| Todosi Plumbing Limited | Construction | 2016 |
| Together Dental Limited | Health & social care | 2019 |
| Togo Intertrans Ltd | Wholesale & retail | 2020 |
| Togridge LP | | 2017 |
| Tokei Properties Investments Limited | Real estate | 2022 |
| Tokei Transport Ltd | Transport & logistics | 2025 |
| Tokyo Dyes Ltd | Wholesale & retail | 2018 |
| Toland Construction Limited | Construction | 2018 |
| Told by Magic Ltd | Professional & scientific | 2025 |
| Tolhen Developments Limited | Construction | 2022 |
| Tolly and Sons Limited | Wholesale & retail | 2003 |
| Tolly Electrical Ltd | Construction | 2019 |
| Tolly Investments Limited | Real estate | 1995 |
| TOM Croxon Management Limited | Administrative & support | 1999 |
| TOM the Gardener Limited | Administrative & support | 2015 |
| Tomi Consultants Ltd | Manufacturing | 2015 |
| Tomico Properties Limited | Real estate | 2016 |
| Tompkins Bros Ltd | Construction | 2021 |
| Toms Family Investments Limited | Construction | 2024 |
| Tonecom Ltd | Wholesale & retail | 2022 |
| Toni's Greek Tavern Limited | Hospitality | 2024 |
| Tonic and Root Ltd | Manufacturing | 2026 |
| Tonino Ice Cream Ltd | Wholesale & retail | 2021 |
| Tonitrum Consulting Ltd | Professional & scientific | 2021 |
| Toni’S Greek Coffee Bar Ltd | Hospitality | 2023 |
| Tonni Construction Limited | Construction | 2022 |
| Tono&Petka Limited | Professional & scientific | 2013 |
| TOO Much Travel Ltd | Administrative & support | 2025 |
| Toolsflux Limited | Manufacturing | 2025 |
| Toop Solutions Limited | Information & communication | 2024 |
| Top 10 Solutions Limited | Administrative & support | 2004 |
| Top Caps Headwear Limited | Wholesale & retail | 2005 |
| Top Class Plastering Ltd | Construction | 2017 |
| Top Driving Academy Ltd | Other services | 2017 |
| Top Fields Accounting Ltd | Professional & scientific | 2021 |
| Top Law Ltd | Extraterritorial | 2025 |
| Top N Top Ltd | Wholesale & retail | 2020 |
| Top Notch Catering Ltd. | Hospitality | 2018 |
| Top Structural Design Limited | Professional & scientific | 2023 |
| Topaz Associates Limited | Administrative & support | 2011 |
| Topbuild (UK) Ltd. | Construction | 2008 |
| Topcard Limited | Information & communication | 2015 |
| Tops Clothing Limited | Wholesale & retail | 2023 |
| Tops Pizza (Watford) Ltd | Hospitality | 2015 |
| Tops R Cuisine Ltd | Hospitality | 2018 |
| Topscale Ltd | Information & communication | 2012 |
| Topserv Co LP | | 2019 |
| Topvest Limited | Real estate | 1973 |
| Topwrench Ltd | Wholesale & retail | 2024 |
| Tora Bora Limited | Professional & scientific | 2025 |
| Tornado 360 Ltd | Professional & scientific | 2021 |
| Tosha Stays Ltd | Hospitality | 2026 |
| Total Back Office Solutions Limited | Administrative & support | 1995 |
| Total Clearances Ltd | Transport & logistics | 2023 |
| Total Consultants Limited | Information & communication | 1992 |
| Total Craft Ltd | Construction | 2025 |
| Total Electrical Solutions London Limited | Professional & scientific | 2016 |
| Total Employment Agency Limited | Administrative & support | 2014 |
| Total Goldmine Productions Limited | Information & communication | 2014 |
| Total Homes (Bromley) Ltd | Construction | 2021 |
| Total Look Tiles Limited | Wholesale & retail | 2016 |
| Total Perimeter Protection Ltd | Administrative & support | 2021 |
| Total Security Protection Limited | Administrative & support | 1988 |
| Totalace Limited | Administrative & support | 1997 |
| Totalhealth Connect Ltd | Professional & scientific | 2025 |
| Tothalectric Ltd | Construction | 2024 |
| Tottenham Enterprise Centre Limited | Other services | 1986 |
| Toucan World Limited | Information & communication | 2022 |
| Touch Metals Ltd. | Manufacturing | 2012 |
| Toumi Transit Ltd | Transport & logistics | 2021 |
| Tower GAS Ltd | Construction | 2016 |
| Tower Systems Limited | Manufacturing | 1994 |
| Towereach 2 Limited | Construction | 2018 |
| Towereach Limited | Construction | 1988 |
| Towerstock Properties (Ealing) Limited | Real estate | 2006 |
| Town & Country Land Management Limited | Agriculture & fishing | 2004 |
| Town & Country Taverns Ltd | Professional & scientific | 2019 |
| Town Centre Apartments Ltd | Real estate | 2013 |
| Townson City Consultants Limited | Real estate | 2015 |
| Toxeuma Ltd | Hospitality | 2024 |
| Toy Creative Ltd | Professional & scientific | 2021 |
| TP Windows Ltd | Construction | 2025 |
| TPA Capital Investments Limited Partnership | | 2019 |
| TPA Capital LLP | | 2018 |
| TPA Estates Ltd | Real estate | 2019 |
| Tpcn UK Limited | Wholesale & retail | 2016 |
| TPG Projects Limited | Construction | 2017 |
| Tphr Rail Ltd | Construction | 2022 |
| TPS Commercials Limited | Wholesale & retail | 2025 |
| TPS Direct Limited | Wholesale & retail | 2020 |
| Traaseth Properties Limited | Real estate | 2023 |
| Track & Air Design Ltd | Professional & scientific | 2011 |
| Tracks Group Limited | Financial services | 2017 |
| Trade and Services Ltd | Wholesale & retail | 2020 |
| Trade X PVT Ltd | Wholesale & retail | 2025 |
| Trading First Group Limited | Other services | 2015 |
| Trafalgar Healthcare Limited | Health & social care | 1997 |
| Traffic Tech Services Ltd | Manufacturing | 2020 |
| TRAILERS2SET Ltd | Administrative & support | 2018 |
| Trailgift Limited | Wholesale & retail | 2026 |