| THE Northumbrian Gorsedd CIC | Education | 2020 |
| THE Nurture Project CIC | Agriculture & fishing | 2022 |
| THE Old Glasses Shop Ltd | Wholesale & retail | 2012 |
| THE Old North Limited | Information & communication | 2017 |
| THE Original Property Company LLP | | 2013 |
| THE OX Inn Ltd | Hospitality | 2019 |
| THE Pizza Coven Ltd | Hospitality | 2026 |
| THE Really Smart Energy Company Ltd | Professional & scientific | 2026 |
| THE Refill Station Ltd | Wholesale & retail | 2020 |
| THE Rewards Hotel Ltd | Hospitality | 2025 |
| THE Riverside Kitchen Chollerford Ltd | Hospitality | 2023 |
| THE Samling Arts Trading Company Limited | Professional & scientific | 1994 |
| THE Sea Chef Limited | Hospitality | 2015 |
| THE Sporty Llama Ltd | Wholesale & retail | 2019 |
| THE Station Inn Hexham Ltd | Hospitality | 2015 |
| THE Street Diner Ltd | Hospitality | 2018 |
| THE Surplus Furnishings Company Limited | Wholesale & retail | 2024 |
| THE Surplus Stock Company Limited | Extraterritorial | 2007 |
| THE Travelling Chippy Ltd | Wholesale & retail | 2026 |
| THE Vindolanda Trust | Arts & recreation | 2014 |
| THE Weightman Group (NE) Ltd | Real estate | 2023 |
| THE Wentworth (Hexham) Ltd | Hospitality | 2011 |
| THE Wishaw Plantation LLP | | 2024 |
| Theatre Sans Frontieres Limited | Arts & recreation | 1991 |
| Themeattic Group Limited | Professional & scientific | 2016 |
| Themeattic Limited | Professional & scientific | 2016 |
| Theosophia Ltd | Education | 2023 |
| Theukhighstreet.Com Ltd | Information & communication | 2000 |
| Think Energy (North East) Ltd | Energy | 2018 |
| Third Iteration Limited | Professional & scientific | 2014 |
| Three Tynes Limited | Arts & recreation | 2025 |
| Thumbs UP Oriental Ltd | Hospitality | 2021 |
| Tidesmith Ltd | Professional & scientific | 2025 |
| Tilia Property UK Limited | Real estate | 2020 |
| TIM Dalton Construction Limited | Construction | 2023 |
| TIM Jackson Editorial Services Limited | Information & communication | 2003 |
| Timber Plant & Haulage Ltd. | Agriculture & fishing | 1999 |
| Timberpak Limited | Water & waste | 2000 |
| Tindle Bros.Limited | Real estate | 1964 |
| TIP Top Digital Ltd | Financial services | 2019 |
| Tipsytiger Ltd | Professional & scientific | 2023 |
| TM Property Development Services Ltd | Real estate | 2017 |
| Toby Pipeline Services Limited | Administrative & support | 2025 |
| TOM Gaisford Fencing Limited | Manufacturing | 2005 |
| Top Guys Barbers Ltd | Other services | 2026 |
| Top Signs (Holdings) Limited | Financial services | 2025 |
| Top Signs Ltd | Manufacturing | 2006 |
| Top Signs Workwear Limited | Manufacturing | 2020 |
| Topping Holdings Limited | Financial services | 2025 |
| Towertop Limited | Real estate | 1998 |
| Town Farm (Wall) Limited | Agriculture & fishing | 1997 |
| Tracks 4 YOU Limited | Manufacturing | 2016 |
| Trades Office Limited | Information & communication | 2026 |
| Transcend Chare Limited | Financial services | 2023 |
| Transcend Hair Limited | Other services | 2023 |
| Transition Tynedale Limited | Administrative & support | 2012 |
| Travelscape Limited | Real estate | 2007 |
| Tree Beard Tree Surgery Limited | Agriculture & fishing | 2022 |
| Trent Park Mini Golf Ltd | Arts & recreation | 2016 |
| Trevap Homes Limited | Construction | 2024 |
| Trevor Hignett Body Repair Centre Limited | Wholesale & retail | 2010 |
| TRI Properties NE Limited | Real estate | 2025 |
| True North Event Logistics Limited | Other services | 2012 |
| Tudor Court (Liverpool) Management Company Limited | Administrative & support | 2018 |
| Turbinia Ltd | Professional & scientific | 2020 |
| Twenty First Century Herbs Ltd | Manufacturing | 2018 |
| Two Ventures Limited | Professional & scientific | 2014 |
| TY Bell Welding & Steel Fabrications Ltd | Professional & scientific | 2025 |
| Tyne Valley Coaches Limited | Transport & logistics | 1967 |
| Tyne Valley Ices Property Ltd | Real estate | 2025 |
| Tynedale Agricultural Society Ltd | Other services | 2006 |
| Tynedale Business Centre Ltd | Real estate | 1986 |
| Tynedale Craft Exchange Limited | Arts & recreation | 2026 |
| Tynedale Golf Club Limited | Arts & recreation | 2026 |
| Tynedale Hospice at Home | Health & social care | 1993 |
| Tynepunk Limited | Information & communication | 2022 |
| Tynerede Accountancy (Haltwhistle) Ltd | Professional & scientific | 2021 |
| Ubiquihex Ltd | Information & communication | 2022 |
| UK Cyber Cluster Collaboration (UKC3) Community Interest Company | Other services | 2021 |
| UK Executives Limited | Professional & scientific | 2001 |
| Unalan Barber Services Ltd | Other services | 2019 |
| Unboxed Community Ltd | Education | 2024 |
| Unity Health Care Solutions Ltd | Health & social care | 2020 |
| UP Front Hexham Limited | Administrative & support | 2016 |
| Upcite Ltd | Wholesale & retail | 2021 |
| Urauree Ltd | Hospitality | 2024 |
| Urban Field Events Limited | Arts & recreation | 2013 |
| Usermatics Ltd. | Information & communication | 2014 |
| V.G. Grevett Limited | Real estate | 1979 |
| Valais Blacknose Society Ltd | Other services | 2020 |
| Vallum Security Solutions Ltd | Administrative & support | 2025 |
| Vamos Vans Ltd | Wholesale & retail | 2021 |
| Veiros Ltd | Wholesale & retail | 2025 |
| Vercelli Restaurant 2017 LLP | | 2017 |
| Verdal (UK) Ltd | Professional & scientific | 2012 |
| Verycivilengineers.Com Ltd | Professional & scientific | 2012 |
| VICT25 Ltd | Hospitality | 2025 |
| Victoria ORR Coaching Ltd | Professional & scientific | 2022 |
| Village Lanterne Ltd | Wholesale & retail | 2013 |
| VIR Thinktank Ltd | Education | 2013 |