| Banner House Repair & Decor Ltd | Construction | 2025 |
| Bar Loco Limited | Hospitality | 2019 |
| Bargain Tiles Darlington Limited | Wholesale & retail | 2012 |
| Barista Sisters Limited | Hospitality | 2016 |
| Barkers Investments Ltd | Real estate | 2024 |
| Barkers Property Ltd | Real estate | 2022 |
| Barmet Limited | Professional & scientific | 2017 |
| Barmpton Engineering Limited | Professional & scientific | 2024 |
| Barmpton Motor Company Limited | Wholesale & retail | 2021 |
| Barnabas Ltd | Health & social care | 2025 |
| Barnard Castle Container Storage Limited | Transport & logistics | 2026 |
| Baroness Homes Northern Limited | Hospitality | 2023 |
| Barrett Brothers Ltd | Wholesale & retail | 2024 |
| Bart&B Limited | Transport & logistics | 2015 |
| Barton GAS Services Limited | Construction | 2021 |
| Barton Plumbing & Heating Limited | Construction | 2018 |
| Barton Property Solutions Limited | Households | 2025 |
| Bartram Advisory Ltd | Professional & scientific | 2026 |
| Bath & Shower Works Ltd | Construction | 2022 |
| BAU Innenraum Limited | Construction | 2017 |
| Bawarish Group Limited | Information & communication | 2025 |
| Bawarish Limited | Health & social care | 2016 |
| Baxter Hairdressing Ltd | Other services | 2012 |
| Baybreeze Bathrooms Limited | Administrative & support | 2024 |
| Baydale Beck Limited | Hospitality | 2012 |
| Baydale Control Systems Limited | Construction | 1999 |
| Baydale Croft (Management) Limited | Households | 2000 |
| Baydale Croft (Management) NO.2 Limited | Extraterritorial | 2000 |
| Baydale Estates Limited | Real estate | 2004 |
| Bazas Barber Ltd | Other services | 2025 |
| Bazzar Store Limited | Wholesale & retail | 2025 |
| BBA North East Limited | Construction | 2024 |
| BBC 454 Limited | Hospitality | 2022 |
| Bbsm Transport Ltd | Transport & logistics | 2026 |
| BC Roofing Northeast Ltd | Construction | 2024 |
| BC Webster Limited | Education | 2026 |
| BC24 Group Ltd | Financial services | 2024 |
| BCM Logistics Ltd | Transport & logistics | 2015 |
| BCS Property Projects Limited | Construction | 2017 |
| Bcsl Holdings Limited | Professional & scientific | 2004 |
| BCW Collective Limited | Other services | 2026 |
| BD Analytics Ltd | Information & communication | 2021 |
| BD Safety Services Limited | Administrative & support | 2025 |
| BD Supplies (Darlington) Limited | Construction | 2019 |
| BDA Partnership Limited | Professional & scientific | 2016 |
| BE Premiere Limited | Other services | 2018 |
| Beacon Care Group Ltd | Health & social care | 2022 |
| Beanies the Flavour Co. Ltd. | Manufacturing | 2011 |
| Bear Couriers & Removals Ltd | Transport & logistics | 2024 |
| Bear Couriers Ltd | Transport & logistics | 2019 |
| Bear Technics Ltd | Professional & scientific | 2024 |
| Beast Mode AGI Ltd | Information & communication | 2026 |
| Beatmatch Limited | Information & communication | 2016 |
| Beaufort Residents Association (Phase II) Limited | Households | 2004 |
| Beaufort Residents Association Limited | Households | 2004 |
| Beaumont Academy Ltd | Education | 2024 |
| Beaumont and Angus Construction Limited | Construction | 2022 |
| Beaumont and Partners 002 Limited | Real estate | 2019 |
| Beaumont and Partners 003 Limited | Real estate | 2020 |
| Beaumont and Partners 004 Limited | Construction | 2020 |
| Beaumont and Partners 005 Ltd | Hospitality | 2021 |
| Beaumont and Partners 006 Ltd | Real estate | 2021 |
| Beaumont and Partners 007 Ltd | Construction | 2021 |
| Beaumont and Partners 008 Ltd | Construction | 2021 |
| Beaumont and Partners 009 Ltd | Real estate | 2022 |
| Beaumont and Partners 010 Ltd | Construction | 2022 |
| Beaumont and Partners 011 Ltd | Construction | 2022 |
| Beaumont and Partners 012 Ltd | Construction | 2022 |
| Beaumont and Partners 013 Limited | Construction | 2022 |
| Beaumont and Partners 014 Ltd | Real estate | 2022 |
| Beaumont and Partners 015 Ltd | Real estate | 2022 |
| Beaumont and Partners 016 Ltd | Real estate | 2023 |
| Beaumont and Partners 017 Ltd | Real estate | 2023 |
| Beaumont and Partners 018 Limited | Real estate | 2024 |
| Beaumont and Partners 019 Limited | Real estate | 2024 |
| Beaumont and Partners Development Services Ltd | Construction | 2022 |
| Beaumont and Partners Ltd | Real estate | 2019 |
| Beaumont Lettings and Property Management Limited | Households | 2022 |
| Beaumont RB Holdings Limited | Construction | 2022 |
| Beaumont Refurbs Ltd | Construction | 2021 |
| Beauty by Laura Ltd | Other services | 2024 |
| Beautybyreiss Ltd | Other services | 2026 |
| Bedale Flooring Limited | Wholesale & retail | 2014 |
| Beech Street Management Company Limited | Households | 2007 |
| Beechfield Care & Support Limited | Health & social care | 2009 |
| Beer Sniffers Ltd | Wholesale & retail | 2018 |
| Beeskimming Ltd | Wholesale & retail | 2019 |
| Beijing Palace Restaurant Limited | Hospitality | 2005 |
| Bein Alqutbein International Co. Ltd | Wholesale & retail | 2025 |
| Belah Court Residents Company Limited | Real estate | 2009 |
| Belal Alkhouli Trading Ltd | Wholesale & retail | 2025 |
| Believeyou Community Interest Company | Hospitality | 2021 |
| Bell Blue Limited | Construction | 2015 |
| Bell Community Care Limited | Health & social care | 2015 |
| Bella Bambini Boutique Ltd | Wholesale & retail | 2020 |
| Belle VUE Court Residents Association Limited | Real estate | 1998 |
| Bellevue Civil Ltd | Construction | 2022 |
| Bellotud Limited Ltd | Transport & logistics | 2026 |
| BEN Griffiths Farriers Limited | Other services | 2011 |
| Ben's Plants Ltd | Wholesale & retail | 2025 |