| Total Rope Access Solutions Ltd | Manufacturing | 2026 |
| Total Stag and HEN Ltd | Administrative & support | 2013 |
| Total Transmission Ltd | Construction | 2026 |
| Totalcare Property Solutions Ltd | Construction | 2025 |
| Totally Polished Nails and Beauty Ltd | Other services | 2024 |
| Totally Polished Training Academy Ltd | Education | 2024 |
| Totally Transformed Limited | Other services | 2020 |
| Tots ARE US Ltd | Health & social care | 2024 |
| Tots to Teams Limited | Manufacturing | 2003 |
| Toucan Education Ltd | Education | 2016 |
| Toucan Education Services Ltd | Education | 2020 |
| Tough Life Products Limited | Administrative & support | 2021 |
| Tough Love Gym Ltd | Arts & recreation | 2025 |
| Tourist Coaches Limited | Professional & scientific | 1995 |
| TOW & Leisure Ltd | Professional & scientific | 2011 |
| Towerburn View (Shilbottle) Management Company Limited | Real estate | 2025 |
| Towerco Limited | Construction | 1979 |
| Town FRY Express Ltd | Administrative & support | 2018 |
| Town Moor Visual Arts CIC | Arts & recreation | 2025 |
| Town Square (Management) Limited | Real estate | 2003 |
| Townhouse Morpeth Ltd | Hospitality | 2024 |
| Townmoore Property Partners Ltd | Real estate | 2019 |
| Townsend Watson Associates Ltd | Professional & scientific | 2026 |
| Towton Productions Limited | Information & communication | 2016 |
| Toys for ALL Ltd | Wholesale & retail | 2025 |
| TPD RB Limited | Extraterritorial | 2014 |
| TPH Health Solutions Ltd | Professional & scientific | 2020 |
| TPS E&P International Ltd | Wholesale & retail | 2024 |
| TPS Estates Ltd | Construction | 2025 |
| TR Management Services Limited | Real estate | 2012 |
| Tr@Kubelaw Limited | Administrative & support | 2024 |
| Traced Solutions Limited | Administrative & support | 2026 |
| Tracey Nixon Health and Safety Services Ltd | Public administration | 2014 |
| Tracey Watson Coaching Ltd | Administrative & support | 2015 |
| Track and Field Sports Limited | Wholesale & retail | 2005 |
| Track Personnel Ltd | Administrative & support | 2022 |
| TRACK7 Technology Group Limited | Financial services | 2025 |
| TRACK7 Ventures Limited | Information & communication | 2025 |
| Trade Car Parts Ltd | Wholesale & retail | 2023 |
| Trade Carpets Limited | Wholesale & retail | 1997 |
| Trade Deck Ltd | Wholesale & retail | 2022 |
| Trade Generator Limited | Information & communication | 2020 |
| Tradebar Ltd | Wholesale & retail | 2025 |
| Traderoot International Ltd | Information & communication | 2019 |
| Trades Abode Ltd. | Hospitality | 2023 |
| Trading Aurum Limited | Wholesale & retail | 2025 |
| Trading Bridge Ltd | Administrative & support | 2025 |
| Trading Circle Limited | Wholesale & retail | 2014 |
| Trafalgar Design (UK) Limited | Information & communication | 2010 |
| Traffic Management Support Solutions Ltd | Construction | 2023 |
| Train Air Ltd | Professional & scientific | 2020 |
| Train Fitness Limited | Information & communication | 2013 |
| Traincon Learning Limited | Education | 2017 |
| Training and Development Resource Limited | Education | 1996 |
| Training and Safety Assurance Ltd | Professional & scientific | 2008 |
| Training Vision (Traivis) Ltd | Information & communication | 2021 |
| Traitor Lips and Equine Skies Ltd | Wholesale & retail | 2025 |
| Tralek Ltd | Real estate | 2016 |
| Tramonto Vans Ltd | Manufacturing | 2025 |
| Transact AR Ltd | Information & communication | 2025 |
| Transactacar Ltd | Wholesale & retail | 2019 |
| Transaction Services Group Limited | Financial services | 2015 |
| Transcend Bloodstock Limited Liability Partnership | | 2004 |
| Transcendent Cards Ltd | Wholesale & retail | 2022 |
| Transferswithease Limited | Administrative & support | 2013 |
| Transfiguration ARK Revival Ministry Ltd | Health & social care | 2024 |
| Transform Development Solutions Ltd | Construction | 2019 |
| Transformational Learning Ltd | Education | 2024 |
| Transforming Business Through Talent Ltd | Professional & scientific | 2020 |
| Transit Logistics Ltd | Manufacturing | 2017 |
| Transit Specialist Ltd | Wholesale & retail | 2023 |
| Transnational Films Ltd | Information & communication | 2018 |
| Transport Compliance Associates Limited | Professional & scientific | 2017 |
| Transport for Patients Limited | Wholesale & retail | 2025 |
| Transport Solutions Consultants Limited | Professional & scientific | 2016 |
| Transserv UK Limited | Financial services | 2013 |
| Trap Food House Ltd | Hospitality | 2020 |
| Trapeze Creative Limited | Arts & recreation | 2012 |
| Travel Northeast Ltd | Transport & logistics | 2020 |
| Travelbuzz Limited | Administrative & support | 2009 |
| Traveller and Gypsy Support Community Interest Company | Health & social care | 2025 |
| Travellers Rest Belmont Limited | Hospitality | 2026 |
| Travelrn Limited | Health & social care | 2023 |
| Travixo Limited | Wholesale & retail | 2026 |
| Travona Limited | Administrative & support | 2002 |
| Traxion.Gg Limited | Professional & scientific | 2024 |
| TRE Colore 149 Limited | Hospitality | 2025 |
| Treadan Ltd | Real estate | 2023 |
| Treasure Express 2 Limited | Professional & scientific | 2004 |
| Treat-Nmd Alliance Ltd | Professional & scientific | 2019 |
| Treat-Nmd Services Ltd | Professional & scientific | 2019 |
| Treb Ltd | Manufacturing | 2020 |
| Trebor Electrical Ltd | Professional & scientific | 2024 |
| Tree Shake Investments Ltd | Financial services | 2021 |
| Trees, Logs & Gardens Ltd | Construction | 2025 |
| Treetops Wallsend Management Limited | Real estate | 2004 |
| Trend Bible Limited | Professional & scientific | 2011 |
| Trend Retail Ltd | Wholesale & retail | 2024 |
| Trend Trace Ltd | Wholesale & retail | 2017 |
| Trendlistr Ltd | Wholesale & retail | 2016 |