| Bonded Permanent Jewellery Ltd | Wholesale & retail | 2024 |
| Bondsound Limited | Agriculture & fishing | 1980 |
| Bonny Grove Technical Ltd | Professional & scientific | 2025 |
| Book Your Trade Limited | Wholesale & retail | 2022 |
| Bordello Group Ltd | Wholesale & retail | 2023 |
| Boro Barber Limited | Other services | 2023 |
| Boro Bathrooms & Kitchens Ltd | Construction | 2025 |
| Boro Bites Biryani Limited | Hospitality | 2025 |
| Boro Bites Ltd | Hospitality | 2023 |
| Boro Cabs Limited | Transport & logistics | 2025 |
| Boro Car Sales Limited | Wholesale & retail | 2019 |
| Boro Carpets Ltd | Wholesale & retail | 2016 |
| Boro Cash & Carry Ltd | Wholesale & retail | 2026 |
| Boro Cleaning Services M Ltd | Administrative & support | 2025 |
| Boro Doughnut C.I.C. | Professional & scientific | 2023 |
| Boro IT & Business Solutions Limited | Information & communication | 2013 |
| Boro Mobiles Ltd | Other services | 2020 |
| Boro Nails Spa Ltd | Other services | 2026 |
| Boro News Ltd | Wholesale & retail | 2026 |
| Boro Parmos Ltd | Hospitality | 2025 |
| Boro Pizza Middlesbrough Ltd | Hospitality | 2018 |
| Boro Plants Limited | Agriculture & fishing | 2020 |
| Boro Properties Limited | Real estate | 2013 |
| Boro Protect Security Ltd | Administrative & support | 2021 |
| Boro Real Estate Ltd | Real estate | 2023 |
| Boro Stainless Steel Ltd | Construction | 2022 |
| Boro Tandoori House Ltd | Hospitality | 2025 |
| Boro Trade Ltd | Wholesale & retail | 2025 |
| Boro Travels Ltd | Administrative & support | 2024 |
| Boro Tyres Ltd | Wholesale & retail | 2026 |
| Borobee Ltd | Wholesale & retail | 2023 |
| Borocuda Limited | Education | 2016 |
| Borocuda Teesside Amateur Swimming Club CIC | Education | 2022 |
| Borough Laundry Services Ltd | Other services | 2019 |
| Borough Market a Ltd | Wholesale & retail | 2026 |
| Borshi Ltd | Hospitality | 2023 |
| Bottom Line Business Coaching Ltd | Professional & scientific | 2021 |
| Bottomley Site Services Limited | Administrative & support | 2013 |
| Boulevard 8 Limited | Hospitality | 2017 |
| Bovi-Stop Limited | Agriculture & fishing | 2019 |
| Bovillus Group Ltd | Wholesale & retail | 2025 |
| BOW Energy Limited | Professional & scientific | 2018 |
| Bowdin Electrical Services Ltd | Professional & scientific | 2019 |
| Bowenhole Developments Ltd | Real estate | 2023 |
| Bowers Consultancy Ltd | Administrative & support | 2018 |
| Bowlzz Ltd | Hospitality | 2025 |
| Box Clever Storage Solutions Ltd | Other services | 2005 |
| BOX12 Ltd | Arts & recreation | 2025 |
| Boxcity (NE) Limited | Other services | 2021 |
| BP Middlesborough Ltd | Hospitality | 2025 |
| BP Premium Ltd | Information & communication | 2018 |
| BP Wheatley Electrical Services Limited | Administrative & support | 2013 |
| Bpbrun Ltd | Construction | 2026 |
| BPI Assets Limited | Real estate | 2015 |
| BPJ Case Management Limited | Health & social care | 2021 |
| BPN Transport Limited | Transport & logistics | 2012 |
| BPN UK Limited | Transport & logistics | 2006 |
| BRADLEY5 Ltd | Administrative & support | 2025 |
| Braians Ltd | Wholesale & retail | 2025 |
| Bramble's Farm Social Club Ltd | Hospitality | 2018 |
| Brambles 2023 Ltd | Wholesale & retail | 2023 |
| Brand Box Digital Ltd | Information & communication | 2024 |
| Brand Express Ltd | Wholesale & retail | 2022 |
| Brandwithtom Ltd | Manufacturing | 2025 |
| Brass Castle Country House Ltd. | Hospitality | 2013 |
| Brass Monkey Stokesley Ltd | Wholesale & retail | 2022 |
| Breakout Contractor Services Limited | Administrative & support | 2008 |
| Breckon Hill Community Enterprise | Information & communication | 2008 |
| Breckon Services (NE) Limited | Health & social care | 2016 |
| Breydon Engineering Ltd | Construction | 2025 |
| Brian Barry Hair Salon Limited | Other services | 2015 |
| Brian Noble Fencing Contractors Limited | Administrative & support | 1997 |
| Brian Poole Safety Solutions Ltd | Professional & scientific | 2025 |
| Bricks Lettings Limited | Real estate | 2026 |
| Bridge Green Holdings Ltd | Real estate | 2024 |
| Bright House Motors Limited | Wholesale & retail | 2026 |
| Bright Lights Media Ltd | Information & communication | 2020 |
| Bright Sparks LED Nursery Group Limited | Education | 2016 |
| Brightpath Contact Ltd | Health & social care | 2026 |
| Brightpath Integrated Services Ltd | Information & communication | 2026 |
| Brightside Windows Teesside Ltd | Construction | 2023 |
| Brightside Windows Teesside NE Ltd | Construction | 2026 |
| Brimco Holdings Limited | Financial services | 2024 |
| Brindle Electrical Services Limited | Energy | 2008 |
| Brindles Stokesley Limited | Wholesale & retail | 2025 |
| Brit Card Ltd | Wholesale & retail | 2024 |
| Britannia Biscuits Company (International) Limited | Manufacturing | 2000 |
| Britannia Developments EY Ltd | Construction | 2022 |
| Britannia Fish Shop Limited | Hospitality | 2026 |
| Britannia Housing Limited | Real estate | 2008 |
| Britannia Test & Measurement Limited | Professional & scientific | 2002 |
| Britannia Training Ltd | Education | 1996 |
| British Society of Skeletal Radiologists | Health & social care | 2010 |
| Britsoft Towel Ltd | Wholesale & retail | 2024 |
| Britstay Ltd | Wholesale & retail | 2025 |
| Brituxe Ltd | Wholesale & retail | 2025 |
| Brixso Ltd | Information & communication | 2026 |
| BRM Technical Services Ltd | Professional & scientific | 2025 |
| Broadwater Angling Supplies Limited | Wholesale & retail | 2017 |
| Brombeere LLP | | 2019 |