| Tithe Court Freehold Limited | Real estate | 2000 |
| Tithe Court Management Limited | Real estate | 1995 |
| TJ Mistry Ltd | Professional & scientific | 2022 |
| Tk-Team Limited | Manufacturing | 2007 |
| TKS Consulting Services Ltd | Information & communication | 2016 |
| TLD Property Berkshire Ltd | Real estate | 2023 |
| TLP Routes to Market Limited | Professional & scientific | 2012 |
| TM Care Sevices Limited | Health & social care | 2025 |
| TMB Construction Limited | Construction | 2018 |
| TMB Electrical Limited | Construction | 2006 |
| TMF Filming Limited | Professional & scientific | 2022 |
| TMJ Gardening and Services Limited | Administrative & support | 2023 |
| TMR Roofline Limited | Construction | 2024 |
| TMX Property Services Ltd | Administrative & support | 2022 |
| Tobisco Care Services and Staffing Solutions Ltd | Administrative & support | 2022 |
| Tokalink Limited | Administrative & support | 2012 |
| Tomlin Groundworks Limited | Construction | 2024 |
| Tompikini Limited | Administrative & support | 2010 |
| Tony Bowers Golf Academy Limited | Education | 2014 |
| Tony Correale Autos Ltd | Wholesale & retail | 2010 |
| Top Banana Bouncy Castles Ltd | Arts & recreation | 2017 |
| Top Embroidery Limited | Extraterritorial | 2010 |
| Topik Ltd | Professional & scientific | 2009 |
| Topline PR Ltd | Professional & scientific | 2018 |
| Topperland Co. Ltd | Wholesale & retail | 2010 |
| Tops Scaffolding Ltd | Construction | 2025 |
| Torque International Trade Limited | Wholesale & retail | 2011 |
| Total Beauty Salons Limited | Other services | 2003 |
| Totally Taylored Limited | Professional & scientific | 2025 |
| Totalworld Limited | Administrative & support | 2002 |
| Touchdown Construction Limited | Construction | 2022 |
| Touchdown Group Ltd | Construction | 2020 |
| Touchdown Project Management Limited | Construction | 2022 |
| Touchofcee Ltd | Other services | 2024 |
| Tower Property Lettings Limited | Real estate | 2024 |
| Townsend Casting Limited | Information & communication | 2019 |
| Tp&Co Limited | Transport & logistics | 2025 |
| Trade Box Property Solutions Ltd | Construction | 2018 |
| Trade Sales (Caravans) Ltd | Wholesale & retail | 2025 |
| Tradeline Flooring Trading AS Floorteck Flooring Limited | Wholesale & retail | 2017 |
| Trafalgar 1805 Property Limited | Real estate | 2022 |
| Trafalgar Supply Co Ltd | Wholesale & retail | 2024 |
| Trailfindit Ltd | Information & communication | 2018 |
| Training Services & Solutions Limited | Information & communication | 1998 |
| Transcend Consultants Ltd | Professional & scientific | 2025 |
| Transcrip Limited | Professional & scientific | 2020 |
| Transept Consulting Limited | Transport & logistics | 1998 |
| Transit Tech Services Ltd | Wholesale & retail | 2024 |
| Transonix Ltd | Construction | 2023 |
| Transport and Travel Research Limited | Extraterritorial | 1991 |
| Trauma & Ptsd Centre Limited | Health & social care | 2023 |
| Trauma Training Limited | Education | 2023 |
| Travel Wealth Limited | Administrative & support | 2014 |
| Travel With Sasha Limited | Administrative & support | 2023 |
| Travelaid Ltd | Professional & scientific | 2022 |
| TRB Building Services Limited | Construction | 2016 |
| TRB Contracts Limited | Administrative & support | 2001 |
| Trebor 72 Limited | Professional & scientific | 2009 |
| Trent RE Limited | Energy | 2016 |
| Trestle Group Ltd | Construction | 2020 |
| Trevor Real Estate Limited | Real estate | 2024 |
| Treyarnon Court Management Company Limited | Administrative & support | 1975 |
| TRH Assurance Limited | Professional & scientific | 2014 |
| TRH Consulting Limited | Information & communication | 2024 |
| Triaster Operations Ltd | Professional & scientific | 2018 |
| Tricounty Bike Shop Limited | Wholesale & retail | 2015 |
| Trident Power Cleaning Ltd | Administrative & support | 2021 |
| Trident Restorations Limited | Financial services | 2025 |
| Triia Limited | Financial services | 2025 |
| Trimmania Limited | Wholesale & retail | 1988 |
| Triple Bbbs Smokehouse Ltd | Hospitality | 2018 |
| Triple Dream Ltd | Real estate | 2018 |
| Triple R Opportunities Limited | Professional & scientific | 2021 |
| Trishakti Solutions Ltd | Information & communication | 2026 |
| Triton CS Limited | Professional & scientific | 2014 |
| Triton Real Estate Limited | Real estate | 2024 |
| Triunion Limited | Hospitality | 2023 |
| TRL International Limited | Financial services | 2009 |
| TRL Limited | Professional & scientific | 1995 |
| TRL Software Limited | Information & communication | 2017 |
| Troy Lopez Services Limited | Construction | 2014 |
| Troywest Software Ltd. | Information & communication | 2011 |
| Trucapturephotography Limited | Professional & scientific | 2025 |
| True Entertainment Limited | Hospitality | 2024 |
| True Floors Limited | Construction | 2019 |
| True Nominees Ltd | Administrative & support | 2009 |
| Truehands Care Ltd | Health & social care | 2026 |
| Truly Inspired Coaching and Training Limited | Professional & scientific | 2010 |
| TRY This Teaching Limited | Education | 2024 |
| Tryfeed Limited | Manufacturing | 2015 |
| Tryzip Limited | Wholesale & retail | 1987 |
| TS Operating Services Limited | Information & communication | 2009 |
| TS Site Engineering Ltd | Professional & scientific | 2022 |
| TT Fixer Limited | Construction | 2015 |
| TT Lighting Limited | Construction | 2017 |
| TT Prevention and Protection Fire Consultancy Ltd | Public administration | 2023 |
| Tubos Ltd | Manufacturing | 2009 |
| Tudor Grange Freehold Limited | Households | 2005 |
| Tudor Grange Residents Association Limited | Households | 2000 |
| Tuitiv Ltd | Information & communication | 2025 |