| Thinking Money Productions Limited | Professional & scientific | 2003 |
| Thirdway Properties Limited | Real estate | 2005 |
| Thomas Brown Photography Limited | Arts & recreation | 2012 |
| Thomas Wrenn Homes Ltd | Construction | 1984 |
| Thomas. Bergin | | 1998 |
| Thornycroft Court Residents Company Limited | Households | 1962 |
| Thousand Hills Catering Limited | Hospitality | 2000 |
| Three Meadows Mews Management Company Limited | Households | 2003 |
| Thrive Fostering Ltd | Administrative & support | 2024 |
| Tiah Ltd | Wholesale & retail | 2024 |
| Tianna Consulting Limited | Professional & scientific | 2003 |
| Ticbal Limited | Professional & scientific | 2007 |
| Ticketkart Limited | Administrative & support | 2023 |
| Tiger Foods Limited | Wholesale & retail | 1998 |
| Tiger Import Export Limited | Wholesale & retail | 2003 |
| Tiger Investment Solutions Limited | Real estate | 2006 |
| Tile-Connect Limited | Wholesale & retail | 2006 |
| Tilkesh Property Management Ltd | Real estate | 2023 |
| TIM Denyer Limited | Arts & recreation | 2007 |
| Timber Robot Ltd | Arts & recreation | 2015 |
| Timberworks Europe Limited | Construction | 2008 |
| Time Travel Limited | Professional & scientific | 1957 |
| TIME2HEAL Psychotherapy Ltd | Health & social care | 2022 |
| Timesbid Limited | Information & communication | 2000 |
| Timgad Supermarket Limited | Hospitality | 2025 |
| Timothy. Ryan | | 1998 |
| Tinbucket Development Ltd | Construction | 2026 |
| Tinder Limited | Administrative & support | 2006 |
| Tinkers Wood Services Ltd | Administrative & support | 2025 |
| Tinsley & Co.Limited | Wholesale & retail | 1946 |
| TIR Ltd | Professional & scientific | 2023 |
| Tiran Limited | Wholesale & retail | 2024 |
| Tissera Consultants Limited | Professional & scientific | 2003 |
| TLC Group Limited | Health & social care | 1999 |
| TLM South Ltd | Construction | 2006 |
| Tmcl Ltd | Professional & scientific | 2023 |
| Tmok Services Limited | Professional & scientific | 1996 |
| Token House Securities Limited | Real estate | 2003 |
| TOM Flynn Electrical Contractor Limited | Construction | 2003 |
| TOM Wandrag Imaging Limited | Arts & recreation | 2010 |
| Toma Business Enterprises Limited | Construction | 2006 |
| Tomlinvest Limited | Professional & scientific | 1967 |
| Tonbridge Ltd | Real estate | 1999 |
| Tooled UP Limited | Extraterritorial | 2004 |
| Top Star Plumbing Limited | Wholesale & retail | 2024 |
| Topline Accounting & Management Services Ltd | Real estate | 2005 |
| Topmode Investments Limited | Real estate | 1999 |
| Toprise Limited | Construction | 1997 |
| Tops Clothing & Workwear Company Limited | Wholesale & retail | 1995 |
| Topside Park Home Refurbishment Ltd | Construction | 2026 |
| Torn Souls Limited | Information & communication | 2019 |
| Tornado Sports Limited | Wholesale & retail | 2002 |
| Total Consultancy Solutions Limited | Professional & scientific | 2008 |
| Total Debt Recoveries Limited | Professional & scientific | 2005 |
| Total Rental Management Limited | Real estate | 2008 |
| Total Solutions (GB) Limited | Wholesale & retail | 2001 |
| Totteridge Limited | Administrative & support | 2003 |
| Touch & Admire Detailing Ltd | Wholesale & retail | 2026 |
| Touchup Palace Limited | Professional & scientific | 2002 |
| Touchwood Surveyors Limited | Professional & scientific | 2021 |
| Toureen Group Limited | Administrative & support | 2006 |
| Town and County Investment Company Limited | Construction | 1955 |
| TPF (Holdings) Limited | Real estate | 1999 |
| TPM Creative Ltd | Professional & scientific | 2005 |
| TPP Tax Consultancy Limited | Professional & scientific | 2001 |
| Tracker Network (UK) Limited | Administrative & support | 1991 |
| Trade Cars Limited | Wholesale & retail | 2005 |
| Trafalgar Court (Mundesley) Management Company Limited | Households | 1988 |
| Traffic Orders Services Ltd | Administrative & support | 2006 |
| Tram Arts 15 Ltd | Real estate | 2018 |
| Transactor Limited | Construction | 2005 |
| Transcroft Consultancy Limited | Administrative & support | 2005 |
| Transkold Limited | Transport & logistics | 1980 |
| Transnet Systems Limited | Information & communication | 1999 |
| Transxtrade Ltd | Transport & logistics | 2025 |
| Traveasy.Com Limited | Administrative & support | 2004 |
| Travel (U.K.) Limited | Administrative & support | 1993 |
| Travel Around Limited | Administrative & support | 1969 |
| Travel Hub Limited | Administrative & support | 2004 |
| Travel Solutions Ltd | Administrative & support | 2005 |
| Travel Station Ltd | Administrative & support | 2026 |
| Travel Talk Adventures Limited | Administrative & support | 2010 |
| Traxion Consulting Limited | Administrative & support | 2005 |
| Trekland Limited | Real estate | 2005 |
| Trenchco Limited | Construction | 1997 |
| Trenchcon Limited | Professional & scientific | 2005 |
| Trend Harbee Ltd | Wholesale & retail | 2024 |
| Trexus Limited | Information & communication | 1994 |
| TRI Consulting Limited | Administrative & support | 2000 |
| Tricia Power Ltd. | Information & communication | 2001 |
| Trident Refrigeration Limited | Construction | 1981 |
| Triomnia Limited | Real estate | 1999 |
| Triple Edge Limited | Professional & scientific | 2026 |
| Triplehigh Limited | Construction | 1990 |
| Trivion Limited | Information & communication | 2014 |
| Troke News Limited | Wholesale & retail | 2007 |
| Truda Investments Limited | Financial services | 2004 |
| True Goal Consultants Limited | Information & communication | 2017 |
| True Measure Limited | Professional & scientific | 2011 |
| True Smile Digital Dental Laboratory Ltd | Professional & scientific | 2021 |