| Barclay Scaffolding Limited | Construction | 2011 |
| Barclay Site Services Limited | Water & waste | 2021 |
| Barefoot Bathrooms Limited | Construction | 2009 |
| Barentis Group Ltd | Professional & scientific | 2026 |
| Barford Education and Training (North East) Limited | Manufacturing | 2001 |
| Bargin Properties Limited | Administrative & support | 2024 |
| Barkat Group Holdings UK Limited | Information & communication | 2025 |
| Barley Design & Build Ltd | Construction | 2023 |
| Barnard Nominees Limited | Professional & scientific | 1988 |
| Barnes IT Solutions Limited | Information & communication | 1999 |
| Barrier Homes Limited | Real estate | 2021 |
| Barrier Roofing Limited | Construction | 2017 |
| Barrington Freight Ltd | Transport & logistics | 2007 |
| Barsec Consultants Limited | Professional & scientific | 2016 |
| Bartas Holdings Limited | Financial services | 2026 |
| Bartholemew Birds & Fish Limited | Other services | 2023 |
| Basildon Borough Enterprises Limited | Financial services | 2020 |
| Basildon Care Ltd | Health & social care | 2022 |
| Basildon Community Transport Service Ltd | Health & social care | 2012 |
| Basildon Express Ltd | Wholesale & retail | 2026 |
| Basildon First Primary Care Network Ltd | Health & social care | 2019 |
| Basildon Haulage Limited | Transport & logistics | 2020 |
| Basildon Makas Ltd | Other services | 2024 |
| Basildon Mind | Health & social care | 2004 |
| Basildon MOT Limited | Wholesale & retail | 2020 |
| Basildon Mot-Uk Ltd | Wholesale & retail | 2024 |
| Basildon NO 1 Ltd | Construction | 2020 |
| Basildon NO 2 Limited | Construction | 2026 |
| Basildon Properties Limited | Real estate | 2016 |
| Basildon Regeneration Partnership LLP | | 2025 |
| Basildon Sandwiches Ltd | Hospitality | 2026 |
| Basildon Side by Side CIC | Public administration | 2021 |
| Basildon Sport & Leisure Club | Arts & recreation | 2014 |
| Basildon Taxis Ltd | Transport & logistics | 2012 |
| Basildon Tiffin Ltd | Hospitality | 2025 |
| Basildon Timber Merchants Limited | Wholesale & retail | 1988 |
| Basildon Wheels Limited | Manufacturing | 2019 |
| Basildon, Billericay and Wickford Council for Voluntary Service | Other services | 2012 |
| Basinique Ltd | Other services | 2025 |
| Bateman (Properties) Ltd | Real estate | 2007 |
| Bateman Motors Limited | Wholesale & retail | 2024 |
| Bateman Real Estate Partners Ltd | Professional & scientific | 2022 |
| Batman Ltd | Hospitality | 2026 |
| Battleswick Fish & Chips Ltd | Hospitality | 2024 |
| Batts UK Limited | Professional & scientific | 2015 |
| Batty Bonds Cleaning Services Limited | Administrative & support | 2016 |
| Baucutt Property Services Ltd | Construction | 2021 |
| Baxgo Limited | Real estate | 2021 |
| Bay Investments Limited | Real estate | 2010 |
| BB (Essex) Limited | Other services | 2024 |
| BB Financial Services (2025) Limited | Professional & scientific | 2025 |
| BB Therapy Limited | Other services | 2025 |
| BB Transporters Ltd | Transport & logistics | 2019 |
| Bbkaeit Management Ltd | Wholesale & retail | 2020 |
| Bbph Properties Limited | Real estate | 2022 |
| BBS Drylining Specialists Limited | Construction | 2017 |
| BBX Essex Limited | Professional & scientific | 2016 |
| BC Consulting Limited | Professional & scientific | 2015 |
| BCM Landscapes & Fencing Ltd | Administrative & support | 2023 |
| BCT Contracting Limited | Construction | 2018 |
| BCW Construction Limited | Construction | 2016 |
| BD2 Ltd | Professional & scientific | 2005 |
| BDB Bargains Ltd | Wholesale & retail | 2025 |
| BDD Ltd | Professional & scientific | 2026 |
| Bdrb Limited | Construction | 2022 |
| BE Logistics Services Ltd | Transport & logistics | 2025 |
| BE8 Ltd | Other services | 2014 |
| Beaglecrest Limited | Real estate | 1983 |
| Beak Interiors Ltd | Construction | 2011 |
| Beambridge Consulting Limited | Professional & scientific | 2017 |
| Beaney Fisheries Ltd | Agriculture & fishing | 2023 |
| Beaney Group Limited | Administrative & support | 2016 |
| Bear JOE Ltd | Real estate | 2020 |
| Bear JSS Ltd | Real estate | 2025 |
| Bearlike Ltd | Professional & scientific | 2023 |
| Beartas Policy Ltd | Professional & scientific | 2017 |
| Beatrice Motivational Hub Limited | Other services | 2025 |
| Beaumont Beds Limited | Wholesale & retail | 1985 |
| Beautiful Bathrooms Installations Limited | Construction | 2021 |
| Beautiful Buys Ltd | Wholesale & retail | 2024 |
| Beautiful Flooring Limited | Extraterritorial | 2009 |
| Beauty and Aesthetics Education Training CIC | Education | 2025 |
| Beauty Luxe Lounge Ltd | Other services | 2024 |
| Beauty Rose Limited | Other services | 2023 |
| Beauty Skills Training (Southend) Limited | Education | 2019 |
| Beautyislifeline Limited | Other services | 2026 |
| Beckett Taylor Group Limited | Real estate | 2021 |
| Becketts Court Limited | Professional & scientific | 1981 |
| Beckwills Cleaning & Support Services Ltd | Administrative & support | 2022 |
| Beckwills Homes Limited | Real estate | 2020 |
| Becoming YOU C.I.C. | Education | 2025 |
| Bedford Education Development Ltd | Administrative & support | 2023 |
| Bedrock Ergonomics Limited | Professional & scientific | 2026 |
| BEE Fittings Limited | Administrative & support | 2006 |
| Beeches Residents Association (Warminster) Limited | Households | 1998 |
| Beeline Financial Services Limited | Financial services | 2023 |
| Beewise With Energy Limited | Wholesale & retail | 2026 |
| Begap Limited | Professional & scientific | 2014 |
| Behind the Bride Ltd | Professional & scientific | 2025 |
| Being Inbusiness Ltd | Professional & scientific | 2010 |