| B. Alliston Limited | Professional & scientific | 2022 |
| B.C.C. (NE) Limited | Manufacturing | 2004 |
| B.H Hospitality NE Limited | Hospitality | 2024 |
| B.H.Leisure Company Limited | Hospitality | 2023 |
| B.M. Stafford & Sons Ltd | Transport & logistics | 2007 |
| B.S.A. Publications Limited | Information & communication | 1976 |
| BA Utilities Ltd | Construction | 2020 |
| BAB UL Hawaij Ltd | Transport & logistics | 2026 |
| Babar's International Ltd | Wholesale & retail | 2025 |
| Baby Sensory Stockton Ltd | Education | 2022 |
| Babylon Vaping Ltd | Wholesale & retail | 2024 |
| Background Sounds Ltd | Manufacturing | 2020 |
| Badturtle Ltd | Wholesale & retail | 2022 |
| Bahou Consultancy Ltd | Professional & scientific | 2023 |
| Bahou Property Ltd | Real estate | 2023 |
| Bahrami Leisure Limited | Real estate | 2000 |
| Bailey Capital Investment Group Limited | Real estate | 2021 |
| Bainbridge Building & Maintenance Ltd | Construction | 2014 |
| Bainbridge Engineering Consultants Ltd | Professional & scientific | 2023 |
| Bainbridge Fresh Produce Ltd. | Wholesale & retail | 2017 |
| Bake With Kaish Ltd | Wholesale & retail | 2026 |
| Baked Technology Ltd | Information & communication | 2012 |
| Baker Tactical UK Ltd | Wholesale & retail | 2025 |
| Balmoral Consulting Ltd | Information & communication | 2020 |
| Balmoral Kennels Company Limited | Other services | 2017 |
| Balnex Ltd | Wholesale & retail | 2026 |
| Bamboo Viet Ltd | Hospitality | 2021 |
| Bambra Limited | Professional & scientific | 2021 |
| Bamma Construction Limited | Construction | 2020 |
| Banks Brothers Transport Limited | Transport & logistics | 1982 |
| Banks Developments Limited | Professional & scientific | 2003 |
| Banks Group Holdings Limited | Professional & scientific | 2018 |
| Banks Homes Limited | Construction | 2022 |
| Banks Property Limited | Real estate | 1995 |
| Banks Renewable Energy Limited | Energy | 2008 |
| Banks Sustainable Living Limited | Professional & scientific | 2009 |
| Banks Waste Limited | Professional & scientific | 2003 |
| Barkers Brickwork Ltd | Construction | 2026 |
| Barking Blends Ltd | Hospitality | 2019 |
| Barlow & Thompson Properties Limited | Real estate | 2021 |
| Barnes-Martin-Foster Limited | Real estate | 2025 |
| Barno Commercials Ltd | Wholesale & retail | 2026 |
| Barnsett Grange Management Company Limited | Households | 2010 |
| Barrds Limited | Financial services | 2023 |
| Barrier Traffic Management Limited | Administrative & support | 2014 |
| Barron Bros Ltd | Construction | 2018 |
| Barry Swailes Limited | Professional & scientific | 2018 |
| Bartoli Europe Ltd | Professional & scientific | 2025 |
| Barwick Aromas Limited | Wholesale & retail | 2023 |
| Basak Commerce Ltd | Wholesale & retail | 2025 |
| Based Consultancy Ltd | Professional & scientific | 2025 |
| Basely Technologies Ltd | Information & communication | 2026 |
| Bate Inspection & Consulting Ltd | Professional & scientific | 2025 |
| Bathrooms North East Limited | Construction | 2024 |
| Batrich Ltd | Real estate | 2024 |
| Battered and Fried Ltd | Hospitality | 2019 |
| Batuhan Serin Ltd | Wholesale & retail | 2025 |
| Bayacademy Limited | Wholesale & retail | 2011 |
| Baza's Barber Durham Ltd | Other services | 2026 |
| BB Energy Limited | Professional & scientific | 2023 |
| BB Grup Limited | Wholesale & retail | 2021 |
| BCJ Property Management Ltd | Real estate | 2022 |
| BCL GAS Service and Repair Limited | Other services | 2018 |
| BE Younique Ltd | Administrative & support | 2017 |
| Be&Ce Store Ltd | Wholesale & retail | 2025 |
| Beach Commercial Property Limited | Hospitality | 2003 |
| Beacon 21 Ltd | Professional & scientific | 2021 |
| Beacon TM Limited | Transport & logistics | 2014 |
| Beaks and Bobbins Ltd | Wholesale & retail | 2018 |
| Beal Cooper Compliance Ltd | Professional & scientific | 2025 |
| Beamex Electrical Limited | Construction | 2014 |
| Bear Bottom Durham Ltd | Wholesale & retail | 2013 |
| Beauty & Aesthetics Training NE Limited | Education | 2024 |
| Beauvy Ltd | Education | 2023 |
| Becca Wilson Aesthetics Ltd | Health & social care | 2021 |
| Beclaxy Limited | Wholesale & retail | 2019 |
| Beda Draughting Limited | Professional & scientific | 2007 |
| Bede Employee Benefit NO.1 Limited | Professional & scientific | 2000 |
| Bede Employee Benefit NO.2 Limited | Professional & scientific | 2000 |
| Bede Group Investments Limited | Real estate | 2019 |
| Bede House Limited | Financial services | 2022 |
| BEE Associates Limited | Administrative & support | 2012 |
| Beech Park Convenience Store Ltd | Wholesale & retail | 2025 |
| Beehive Bathrooms Ltd | Wholesale & retail | 2020 |
| Beep Beep Cars Ltd | Wholesale & retail | 2023 |
| Beep Beep Service Centre Ltd | Wholesale & retail | 2025 |
| Beer Drop Ltd | Hospitality | 2021 |
| Behind the Curtain (BTC) Community Interest Company | Health & social care | 2023 |
| Believe Solutions Limited | Professional & scientific | 2013 |
| Bell Orthotics Ltd | Manufacturing | 2016 |
| Bellamy and Birch Ltd | Professional & scientific | 2024 |
| Bellmac Fire and Security Limited | Administrative & support | 2017 |
| Belly Corporation Limited | Hospitality | 2021 |
| Belmont Collectables Ltd | Wholesale & retail | 2021 |
| Belmont Greengrocers Limited | Wholesale & retail | 2026 |
| Belmont Handyman Services Ltd | Other services | 2024 |
| Belmont Super News Ltd | Wholesale & retail | 2010 |
| Belmont Tandoori (Durham) Ltd | Hospitality | 2024 |
| Belmont Tandoori 2024 Limited | Hospitality | 2024 |
| Belta Branding Ltd | Professional & scientific | 2024 |