| THE Sidecar Guys Hospitality and Events Ltd | Financial services | 2025 |
| THE Sidecar Guys Ltd | Wholesale & retail | 2021 |
| THE Star Inn (Harbottle) Limited | Hospitality | 2019 |
| THE Tanners Arms (Alnwick) Ltd | Hospitality | 2022 |
| THE Tech Connection Ltd | Information & communication | 2022 |
| THE Thinking Realm Limited | Administrative & support | 2021 |
| THE Tute Bar Pool Hall Ltd | Arts & recreation | 2025 |
| THE Unpackaged Travel Company Limited | Extraterritorial | 2003 |
| THE Video Editing Expert Ltd | Information & communication | 2025 |
| THE Woodshop & Joinery Company Ltd | Manufacturing | 2017 |
| THE Yard Limited | Real estate | 2014 |
| Thegingerveterancustomclothing Ltd | Wholesale & retail | 2025 |
| Themindworx Ltd | Health & social care | 2024 |
| Thermobrite Preformed Markings Limited | Construction | 2019 |
| Thewashhousemorpeth Ltd | Administrative & support | 2023 |
| Thirston Garage Limited | Wholesale & retail | 2008 |
| Thirston Property & Investments Limited | Extraterritorial | 2012 |
| Thistle Soaps Ltd | Manufacturing | 2013 |
| Thompson Group Ltd | Administrative & support | 2004 |
| Thompson Recruitment Limited | Administrative & support | 2014 |
| Thompson Rental Properties Ltd | Real estate | 2021 |
| Thrive Together Training and Coaching Ltd | Professional & scientific | 2022 |
| Thriving Minds for Families Ltd | Education | 2022 |
| Thriving Minds in Education Limited | Education | 2022 |
| Tidycloud Accounting Ltd | Professional & scientific | 2020 |
| Tiger-Lily Cosmetics Ltd | Manufacturing | 2024 |
| Tightpost Limited | Extraterritorial | 2007 |
| TIK TUK Ltd | Transport & logistics | 2023 |
| Tilbury Rose Ltd | Health & social care | 2017 |
| Tiles of the North Ltd | Construction | 2026 |
| Tilia Tree Consultancy Services Ltd | Agriculture & fishing | 2022 |
| TIM Edwards Estates Limited | Administrative & support | 2020 |
| TIM Kain Limited | Information & communication | 2017 |
| Timeguessr Limited | Information & communication | 2024 |
| Tingy Limited | Information & communication | 2007 |
| Tinman Support Limited | Information & communication | 2019 |
| Tiptop Retail Ltd | Wholesale & retail | 2019 |
| TMP Wealth Management Ltd | Professional & scientific | 2020 |
| TMP WM 2024 Ltd | Professional & scientific | 2024 |
| Tmuk Ltd | Administrative & support | 2026 |
| Todburn Cross-Country Hire Limited | Arts & recreation | 2020 |
| Tomjon Limited | Households | 2022 |
| Tonia Holdings Ltd | Real estate | 2018 |
| Top Cat Engineering Ltd | Professional & scientific | 2018 |
| Topsey Turvey Limited | Hospitality | 2003 |
| TOR Strategy & Management Consultants Ltd | Professional & scientific | 2024 |
| Torm Estate Ltd | Households | 2025 |
| Town & Country Tree Surgeons Limited | Administrative & support | 2014 |
| Town Foot Rise Ltd | Construction | 2020 |
| Town Foot Rise Management Company Ltd | Households | 2023 |
| Townfoot Cafe and Bar Ltd | Hospitality | 2026 |
| Trailyo Ltd | Information & communication | 2025 |
| Travel ME Group Ltd | Administrative & support | 2025 |
| Travs PUB Co Limited | Hospitality | 2018 |
| Trewitley OWL Trust | Education | 2006 |
| Triffid Heavy Plant Limited | Construction | 2014 |
| Triroc Limited | Hospitality | 2021 |
| Triskelion Technical Limited | Professional & scientific | 2026 |
| Tritlington Residents Management Ltd | Households | 2015 |
| True North Educational Psychology Ltd | Education | 2022 |
| Trust House Developments Ltd | Construction | 2013 |
| Trusted Mortgage & Equity Release Solutions Ltd. | Financial services | 2023 |
| Trustees Meldon Park Estate Limited | Administrative & support | 2006 |
| TS Holiday Camps Limited | Arts & recreation | 2024 |
| TST Medical Limited | Other services | 2016 |
| TUB Solutions Ltd | Other services | 2022 |
| Tuff Marketing Ltd | Professional & scientific | 2025 |
| Tullys Trading Ltd | Wholesale & retail | 2026 |
| Turk Restaurant Ltd | Hospitality | 2026 |
| Turkish Food (NE) Ltd | Hospitality | 2025 |
| Turn 45 Ltd | Wholesale & retail | 2025 |
| Turnpull Limited | Construction | 2024 |
| Turquoise Blue Recordings Ltd | Arts & recreation | 2010 |
| TW Eason Holdings Ltd | Real estate | 2019 |
| TW Groundworks and Maintenance Limited | Construction | 2026 |
| Twhp Ltd | Real estate | 2025 |
| Twisted Consultants Ltd | Other services | 2009 |
| TWS Engineering Services Limited | Professional & scientific | 2024 |
| Tyne Fire & Safety Limited | Administrative & support | 2015 |
| Tyne View Property Management Ltd | Real estate | 2013 |
| Tyneside Piano Company Limited | Wholesale & retail | 2008 |
| UK Highway Solutions (Transport Services) Limited | Transport & logistics | 2018 |
| Ulgham Farm Management Company Limited | Households | 2010 |
| Ulgham Grange Holidays Ltd | Hospitality | 2023 |
| United Group Travel Ltd | Administrative & support | 2020 |
| Unity Angel Investments Limited | Financial services | 2025 |
| Unity Angels Limited | Administrative & support | 2025 |
| Ushomi Ltd | Information & communication | 2024 |
| Valley View Barns Ltd | Construction | 2023 |
| Valley View Developments Ltd | Construction | 2023 |
| Valley View Garage (Thropton) Ltd | Wholesale & retail | 2023 |
| Valley View Homes NE Ltd | Real estate | 2023 |
| Valley View Simonside Ltd | Construction | 2023 |
| Vape Nectar Ltd | Wholesale & retail | 2019 |
| VC & B Investments Ltd | Administrative & support | 2021 |
| Verdant Golf Ltd | Wholesale & retail | 2026 |
| Verdi Properties Limited | Real estate | 2022 |
| Vertechs Heating Integrations Ltd | Construction | 2012 |
| Veġetali Ltd | Hospitality | 2023 |
| VG Foodstore and Sons Ltd | Wholesale & retail | 2026 |