| Browology Microblading & Spmu Ltd | Professional & scientific | 2023 |
| BRS Travel Solutions Limited | Administrative & support | 2016 |
| Bruk Access & Inspection Services Limited | Professional & scientific | 2019 |
| Bruwer Construction Services Ltd | Construction | 2018 |
| Bryelle Anaesthesia Associates Limited | Health & social care | 2022 |
| Brynley Bond Ltd | Construction | 2026 |
| Bryxter Services Limited | Real estate | 2023 |
| BSV Services Limited | Administrative & support | 2025 |
| BT Hodgeon Logistics Limited | Transport & logistics | 2025 |
| Btgemg Accommodations Ltd | Administrative & support | 2026 |
| Btib Holdings Ltd | Hospitality | 2026 |
| Btsco Limited | Financial services | 2017 |
| Buckland Energy Limited | Professional & scientific | 2025 |
| Budo for Change CIC | Education | 2021 |
| Build Renovate Maintain Ltd | Construction | 2024 |
| Buildeez Ltd | Construction | 2018 |
| Builders Supply Co (Kendal) Limited(The) | Extraterritorial | 1933 |
| Builders.Timeserved Ltd | Construction | 2025 |
| Building and Landscape Solutions Ltd | Construction | 2015 |
| Bulldog Marine & Technical Services Limited | Manufacturing | 2001 |
| Buller Holdings Ltd | Hospitality | 2021 |
| Buma Group Limited | Wholesale & retail | 2026 |
| Burgerlicious NE Ltd | Hospitality | 2026 |
| Burn Terrace Health Limited | Wholesale & retail | 2025 |
| Burrows Property Group Ltd | Real estate | 2022 |
| Burton Building and Plastering Ltd | Construction | 2024 |
| Busby a Limited | Wholesale & retail | 2023 |
| Busby Farm Holdings (Stokesley) Limited | Real estate | 1974 |
| Busby Hand Car Wash Ltd | Administrative & support | 2023 |
| BUSES4SALE Ltd | Transport & logistics | 2006 |
| Busy BEE Bookkeeping Limited | Professional & scientific | 2014 |
| Butler Bros Environmental Solutions Ltd | Water & waste | 2020 |
| Buttercup Learning Ltd | Education | 2020 |
| Buxton Trading Limited | Wholesale & retail | 2026 |
| Buzz & Bloom Ltd | Agriculture & fishing | 2018 |
| BW Software Ltd | Information & communication | 2024 |
| BWN Academy C.I.C. | Information & communication | 2025 |
| BZ Paintball Supplies Limited | Arts & recreation | 2009 |
| C & D Storage Ltd | Transport & logistics | 2022 |
| C & H Inspection Ltd. | Professional & scientific | 2017 |
| C & H Property Ltd | Real estate | 2024 |
| C & M Housing Ltd | Real estate | 2023 |
| C & M Tees Ltd | Health & social care | 2018 |
| C B Services PMC Limited | Other services | 2014 |
| C Bishop Construction Limited | Construction | 2025 |
| C D Electrical Construction Limited | Construction | 2014 |
| C Haste Limited | Energy | 2025 |
| C J Hayes Limited | Professional & scientific | 2015 |
| C L K Technical Services Ltd | Construction | 2010 |
| C L Rigging Services Limited | Construction | 2021 |
| C Stanton Maintenance Services Ltd | Administrative & support | 2013 |
| C&Bmo Ltd | Hospitality | 2023 |
| C&G Property Developments Limited | Construction | 2014 |
| C&J Landscaping Limited | Administrative & support | 2023 |
| C&L Technical Services Limited | Construction | 2022 |
| C&M Home Renovations Ltd | Construction | 2025 |
| C&S Nails Spa Limited | Other services | 2021 |
| C.E.M Technical Services Ltd | Professional & scientific | 2025 |
| C.J.B. Drylining Ltd. | Construction | 2006 |
| C.L. Pounder Limited | Hospitality | 2001 |
| C.L.J Media Ltd | Professional & scientific | 2017 |
| C.R. Kime Limited | Health & social care | 1989 |
| C.S.Rigg Ltd | Construction | 2024 |
| C17 Deli Ltd | Hospitality | 2026 |
| C3SIXTY Ltd | Information & communication | 2017 |
| CA Tyler Logistics Ltd | Transport & logistics | 2025 |
| CAB Glass (Stockton) Limited | Construction | 1969 |
| Cable Network Limited | Wholesale & retail | 2026 |
| Cable Trail Limited | Manufacturing | 2015 |
| Cactus: Business Consultancy Limited | Other services | 2023 |
| CAD Engineering Management Limited | Professional & scientific | 2015 |
| Cadet Stores UK Ltd | Wholesale & retail | 2025 |
| Caesario Logistics Limited | Transport & logistics | 2024 |
| Caesium Security Limited | Professional & scientific | 2024 |
| Cafe NO.6 Ltd | Hospitality | 2022 |
| Cafe Sapore Ltd | Hospitality | 2022 |
| Cain & Fellow Limited | Other services | 2018 |
| Cairlinn Holdings Limited | Financial services | 2020 |
| Cakes & Shakes Ltd | Hospitality | 2019 |
| CAL KEL Properties Limited | Real estate | 2024 |
| Calibyta Ltd | Hospitality | 2014 |
| Calista C Limited | Other services | 2025 |
| Callander Holdings Company Ltd | Professional & scientific | 2025 |
| Callander Mortgage Solutions Ltd | Financial services | 2019 |
| Calum Hedley Transport Ltd | Transport & logistics | 2026 |
| Calve Instruments Ltd | Professional & scientific | 2025 |
| Camden Green Ltd | Construction | 2021 |
| Camperdown Stores Limited | Wholesale & retail | 2005 |
| Camperlife Limited | Arts & recreation | 2015 |
| Canario Ltd | Wholesale & retail | 2024 |
| Candour Comms Ltd | Information & communication | 2022 |
| Candy Bloom Ltd | Wholesale & retail | 2025 |
| Canine Design Stockton Ltd | Other services | 2017 |
| Canteen & Cocktails Ltd | Hospitality | 2014 |
| Capital Grid Design Ltd | Health & social care | 2024 |
| Capstone Project Consultancy Limited | Professional & scientific | 2026 |
| Car Buyers North East Ltd | Wholesale & retail | 2022 |
| Care & Glory Limited | Health & social care | 2014 |
| Care & Support Solutions (North East) Limited | Health & social care | 2011 |
| Care Call 24 Ltd | Health & social care | 2025 |