| BEN Charles Durham F.S. Limited | Financial services | 2009 |
| BEN Charles Durham Limited | Real estate | 2009 |
| BEN Goad Barber Limited | Other services | 2026 |
| BEN Taylor Property Ltd | Real estate | 2019 |
| BEN Willis Limited | Wholesale & retail | 2025 |
| Benchmark Control Ltd | Manufacturing | 2015 |
| Benchmark Electronics Test and Assemble Ltd | Manufacturing | 2019 |
| Benidorm and Beyond Ltd | Information & communication | 2023 |
| Benis Pizzeria Ltd | Hospitality | 2025 |
| Benridge Horsebox Hire Limited | Transport & logistics | 2024 |
| Benun Ltd | Administrative & support | 2024 |
| Berjan Trade Ltd | Wholesale & retail | 2025 |
| Berry Fitness Ltd | Wholesale & retail | 2014 |
| Bespoke Bathroom Designs Limited | Wholesale & retail | 2021 |
| Bespoke Homewares Ltd | Other services | 2018 |
| Bespoke Roofing & Developments Ltd | Construction | 2025 |
| Best Kebab (Durham) Ltd | Hospitality | 2025 |
| Best Kebab North Limited | Hospitality | 2021 |
| Bethea IVY Limited | Health & social care | 2012 |
| Bethell & Co Limited | Professional & scientific | 2021 |
| Better Living Outdoors Limited | Construction | 2015 |
| Betty Bee's Limited | Hospitality | 2018 |
| Bewick Mobility Limited | Wholesale & retail | 2004 |
| Bexben Properties Ltd | Real estate | 2024 |
| Beyond Co Group Limited | Financial services | 2024 |
| Beyond Leisure Limited | Hospitality | 2002 |
| Beyond the Goal Ltd | Wholesale & retail | 2025 |
| BH Joinery NE Ltd | Construction | 2025 |
| Bhsm Holdings Ltd | Financial services | 2026 |
| Biddible Media Ltd | Professional & scientific | 2015 |
| Big Babki Ltd | Wholesale & retail | 2025 |
| Big Bang Books Limited | Wholesale & retail | 2016 |
| Big Box Products Ltd | Manufacturing | 2019 |
| Big Little Toys Limited | Wholesale & retail | 2015 |
| Big Mama Secreit Delicious Ltd | Hospitality | 2025 |
| Big Red Engineering Limited | Construction | 2017 |
| Big Sister Care Limited | Health & social care | 2025 |
| Big World Recovery Ltd | Health & social care | 2024 |
| Biggen Haulage Ltd | Transport & logistics | 2006 |
| Billingham Junior Ice Hockey Club Ltd | Arts & recreation | 2020 |
| BIM Property Development Limited | Construction | 2011 |
| Binks Engineering and Design Limited | Professional & scientific | 2017 |
| Biofuel Energy Ltd | Wholesale & retail | 2021 |
| Bioplo Ltd | Administrative & support | 2026 |
| Bird Island I.S.A Ltd | Wholesale & retail | 2025 |
| Bishop Property Sourcing Ltd | Real estate | 2024 |
| Bishopbek Hall Residents Company Limited | Households | 2017 |
| Bishops Court (Shincliffe) Management Company Limited | Households | 1993 |
| Bistro Citron Vert Ltd | Hospitality | 2015 |
| Bitola E-Commerce Ltd | Wholesale & retail | 2025 |
| BJL Drylining Ltd | Construction | 2026 |
| BK168 Ltd | Hospitality | 2021 |
| Bksw Ltd | Professional & scientific | 2021 |
| Black Dog Promotions Limited | Professional & scientific | 2025 |
| Black Jade Publishing Limited | Information & communication | 2019 |
| Black Muir Properties Limited | Real estate | 2025 |
| Black Sheep Education Ltd | Education | 2026 |
| Black Thread Marketing Limited | Professional & scientific | 2025 |
| Blackgate Leisure Limited | Wholesale & retail | 1998 |
| Blackgate Security Group Ltd | Administrative & support | 2026 |
| Blacksmiths Properties Ltd | Real estate | 2022 |
| Blackwell Grange JV Limited | Real estate | 2022 |
| Blaire's Pet Pantry Limited | Wholesale & retail | 2025 |
| Blakk Rose Management Ltd | Professional & scientific | 2025 |
| Blaydon Car & Van Sales Ltd | Wholesale & retail | 2025 |
| Blinking Buzzard Limited | Hospitality | 2017 |
| Blossoming Phoenix Limited | Other services | 2025 |
| Blot Outdoors Show Ltd | Information & communication | 2023 |
| BLU Properties Limited | Real estate | 2011 |
| Blue Clover Group Ltd | Wholesale & retail | 2025 |
| Blue COW Holdings Limited | Real estate | 2022 |
| Blue EYE Management and Training Ltd | Hospitality | 2025 |
| Blue FOX Software Limited | Information & communication | 2025 |
| Blue Sky Developments (N.E.) Limited | Construction | 2006 |
| Blue Square Holdings Ltd | Real estate | 2021 |
| Bluecom Services Limited | Information & communication | 2024 |
| Blueline Distribution Ltd | Wholesale & retail | 2022 |
| Bluengineering Limited | Construction | 2014 |
| Bluepace (Durham) Limited | Real estate | 2012 |
| Bluewater Inns Limited | Hospitality | 2017 |
| BM Ultra Ltd | Wholesale & retail | 2007 |
| BMB Contracts & Civils Ltd | Construction | 2026 |
| BMS Property Holdings Ltd | Other services | 2020 |
| BMU Ltd | Construction | 2026 |
| BNF Barbers Limited | Other services | 2026 |
| Boathouse Lane (Freehold) Limited | Real estate | 2011 |
| Boathouse Lane Projects Limited | Real estate | 2010 |
| Bodytech NE Ltd | Wholesale & retail | 2024 |
| Boja Limited | Hospitality | 2022 |
| Bolton Abbey Trout Hatchery Limited | Agriculture & fishing | 2025 |
| Bolun 8 Ltd | Hospitality | 2021 |
| Bonanza Consultation UK Ltd | Professional & scientific | 2021 |
| Bonded Agency Limited | Professional & scientific | 2021 |
| Bondoc Commerce Ltd | Wholesale & retail | 2026 |
| Boniplas Limited | Wholesale & retail | 2018 |
| Boomchang Records Ltd | Information & communication | 2023 |
| Border Construction Limited | Construction | 1960 |
| Borfort Property Ltd | Real estate | 2014 |
| Borgo Homes Ltd | Construction | 2022 |
| Borrage Hall Management Company Limited | Households | 2006 |