| Team Mrlc Limited | Wholesale & retail | 2025 |
| Team Recruitment (Poole) Limited | Administrative & support | 2004 |
| Team RJN Ltd | Wholesale & retail | 2021 |
| Team Valley Leisure Limited | Hospitality | 2022 |
| Teamvis Ltd | Information & communication | 2025 |
| Teamwhite Limited | Wholesale & retail | 2025 |
| Teamwork Digital Limited | Wholesale & retail | 2002 |
| Teber 73 Investment Limited | Real estate | 2023 |
| Tecbuild Limited | Construction | 2025 |
| Tech Axivion Ltd | Wholesale & retail | 2025 |
| Tech Builders Ltd | Construction | 2024 |
| Tech Channel Ambassadors CIC | Education | 2023 |
| Tech Pick Limited | Wholesale & retail | 2026 |
| Tech Solutions BR Limited | Wholesale & retail | 2025 |
| Tech Studio Limited | Information & communication | 2012 |
| Tech Warriors Limited | Extraterritorial | 2017 |
| TECH3 Unlimited | Professional & scientific | 2018 |
| Techcal Ltd | Professional & scientific | 2006 |
| Techcle Technology Ltd | Information & communication | 2013 |
| Techcore Digital Ltd | Information & communication | 2025 |
| Techcore Solutions Limited | Information & communication | 2025 |
| Techedge Ltd | Wholesale & retail | 2012 |
| Techhood Digital Ltd | Wholesale & retail | 2023 |
| Techjot Consultancy Ltd | Information & communication | 2016 |
| Techminds Software Solutions Ltd | Information & communication | 2025 |
| Techneds Investments LLP | | 2018 |
| Techneds Limited | Information & communication | 2016 |
| Technetcom Ltd | Information & communication | 2017 |
| Technical and Special Services LLP | | 2025 |
| Technical Assurance Group Ltd | Information & communication | 2026 |
| Technical Football Centre Limited | Arts & recreation | 2019 |
| Technical Lift Services Ltd | Manufacturing | 2016 |
| Technoefx Ltd | Information & communication | 2025 |
| Techsacc Limited | Information & communication | 2018 |
| Techy Sketching Ltd | Information & communication | 2025 |
| Teddington Research Network Limited | Information & communication | 2007 |
| TEE Creative Ltd | Professional & scientific | 2021 |
| TEE JAY Ltd | Administrative & support | 2022 |
| TEE Line Homes Ltd | Construction | 2025 |
| Teeoree Ltd | Information & communication | 2025 |
| Teeth for Life Limited | Health & social care | 2004 |
| Tefera Ltd | Information & communication | 2022 |
| Tegniese Limited | Information & communication | 2012 |
| Tekdocs Limited | Professional & scientific | 2024 |
| Teklasoft Ltd | Administrative & support | 2025 |
| Tekne Holdings Limited | Professional & scientific | 2008 |
| Tekne Management Limited | Professional & scientific | 1988 |
| Tekne Shopfitting Limited | Construction | 1994 |
| Tektii Ltd | Information & communication | 2025 |
| Telcocentric Limited | Information & communication | 2005 |
| Telecoms Property Consultancy Limited | Information & communication | 2004 |
| Teleflow Limited | Information & communication | 2014 |
| Telegraph Communications Limited | Professional & scientific | 2022 |
| Telisoft Ltd | Information & communication | 2025 |
| Tellet Limited | Wholesale & retail | 2025 |
| Telsonic (U.K.) Limited | Manufacturing | 1978 |
| Temel Consultancy Limited | Professional & scientific | 2014 |
| Temperer Limited | Professional & scientific | 2024 |
| Tempest Cosgrave Limited | Administrative & support | 2006 |
| Tempfill Ltd | Health & social care | 2026 |
| Templar Wines Ltd | Wholesale & retail | 2008 |
| Tems Influence Limited | Wholesale & retail | 2024 |
| Temt Ltd | Professional & scientific | 2012 |
| TEN Bridge Street LLP | | 2008 |
| TEN Sales Coaching Ltd | Professional & scientific | 2015 |
| Tenacity Business Growth Consultancy Ltd | Professional & scientific | 2026 |
| Tenant Alert Ltd | Information & communication | 2026 |
| Tenant Care Consulting Ltd | Real estate | 2025 |
| Tenax JGC Ltd | Other services | 2022 |
| Tenmicron Limited | Professional & scientific | 2024 |
| Teramining Limited | Information & communication | 2017 |
| Terard Limited | Construction | 1975 |
| Terastar UK Ltd | Wholesale & retail | 2025 |
| Terra Enterprises Ltd | Manufacturing | 2020 |
| Terra Viva Properties Limited | Real estate | 2024 |
| Terra-Clad Industrial Roofing Ltd | Construction | 2023 |
| Terracirca C.I.C. | Education | 2025 |
| Tescan Limited | Other services | 1982 |
| Tesoro Pro Tiling Wimborne Ltd | Construction | 2019 |
| Testinspect Limited | Construction | 2004 |
| Testlink Services Limited | Other services | 1991 |
| Testquorum Ltd | Information & communication | 2026 |
| Texxo Limited | Wholesale & retail | 2022 |
| Teyeos Ltd | Information & communication | 2026 |
| TF Capital Allowances Limited | Professional & scientific | 2013 |
| TFA Accountants Limited | Professional & scientific | 2016 |
| TFA Holdings Limited | Financial services | 2022 |
| TFP Online Limited | Education | 2002 |
| TFR Investments Ltd | Real estate | 2020 |
| TFT Academy Ltd | Education | 2019 |
| TG Building and Decorating Ltd | Construction | 2021 |
| TG Media Holdings Ltd | Financial services | 2024 |
| TG Media Ltd | Information & communication | 2024 |
| Tgif Ltd | Administrative & support | 2026 |
| TGM Carpentry Ltd | Construction | 2021 |
| Thai Courtyard Café & Spa Ltd | Hospitality | 2026 |
| Thai Gold (GB) Limited | Wholesale & retail | 2021 |
| Thailula Limited | Health & social care | 2017 |
| Thale Mclernon Ltd | Professional & scientific | 2023 |
| Thamms Limited | Hospitality | 2019 |