| Tank Storage Consortium Limited | Other services | 2025 |
| Tape UP Ltd | Manufacturing | 2024 |
| Tarrants Tours Limited | Administrative & support | 2024 |
| Tasker Wallace Associates Limited | Financial services | 2020 |
| Taste Buds in the Park Ltd | Hospitality | 2025 |
| Tasty Cakes Limited | Extraterritorial | 2012 |
| Tattie Bojangles Ltd | Arts & recreation | 2025 |
| Tattoo Incorporated Limited | Arts & recreation | 2019 |
| Tattooed Pixels Ltd | Professional & scientific | 2019 |
| Tattoos by ASH Limited | Arts & recreation | 2014 |
| Taylor Made Marine & Carpentry Limited | Construction | 2014 |
| Taylor Technology Consulting Limited | Information & communication | 2023 |
| Taylor Wallace Roofing Ltd | Construction | 2022 |
| Taylored Compliance Ltd | Professional & scientific | 2023 |
| Taylors Decorating Services Ltd | Construction | 2018 |
| Taylors Maintenance & Construction Limited | Construction | 2020 |
| Taylorsoundscapes Ltd | Information & communication | 2024 |
| TAZ Beauty Pboro Ltd | Other services | 2024 |
| TAZ Beauty Services Limited | Other services | 2020 |
| TAZ Carpentry Services Ltd | Administrative & support | 2017 |
| Taz's Beautybar Limited | Other services | 2021 |
| TB PT Ltd | Other services | 2014 |
| TB Sport Psychology Limited | Administrative & support | 2025 |
| Tbav Services Limited | Other services | 2021 |
| TBC Build Ltd | Construction | 2023 |
| TBC Total Body Conditioning Ltd | Arts & recreation | 2018 |
| Tbcw Property Ltd | Real estate | 2024 |
| TBM Accounting Ltd | Professional & scientific | 2014 |
| TC Accountability Ltd | Other services | 2025 |
| TCE Media Limited | Information & communication | 2024 |
| TD & Co Trading Limited | Wholesale & retail | 2024 |
| TD Plumbing & Heating Ltd | Construction | 2011 |
| TDF Leasing Ltd | Financial services | 2011 |
| TDP Civil Engineering Ltd | Construction | 2026 |
| TDP Properties Ltd | Real estate | 2026 |
| Teaching MR Allen Limited | Education | 2025 |
| Teal Innovation Limited | Construction | 2017 |
| Teal Plumbing and Heating Ltd | Construction | 2022 |
| Tealwood Company Limited | Manufacturing | 1967 |
| Team Payday Ltd | Extraterritorial | 2023 |
| Team Sport Leadership Limited | Administrative & support | 2024 |
| Teameffect Limited | Professional & scientific | 2006 |
| Teamtitans Essex Limited | Education | 2026 |
| Teamtitans Ltd | Education | 2022 |
| Teamwinter Accountancy Ltd. | Professional & scientific | 2015 |
| TEC Connect Limited | Information & communication | 2014 |
| TEC GET Connected Ltd. | Information & communication | 2002 |
| TEC Group Ventures Ltd | Financial services | 2025 |
| TEC Just Better Ltd | Information & communication | 2025 |
| Teccladd Ltd | Construction | 2017 |
| Tech Master Ltd | Real estate | 2015 |
| Tech Master Property Ltd | Real estate | 2019 |
| Tech Reload UK Limited | Other services | 2018 |
| Technical Rescue Limited | Information & communication | 2001 |
| Technical Support & Resources Ltd | Information & communication | 2011 |
| TECHNICALL4IT Limited | Information & communication | 2019 |
| Technoforce Limited | Administrative & support | 2018 |
| Technology at Work Limited | Professional & scientific | 2001 |
| Technology Focus Group Ltd | Administrative & support | 2017 |
| Techshift Digital Ltd | Information & communication | 2023 |
| Tecnico Elevators Limited | Professional & scientific | 2023 |
| Tectonica Limited | Construction | 2011 |
| Teddington Furniture Ltd | Wholesale & retail | 2025 |
| Teddy T Ltd | Wholesale & retail | 2022 |
| Tees Lashes Ltd | Wholesale & retail | 2023 |
| Teknoled-G Limited | Professional & scientific | 2025 |
| Tekta UK Limited | Manufacturing | 2014 |
| Telescope Ltd | Information & communication | 2021 |
| Telic Plant OP Services Limited | Construction | 2018 |
| Tellegen Limited | Professional & scientific | 2022 |
| Telling Media Ltd | Information & communication | 2022 |
| Telo Group Limited | Information & communication | 2025 |
| Tenacity Residentials Ltd | Real estate | 2024 |
| Tender CUT Butchers Limited | Wholesale & retail | 2007 |
| Tender Engine Ltd | Professional & scientific | 2025 |
| Teracode Limited | Information & communication | 2006 |
| Teromal Ltd | Health & social care | 2026 |
| Terra Core Mining Ltd | Mining & quarrying | 2024 |
| Tessann Limited | Real estate | 1989 |
| Testforless Limited | Education | 2023 |
| Tete Pawa Executive Coaching Limited | Administrative & support | 2020 |
| Tete Pawa Therapy Limited | Health & social care | 2020 |
| Tete Pawã Advertising Limited | Professional & scientific | 2020 |
| TF Pipeworxe Limited | Construction | 2006 |
| Tfxr Property Limited | Professional & scientific | 2025 |
| TG Gallaway Limited | Information & communication | 2011 |
| TGR Homes Ltd | Real estate | 2020 |
| TGS Electrical Services Limited | Construction | 2018 |
| That's Neat Signs Limited | Other services | 2016 |
| Thatcher Holdings (UK) Ltd | Financial services | 2021 |
| Thatcher's Copse Management Company Ltd | Households | 2025 |
| Thatchers Motor Company Ltd | Wholesale & retail | 2016 |
| Thds Property Ltd | Real estate | 2024 |
| THE Achievers Hub Ltd | Education | 2026 |
| THE Animal Days Ltd. | Other services | 2023 |
| THE Artisan General Store Limited | Wholesale & retail | 2018 |
| THE Asembl Group Limited | Financial services | 2019 |
| THE Association of Early Pregnancy Units | Health & social care | 2001 |
| THE Auction House Petersfield Limited | Hospitality | 2022 |
| THE Balogun Bassey Community Interest Company | Education | 2024 |