| TLM Bars Ltd | Hospitality | 2024 |
| TLM Property Developments Ltd | Construction | 2024 |
| TM Caring Nature Limited | Health & social care | 2023 |
| TM UK Car Care Ltd | Professional & scientific | 2019 |
| TM UK Car Wash Limited | Administrative & support | 2022 |
| TM UK Cars Ltd | Wholesale & retail | 2016 |
| TM UK Motors Ltd | Wholesale & retail | 2026 |
| TM UK Property Investment Ltd | Real estate | 2025 |
| TM UK Trading Ltd | Wholesale & retail | 2016 |
| TM UK Travels Ltd | Administrative & support | 2026 |
| TMR Flooring Limited | Construction | 2003 |
| Tmrt Property UK Ltd | Real estate | 2024 |
| Tn-C Electrical & Jointing Ltd | Construction | 2026 |
| TNF Estates Limited | Real estate | 2020 |
| Toca Construction Ltd | Construction | 2023 |
| Tocilla Ltd | Households | 2025 |
| Todc Group Limited | Other services | 2026 |
| Todorov Cablind Ltd | Construction | 2014 |
| Together Homes Group Limited | Real estate | 2021 |
| TOM Murphy Coaching Limited | Arts & recreation | 2026 |
| Tomexpertsmoves Limited | Water & waste | 2025 |
| Tommy Luck Consulting Ltd | Professional & scientific | 2023 |
| Tommys Bodyshop Limited | Wholesale & retail | 2024 |
| Tona & Co. Ltd | Construction | 2014 |
| Tonys Bar Limited | Hospitality | 2003 |
| Toolup Analytics Ltd | Information & communication | 2024 |
| Toot Properties Limited | Real estate | 2020 |
| Toothpal Limited | Information & communication | 2025 |
| Top Discount Electrical Stores Limited | Wholesale & retail | 1981 |
| Top MD Electrical Services Ltd | Construction | 2026 |
| Top Padel Ltd | Wholesale & retail | 2023 |
| Top Raised Access Flooring Limited | Construction | 2025 |
| Topline Accomodations Limited | Hospitality | 2026 |
| Topline FM Limited | Construction | 2023 |
| Topspec Builders (Essex) Limited | Construction | 2023 |
| Torus Motorsport Ltd | Professional & scientific | 2021 |
| Tostim Ltd | Health & social care | 2014 |
| Tostitosti Ltd | Manufacturing | 2024 |
| Total Home Revive Ltd | Construction | 2021 |
| Total Inhouse Services Limited | Professional & scientific | 2014 |
| Total Property Maintenance Services Limited | Administrative & support | 2009 |
| Totus Digital Limited | Public administration | 2020 |
| Toucan Talent Agency Ltd | Arts & recreation | 2020 |
| Touch Hair Salon Limited | Other services | 2017 |
| Touche Faces Ltd | Health & social care | 2015 |
| TOW N Go Limited | Transport & logistics | 2017 |
| Tower Connect Limited | Administrative & support | 2011 |
| Tower Connect Property Services Limited | Real estate | 2026 |
| Towis Limited | Real estate | 2021 |
| Townshend Associates Limited | Construction | 2019 |
| Toyenyen Clothing Limited | Wholesale & retail | 2022 |
| TP Recruitment Limited | Administrative & support | 2024 |
| TPL Transport Ltd | Transport & logistics | 2025 |
| TPM Gardening Ltd | Administrative & support | 2022 |
| TPM Sparkling Clean Ltd | Administrative & support | 2024 |
| TPM Window Cleaning Ltd | Administrative & support | 2021 |
| TR1 Holdings Ltd | Financial services | 2023 |
| Tracee Limited | Real estate | 2020 |
| Trade Merchants Limited | Information & communication | 2016 |
| Tradecrafters Ltd | Wholesale & retail | 2024 |
| Tradeline Solutions Limited | Administrative & support | 2010 |
| Trafalgar Residential Limited | Real estate | 2023 |
| Trahass Ltd | Professional & scientific | 2021 |
| Tralee Ltd | Health & social care | 2019 |
| Trandafir Construction Ltd | Construction | 2019 |
| Tranquil Retreats Limited | Health & social care | 2024 |
| Trans Euro Freight Limited | Transport & logistics | 2024 |
| Trans Euro Group Limited | Professional & scientific | 2022 |
| Transitional Consulting Services Limited | Information & communication | 2010 |
| Transmarine Shipping Agencies Limited | Extraterritorial | 1957 |
| Transpotech UK Limited | Transport & logistics | 2025 |
| Transway Rail Services Ltd | Construction | 2018 |
| Transwede Limited | Transport & logistics | 2007 |
| Travel Claims and Mediation Ltd | Professional & scientific | 2020 |
| Travel Guard Ltd | Administrative & support | 2025 |
| Travel Injections Ltd | Health & social care | 2017 |
| Travelling Facility London Ltd | Transport & logistics | 2024 |
| Treal Care UK Limited | Administrative & support | 2018 |
| Treal Property and Investments Limited | Real estate | 2021 |
| Treatment Finance Limited | Administrative & support | 2017 |
| Treatment Plan Limited | Administrative & support | 2022 |
| Treetops Dental Practice Limited | Health & social care | 2008 |
| Tremolo HR Limited | Administrative & support | 2026 |
| Trenchev Construction Ltd | Construction | 2024 |
| Trendy Cafe Ltd | Hospitality | 2023 |
| TRI Medical Limited | Health & social care | 2015 |
| Tricon Trading Ltd | Professional & scientific | 2020 |
| Trilateral Pictures Limited | Information & communication | 2021 |
| Trimming Shop Group Limited | Wholesale & retail | 2015 |
| Trimoore Ltd | Hospitality | 2023 |
| Trina and Spencer Ltd | Health & social care | 2014 |
| Trinity Capex Ltd | Real estate | 2021 |
| Trinity Commercial Finance Ltd | Financial services | 2023 |
| Trinity Investments Limited | Real estate | 2008 |
| Trinity Mortgages Ltd | Financial services | 2017 |
| Trio Cafe Ltd | Manufacturing | 2025 |
| Trio Group Limited | Construction | 2017 |
| Trio Homes (UK) Limited | Construction | 2010 |
| Trio Marble Ltd | Construction | 2014 |
| Triovend Ltd | Wholesale & retail | 2026 |