| Total Communications Partnership Ltd | Extraterritorial | 2013 |
| Total Constructive Group Ltd | Extraterritorial | 2015 |
| Total Constructive Solutions Limited | Construction | 2004 |
| Total FIX & Fit Home Solutions Ltd | Manufacturing | 2025 |
| Total Health Chiropractic Limited | Health & social care | 2022 |
| Total Home Concepts Limited | Construction | 2011 |
| Touchnetics Limited | Manufacturing | 2010 |
| Town Gate Freehold Company Limited | Real estate | 2021 |
| Toywise Limited | Wholesale & retail | 2002 |
| TP Jenner Ltd | Manufacturing | 2026 |
| TP Plastering Contractors Ltd | Construction | 2018 |
| Tpaw Ltd | Wholesale & retail | 2026 |
| TPC Holdings (South) Ltd | Financial services | 2018 |
| TPQ Outdoor Catering Ltd. | Hospitality | 2024 |
| Tpsp (Management) Limited | Construction | 2025 |
| TQS Services Limited | Other services | 2020 |
| Tracey Shaw Limited | Professional & scientific | 2006 |
| Track Monkey Limited | Transport & logistics | 2015 |
| Trackways Rail Limited | Transport & logistics | 2021 |
| Trade Labour Services Limited | Construction | 2016 |
| Trade Sealant Supplies Ltd | Manufacturing | 2025 |
| Tradecraft Tools Limited | Information & communication | 2017 |
| Traditional and Contemporary Bathrooms Ltd | Wholesale & retail | 2019 |
| Trafalgar Property Consultancy Limited | Real estate | 2012 |
| Trafford Carpentry Services Limited | Construction | 2007 |
| Train N Gain Clubs Ltd | Financial services | 2026 |
| Train N Gain Ltd | Arts & recreation | 2020 |
| Train N Gain X Ltd | Arts & recreation | 2026 |
| Training Ship Active | Education | 2016 |
| Trak-D Solutions Ltd | Wholesale & retail | 2025 |
| Transatlantic Logistics Limited | Extraterritorial | 2021 |
| Transforming YOU Limited | Education | 2013 |
| Transition Bathrooms Limited | Construction | 2015 |
| Transition Properties Limited | Construction | 2022 |
| Translate ME Limited | Professional & scientific | 2014 |
| Transparency Task Force Limited | Other services | 2015 |
| Transparent Communications Limited | Wholesale & retail | 2002 |
| Transport and Logistic Support Ltd | Transport & logistics | 2016 |
| Transport Southern Ltd | Transport & logistics | 2025 |
| Transportise Ltd | Water & waste | 2022 |
| Transtec Equipment Ltd | Wholesale & retail | 2011 |
| Traob Limited | Professional & scientific | 2023 |
| Trauma Clinic Group Ltd | Health & social care | 2025 |
| Traveca Lifestyle Services Limited | Wholesale & retail | 2024 |
| Travel Connections Executive Ltd | Transport & logistics | 2010 |
| Treacy's Ltd | Hospitality | 2024 |
| Treasure Trash & Tees Ltd | Water & waste | 2024 |
| Tredegar Healthcare Limited | Professional & scientific | 2010 |
| Tredstone Building Services Ltd | Construction | 2018 |
| Treetops Drive Management Company Limited | Real estate | 2013 |
| Trenchant Management Services Limited | Professional & scientific | 2012 |
| Trendy Nail Ltd | Other services | 2024 |
| Trevio Limited | Information & communication | 2026 |
| Trevor Pearce Projects Ltd | Transport & logistics | 2014 |
| Trevor Wallbridge Financial Services Ltd | Other services | 2017 |
| Tricel (Portsmouth) Limited | Manufacturing | 1987 |
| Tricker Investments Ltd | Real estate | 2024 |
| Tricrown Consults Ltd | Health & social care | 2019 |
| Trilby Shipping Limited | Transport & logistics | 2014 |
| Trinity Commercial Projects Ltd | Construction | 2021 |
| Trio Tea House Limited | Manufacturing | 2011 |
| Triple D Holdings Limited | Real estate | 2024 |
| Triple EYE Properties Limited | Construction | 2016 |
| Triple J Properties Ltd | Real estate | 2019 |
| Trish Wadley Productions Ltd | Arts & recreation | 2018 |
| Tristo Fabrication Ltd | Wholesale & retail | 2025 |
| Triton Investment Holdings Limited | Financial services | 2026 |
| Triton Scuba Ltd | Extraterritorial | 2024 |
| Triumvirate Holdings Ltd | Financial services | 2018 |
| Trivium Construction & Lifting Limited | Administrative & support | 2024 |
| Trophy Car Sales Limited | Wholesale & retail | 2006 |
| Tropizest Ltd | Wholesale & retail | 2016 |
| Trowel Blazers Limited | Construction | 2013 |
| Trubshaws Hair Company Ltd | Other services | 2022 |
| Truck Technology Ltd | Professional & scientific | 2017 |
| True Blue Roofing Limited | Construction | 2023 |
| True Consulting Ltd | Administrative & support | 2022 |
| Truesouth Services Ltd | Construction | 2025 |
| Truleigh Hill Farm Stables LLP | | 2007 |
| Trulora Limited | Administrative & support | 2025 |
| Trushape Investment Casting UK Limited | Manufacturing | 2023 |
| Trustees of the MMO Accountants EOT Limited | Extraterritorial | 2025 |
| Trustees of the Phat Retail EOT Limited | Extraterritorial | 2026 |
| Tryv Nest C.I.C. | Information & communication | 2025 |
| TSM Plumbing & Heating Ltd | Construction | 2026 |
| TTS (Saas) Ltd | Manufacturing | 2025 |
| Tudaisy Studio Ltd | Professional & scientific | 2023 |
| Turnbull Digger Services Limited | Construction | 2014 |
| Turner Services (Salisbury) Ltd | Manufacturing | 2020 |
| Turnquay Build Limited | Construction | 2023 |
| Turvey Construction Limited | Construction | 2003 |
| Turvey Developments Limited | Construction | 2007 |
| Turvey Estates Limited | Financial services | 2017 |
| Turvey Group Limited | Financial services | 2016 |
| TV Scape Ltd | Professional & scientific | 2012 |
| Tvsas Brighton & Portsmouth Ltd | Information & communication | 2007 |
| TWC Services Inc Ltd | Administrative & support | 2011 |
| TWE Services Limited | Wholesale & retail | 2021 |
| Twenty Second Limited | Professional & scientific | 2009 |
| Twenty Something Estates (Timber Yard) Limited | Real estate | 2019 |