| Tilesheds Stables Limited | Arts & recreation | 2020 |
| Timbers Property Ltd. | Real estate | 2017 |
| Ting 90 Ltd | Hospitality | 2018 |
| Tipit Global Limited | Information & communication | 2026 |
| Tisho Limited | Wholesale & retail | 2024 |
| Tivoli Properties Limited | Construction | 2013 |
| TJN Lifting Operations Ltd | Manufacturing | 2024 |
| TL Consultancy NE Ltd | Professional & scientific | 2025 |
| TM Designs Studio Ltd | Professional & scientific | 2024 |
| Tmmcgeary Ltd | Transport & logistics | 2026 |
| TMZ Foods Ltd | Hospitality | 2025 |
| Tnei Ltd | Education | 2026 |
| Tobeo Ltd | Information & communication | 2025 |
| Tobermory Healthcare Holdings Limited | Wholesale & retail | 2022 |
| Tobisin Property Investor Ltd | Real estate | 2019 |
| Together WE Will CIC | Education | 2025 |
| Toluite Global Limited | Wholesale & retail | 2023 |
| Toney Minchella Limited | Hospitality | 2011 |
| Tony's Convenience Store Limited | Wholesale & retail | 2020 |
| Tony's Holding Company Limited | Financial services | 2026 |
| Tony's Pet and Garden Supplies Limited | Wholesale & retail | 2018 |
| Top Glass Window Cleaners Ltd | Administrative & support | 2019 |
| Top Hair CUT Ltd | Administrative & support | 2017 |
| Top Shop Food & Booze Limited | Wholesale & retail | 2018 |
| Top-Spec Coating Ltd | Professional & scientific | 2024 |
| Total Entertainment and Media Limited | Arts & recreation | 2022 |
| Total Labelling Solutions Limited | Manufacturing | 2005 |
| Total Weed Control NE Ltd | Administrative & support | 2021 |
| Tougan Limited | Professional & scientific | 2016 |
| Towler Tech Ltd | Information & communication | 2018 |
| Town Tech Ltd | Wholesale & retail | 2026 |
| TPA Connect Ltd | Professional & scientific | 2021 |
| TPB Barbers Ltd | Other services | 2026 |
| Trade Discounts Ltd | Wholesale & retail | 2025 |
| Trade Ingredients Ltd | Wholesale & retail | 2021 |
| Trading Ideal Limited | Other services | 2017 |
| Trafalgar Builders N.E. Ltd | Construction | 2024 |
| Trajan Healthcare Ltd | Wholesale & retail | 2023 |
| Trantech Ltd | Construction | 2020 |
| Travel GBR Limited | Wholesale & retail | 2026 |
| Travel Isii Limited | Wholesale & retail | 2025 |
| Travel Island Deals Ltd | Administrative & support | 2024 |
| Trevor Bell Advisory Service Limited | Education | 2006 |
| Trevor Burn Fencing Limited | Professional & scientific | 2003 |
| Trident Subsea Ltd | Professional & scientific | 2026 |
| Trimmers Arms South Shields Limited | Hospitality | 2024 |
| Trinity Mews (IV) Management Company Limited | Households | 1994 |
| Trinity South Residents Management Company Limited | Real estate | 2014 |
| TRM (GB) Limited | Arts & recreation | 2003 |
| Troy King Consultancy Limited | Professional & scientific | 2017 |
| True Connection NE Community Interest Company | Health & social care | 2023 |
| Trueloam Organics Ltd | Wholesale & retail | 2026 |
| TS Engineering Solutions Ltd | Professional & scientific | 2024 |
| Tsymco Ltd | Administrative & support | 2012 |
| TTS Solutions Ltd | Professional & scientific | 2020 |
| TTS Worldwide Ltd | Wholesale & retail | 2012 |
| Turkuaz South Shields Ltd | Hospitality | 2017 |
| Turkuisine Takeaway Limited | Hospitality | 2017 |
| Turnbull GAS Services Ltd | Construction | 2023 |
| Turnbull Marine Services Ltd | Manufacturing | 2018 |
| Turnbull Vending Services Ltd | Wholesale & retail | 2025 |
| Turton's Removals and Storage Ltd | Transport & logistics | 2021 |
| Tutexa Ltd | Information & communication | 2018 |
| Twentyman Court Management Company Limited | Hospitality | 1990 |
| Twin Rigg Services Limited | Administrative & support | 2016 |
| Two Rivers Studio Ltd | Professional & scientific | 2026 |
| Two TEW Managing Company Ltd | Households | 2007 |
| Tyne and Wear Cars Ltd | Transport & logistics | 2023 |
| Tyne and Wear Creative Culture Community Interest Company | Education | 2025 |
| Tyne and Wear Electrical Ltd | Construction | 2024 |
| Tyne and Wear Heating Ltd | Construction | 2025 |
| Tyne and Wear Marine Limited | Transport & logistics | 2015 |
| Tyne Coatings Ltd | Construction | 2019 |
| Tyne DOC Ltd | Hospitality | 2022 |
| Tyne Hospitality Ltd | Hospitality | 2026 |
| Tyne Interiors Limited | Construction | 2020 |
| Tyne Logistics Company Limited | Transport & logistics | 1990 |
| Tyne Lucky Limited | Hospitality | 2020 |
| Tyne Slipway & Engineering Co Limited | Extraterritorial | 2015 |
| Tyne Slipways Limited | Extraterritorial | 2015 |
| Tyne Storage Limited | Transport & logistics | 2024 |
| Tyne Tech Solutions Ltd | Information & communication | 2025 |
| Tyne Tees Frame and Finish Ltd | Construction | 2026 |
| Tyne Tees Security Limited | Administrative & support | 2010 |
| Tynedale Family Funeral Directors Limited | Other services | 2011 |
| Tynegrain Agriculture Limited | Agriculture & fishing | 1982 |
| Tyneholme Community Interest Company | Arts & recreation | 2011 |
| Tyneside Driveways Solutions Ltd | Construction | 2023 |
| Tyneside Early Education Limited | Education | 2011 |
| Tyneside Inspection Services Ltd | Professional & scientific | 2024 |
| Tyneside Nutrition Limited | Manufacturing | 2018 |
| Tyneside Pharmaceuticals Ltd | Health & social care | 2026 |
| Tyneside Transport Ltd | Transport & logistics | 2025 |
| Tyrehq Limited | Wholesale & retail | 2026 |
| U&I CUT Ltd | Other services | 2022 |
| Ubique Offshore Ltd | Mining & quarrying | 2026 |
| UK Docks Limited | Extraterritorial | 2015 |
| UK Docks Marine Services Limited | Extraterritorial | 2015 |
| UK Docks Marine Services North Limited | Manufacturing | 1977 |
| UK Docks Marine Services Teesside Limited | Manufacturing | 2011 |