| Top Nail Castleford Limited | Other services | 2024 |
| Top Nails Strood Limited | Other services | 2025 |
| Top Plan Limited | Other services | 2016 |
| Top Pro Construction Ltd | Construction | 2022 |
| Top Shop London Limited | Wholesale & retail | 2026 |
| Top Spa Limited | Other services | 2019 |
| Top Sparks Electrical Services Ltd | Construction | 2011 |
| Top TIP Consultants Ltd | Professional & scientific | 2024 |
| Top Tuition Limited | Education | 2025 |
| Top Wash Huntingdon Ltd | Other services | 2026 |
| Top-Surgi-Medica Ltd | Health & social care | 2022 |
| Topaz Club UK Ltd | Other services | 2017 |
| Topcraft Construction Limited | Construction | 1999 |
| Topdown Trading Limited | Wholesale & retail | 2007 |
| Topgiz Properties Ltd | Real estate | 2023 |
| Toprak Decorations Ltd | Other services | 2012 |
| Topstitch Ltd | Manufacturing | 2018 |
| TOR Group International Ltd | Manufacturing | 2019 |
| Torini Ltd | Other services | 2022 |
| Torion Ltd | Wholesale & retail | 2025 |
| Toros Holding Limited | Construction | 2013 |
| Torrid Global Ltd | Professional & scientific | 2015 |
| Torsvag International Limited | Transport & logistics | 2023 |
| TOS Property Ltd | Real estate | 2023 |
| Toska Brickwork Ltd | Construction | 2019 |
| Total Body Reset Limited | Health & social care | 2024 |
| Total Data & Cabling Solutions Ltd | Information & communication | 2026 |
| Total Gym Fitouts Ltd | Manufacturing | 2026 |
| Total Health Care Services Ltd | Administrative & support | 2019 |
| Total Klean Limited | Administrative & support | 2021 |
| Total Removals Limited | Transport & logistics | 2000 |
| Total Sports Investments LLP | | 2016 |
| Total Traffic Management Ltd | Transport & logistics | 2020 |
| Total Wrap Limited | Administrative & support | 2006 |
| Totally Gardens Limited | Administrative & support | 2009 |
| Totally Just ME Productions Ltd | Manufacturing | 2008 |
| Touba Services Ltd | Other services | 2017 |
| Touch of Luxury Ltd | Wholesale & retail | 2026 |
| Tourism Iceland Ltd | Administrative & support | 2023 |
| Tovah Group Ltd | Manufacturing | 2025 |
| TOW ME Away Ltd | Transport & logistics | 2025 |
| Towdah Consulting Ltd | Information & communication | 2017 |
| Tower Garments (London) Limited | Manufacturing | 2012 |
| Towerbridge Construction London Limited | Construction | 2025 |
| Town Carpets of Enfield Ltd | Construction | 2020 |
| Town Food & Wine Ltd | Wholesale & retail | 2018 |
| Town Grill Harpenden Ltd | Hospitality | 2025 |
| Town Tires Ltd | Wholesale & retail | 2022 |
| Toxlaire Limited | Administrative & support | 2007 |
| TP & Munch Ltd | Extraterritorial | 2011 |
| TP Detailing Ltd | Professional & scientific | 2025 |
| TPL London Construction Ltd | Construction | 2021 |
| Tplr Ltd | Real estate | 2023 |
| TPS Suppliers Limited | Wholesale & retail | 2026 |
| Tpshipflow Ltd | Wholesale & retail | 2026 |
| TR Gilbert & Sons Limited | Wholesale & retail | 2025 |
| Tracey Cain Limited | Extraterritorial | 2009 |
| Trade Developer Ltd | Real estate | 2025 |
| Tradesmind AI Ltd | Information & communication | 2026 |
| Tradestone Capital Limited | Professional & scientific | 2025 |
| Tradita Restorant Ltd | Hospitality | 2025 |
| Tradita Shqiptare Ltd | Hospitality | 2017 |
| Training Journeys Ltd | Education | 2025 |
| Transition and Laterlife Matter Ltd | Administrative & support | 2014 |
| Transition Care Services Ltd | Health & social care | 2021 |
| Transition to Tech Ltd | Information & communication | 2025 |
| Transport-Mallrash Ltd | Transport & logistics | 2020 |
| Travel and Tips Ltd | Other services | 2023 |
| Travelfrolics Limited | Administrative & support | 2021 |
| Trend Blinds Ltd | Wholesale & retail | 2021 |
| Trend Organic Ltd | Wholesale & retail | 2021 |
| Trendy Belenus Ltd | Wholesale & retail | 2021 |
| Trentpeak Limited | Real estate | 1976 |
| TRG Pilates Ltd | Arts & recreation | 2025 |
| TRI Loka Media Network Ltd | Wholesale & retail | 2024 |
| Tribe '97 Ltd | Households | 2021 |
| TRIBE22 Ltd | Health & social care | 2024 |
| Triesso Property Management Ltd | Real estate | 2022 |
| Trigo XO Limited | Wholesale & retail | 2025 |
| Trilith Ltd | Information & communication | 2018 |
| Trimmed OUT Ltd | Manufacturing | 2020 |
| Trinh Hoang Limited | Other services | 2016 |
| Trinity (Where Your Life Matters) Ltd | Health & social care | 2021 |
| Trinity Healthcare Plus Limited | Health & social care | 2015 |
| Trinity Media Group Limited | Information & communication | 2022 |
| Trinity Zioness Ltd | Health & social care | 2025 |
| Trios Technologies Ltd | Information & communication | 2016 |
| Triple a Accountancy Limited | Professional & scientific | 2019 |
| Triple a EPC Limited | Financial services | 2024 |
| Triple Infinity Creations Ltd | Information & communication | 2024 |
| Trisha Medical Services Limited | Health & social care | 2015 |
| Tritek Academy Ltd | Information & communication | 2025 |
| Tritek Consulting Limited | Other services | 2017 |
| Triumph Childcare Services Ltd | Health & social care | 2024 |
| TRK Gym Supplies Limited | Wholesale & retail | 2025 |
| Trojan AV Ltd | Construction | 2018 |
| Trojan Highways Ltd | Transport & logistics | 2026 |
| Trong Dung Limited | Other services | 2022 |
| Tropical Fusion Ltd | Hospitality | 2025 |
| Tropical Village Ltd | Wholesale & retail | 2019 |