise Support CIC | Administrative & support | 2023 |
| Basildon and District Local Enterprise Agency Limited | Extraterritorial | 1984 |
| Basildon Catering Equipment Limited | Wholesale & retail | 2021 |
| Basildon Glass Limited | Manufacturing | 2021 |
| Basildon Microwave & Catering Equipment Ltd | Wholesale & retail | 2008 |
| Basildon Street Food Ltd | Hospitality | 2026 |
| Bask & Fetch Limited | Wholesale & retail | 2024 |
| Bathroom Additions Limited | Wholesale & retail | 2002 |
| Battersby Property Services Ltd | Other services | 2023 |
| Battlesbridge Horse and Country Ltd | Wholesale & retail | 2019 |
| Bavmac Ceilings Limited | Construction | 2014 |
| BBT Clearance Ltd | Wholesale & retail | 2026 |
| BCM Productions Ltd | Arts & recreation | 2013 |
| BDG Services Group Limited | Construction | 2023 |
| BE Happy Home Care Ltd | Health & social care | 2021 |
| BE Limitless Years Ltd | Wholesale & retail | 2026 |
| Bear Building (Essex) Ltd | Construction | 2017 |
| Beauchamps Farms Limited | Agriculture & fishing | 1941 |
| Beautiful Minds Therapy & Counselling Services Limited | Health & social care | 2019 |
| Beauty by Soniya Ltd | Other services | 2021 |
| Beauty Supplies North East Limited | Other services | 2025 |
| BEC Security Systems Ltd. | Administrative & support | 2003 |
| Beck Cabinetry Limited | Manufacturing | 2020 |
| Beckingham Designs Limited | Manufacturing | 2008 |
| BEE Checked Ltd | Administrative & support | 2022 |
| Beechenlea Agricultural Limited | Real estate | 2024 |
| Beechenlea Maintenance Limited | Administrative & support | 2009 |
| Beerbelly.Store Limited | Wholesale & retail | 2020 |
| Behavioural Insights Team Solutions Ltd | Professional & scientific | 2017 |
| Bekap Medical Limited | Health & social care | 2016 |
| Belgravia Construction (London) Limited | Construction | 2016 |
| Bella&Bruno K9 Security Ltd | Manufacturing | 2021 |
| Bellingham Chest and Allergy Ltd | Health & social care | 2019 |
| BEN Lane Photos Limited | Professional & scientific | 2015 |
| BEN Mason Therapy Limited | Health & social care | 2022 |
| BEN Meredith Engineering Ltd | Professional & scientific | 2019 |
| BEP Properties Limited | Real estate | 2018 |
| Berry Lane Solutions Ltd | Administrative & support | 2018 |
| Bespoke Sporting Guns Limited | Wholesale & retail | 2024 |
| Bespoke Technical Services Ltd | Professional & scientific | 2011 |
| Best Direct (International) Limited | Wholesale & retail | 2003 |
| Betts Engineering Ltd | Construction | 2023 |