| THR33 SIST3RS Ltd | Hospitality | 2024 |
| Threads and Stitches Ltd | Professional & scientific | 2024 |
| THREE60 3804 Ltd | Real estate | 2023 |
| Thrive Play Cafe CIC | Education | 2026 |
| Through the Woods Well-Being Service CIC | Health & social care | 2024 |
| Thursby Property Limited | Real estate | 2019 |
| Tibbett Holdings Ltd | Professional & scientific | 2026 |
| Tide and Treasure Ltd | Real estate | 2025 |
| Tides of Change Community Interest Company | Education | 2019 |
| Tiger Energy Consultants Limited | Professional & scientific | 2023 |
| Tiger Filtration Limited | Manufacturing | 2004 |
| Tilbury Maintenance & Repairs Ltd | Construction | 2025 |
| Timberline-Roe Limited | Agriculture & fishing | 2012 |
| Time to Shine (North East) CIC | Health & social care | 2023 |
| Timec 1484 Limited | Construction | 2014 |
| Timec 1740 Limited | Real estate | 2020 |
| Timec 1742 Limited | Extraterritorial | 2021 |
| Timec 1777 Limited | Extraterritorial | 2021 |
| Timec 1778 Limited | Extraterritorial | 2021 |
| Timec 1779 Limited | Extraterritorial | 2021 |
| Timec 1843 Limited | Extraterritorial | 2023 |
| Timmey Limited | Construction | 2023 |
| Tinklex Construction Ltd | Construction | 2023 |
| Tinnisburn Windfarm Limited | Energy | 2011 |
| Tinnisburn Windfarm Partnership LLP | | 2011 |
| Titan Construction Limited | Construction | 2021 |
| Titan UK Properties Ltd | Hospitality | 2025 |
| Titann Sports Ltd. | Wholesale & retail | 2025 |
| Tithe Foods Limited | Hospitality | 2023 |
| Tiva+ Ltd | Education | 2012 |
| TJ & M Properties Ltd | Real estate | 2025 |
| TJ Glass and Glazing Services Co Ltd | Manufacturing | 2015 |
| TJM@ UK Ltd | Administrative & support | 2017 |
| TKA Engineering Limited | Professional & scientific | 2016 |
| TKS Prime Limited | Wholesale & retail | 2026 |
| TM Edge Ltd | Wholesale & retail | 2025 |
| TM ITS Limited | Administrative & support | 2016 |
| TMG Properties (NE) Ltd | Construction | 2026 |
| TMS Tube Manipulation Services Ltd | Manufacturing | 2022 |
| TND Nails Ltd | Other services | 2025 |
| TNS NE Ltd | Construction | 2024 |
| TNT Nails and Beauty Limited | Other services | 2024 |
| Tobbell Engineering Solutions Ltd | Professional & scientific | 2022 |
| Together for Children Sunderland Limited | Public administration | 2016 |
| Tojan Limited | Manufacturing | 2006 |
| Tokki Mgmt Ltd | Hospitality | 2025 |
| Tolz Kitchen Limited | Hospitality | 2024 |
| TOM Distribution Ltd | Wholesale & retail | 2024 |
| Tomafood Ltd | Information & communication | 2025 |
| Tombaera Limited | Health & social care | 2018 |
| Tommy Blades Limited | Other services | 2022 |
| Tonek Properties Ltd | Real estate | 2025 |
| Tony Clarke Funeral Directors (Hylton House) Ltd | Other services | 2015 |
| Tony Clarke Funerals Limited | Other services | 2024 |
| Tony Dover Limited | Professional & scientific | 2012 |
| Toolbox Admin Ltd | Administrative & support | 2024 |
| Top African Food Store Ltd | Wholesale & retail | 2013 |
| Top African Shop Ltd | Wholesale & retail | 2019 |
| Top Cuts Sunderland Ltd | Other services | 2025 |
| Top Dog Media Limited | Professional & scientific | 2019 |
| Top HAT Property Ltd | Real estate | 2018 |
| Top Quality Cars Auto Ltd | Wholesale & retail | 2026 |
| Top Vision Academy Limited | Education | 2024 |
| Tophouse Consultancy Ltd | Professional & scientific | 2017 |
| Topical Services Ltd | Administrative & support | 2018 |
| Topspec Decoration Limited | Construction | 2011 |
| Torab Limited | Information & communication | 2025 |
| Tornoe Ltd | Hospitality | 2023 |
| Torus Torus Studios Ltd | Wholesale & retail | 2023 |
| Tosca Parklane Ltd | Hospitality | 2025 |
| Tosca Sunderland Ltd | Hospitality | 2019 |
| Total Commissioning Services Limited | Professional & scientific | 2004 |
| Total Machinery Safety Limited | Professional & scientific | 2025 |
| Total Schoolwear Ltd | Extraterritorial | 2019 |
| Total Sport North East Limited | Wholesale & retail | 2006 |
| Totalfix Property Solutions Ltd | Construction | 2025 |
| Totally Drag Ltd | Education | 2019 |
| Tough's Commercial Contracts Limited | Transport & logistics | 2020 |
| Towards ALL One Ltd | Administrative & support | 2025 |
| Tower GM Ltd | Construction | 2017 |
| Town and Country Cleans Limited | Administrative & support | 2022 |
| Town END Farm Barber Ltd | Other services | 2025 |
| Town END Farm Development Limited | Construction | 2016 |
| Town END Flavours Ltd | Hospitality | 2025 |
| Toynbee Cleaning Services Ltd | Administrative & support | 2004 |
| TP Nail and Spa Ltd | Other services | 2026 |
| TP PLG Ltd | Hospitality | 2026 |
| TPG Lets Ltd | Real estate | 2021 |
| TPI Solutions Ltd | Information & communication | 2018 |
| TR Properties & Lettings Ltd | Real estate | 2024 |
| TR UK Property Ltd | Real estate | 2024 |
| Trade Access Scaffolding Ltd | Construction | 2019 |
| Trade Imports Limited | Manufacturing | 2025 |
| Trade Parts North East Ltd | Wholesale & retail | 2018 |
| Tradeflix Limited | Wholesale & retail | 2015 |
| Trades Web Studio Limited | Information & communication | 2025 |
| Tradewinds Equestrian Limited | Arts & recreation | 2010 |
| Train to BE (North East) Community Interest Company | Other services | 2017 |
| Training 4 Retrofit Ltd | Professional & scientific | 2020 |
| Trand on Ltd | Wholesale & retail | 2026 |