| THE IAR Group Ltd | Manufacturing | 2016 |
| THE Inclusion Culture Ltd | Professional & scientific | 2021 |
| THE Italian Connection (London) Limited | Administrative & support | 1996 |
| THE Kloak Room Limited | Wholesale & retail | 2020 |
| THE Landscaping Contractors Ltd | Construction | 2015 |
| THE Life Style Reset Limited | Health & social care | 2026 |
| THE Lining Company Limited | Extraterritorial | 2006 |
| THE Little Box Company Limited | Real estate | 2013 |
| THE Local Handyman London Ltd | Construction | 2021 |
| THE Lozinski Consultancy Limited | Professional & scientific | 2014 |
| THE Maki Clinic Ltd | Professional & scientific | 2021 |
| THE MC Busiiness Limited | Real estate | 2022 |
| THE Motor House Somerset Ltd | Wholesale & retail | 2026 |
| THE Movie Shop Ltd | Wholesale & retail | 2004 |
| THE New Grange Care Home Limited | Health & social care | 2008 |
| THE Packhorse Case Company Limited | Manufacturing | 2014 |
| THE Poetic Counsellor Limited | Health & social care | 2026 |
| THE Rack Room Ltd | Information & communication | 2023 |
| THE Radlett Management Company Ltd | Households | 2019 |
| THE Short Stay by Spenta Ltd | Real estate | 2026 |
| THE Smart Probate Ltd | Other services | 2024 |
| THE Supply Square Ltd | Wholesale & retail | 2022 |
| THE Syrian Sunflower Ltd | Hospitality | 2024 |
| THE Technologies Group Limited | Information & communication | 1989 |
| THE Tree Construction Ltd | Construction | 2024 |
| THE UK Jordanian Community Ltd | Hospitality | 2026 |
| THE Unicorn Baking Co Ltd | Hospitality | 2020 |
| THE Union of Orthodox Hebrew Congregations | Education | 2012 |
| THE Velvet Ribbon Ltd | Manufacturing | 2019 |
| THE Village Buzz (Chorleywood) Ltd | Wholesale & retail | 2014 |
| THE Welshore Community Hub | Education | 2010 |
| THE World in HER Words Ltd | Information & communication | 2020 |
| THE Wyld Herb Company Ltd | Manufacturing | 2022 |
| THE Youth Development Academy Ltd | Education | 2018 |
| Thee Lifestyle Edit Ltd | Hospitality | 2025 |
| Theena Salon Ltd | Other services | 2023 |
| Theo Gifts Ltd | Wholesale & retail | 2025 |
| There IS a Solution Ltd | Real estate | 2020 |
| Thermabags Limited | Manufacturing | 2024 |
| Thermal FIX Ltd | Manufacturing | 2010 |
| Third Lane Haulage Ltd | Transport & logistics | 2021 |
| Thomas Business Group Limited | Wholesale & retail | 2019 |
| Thomas Transport 4 U Limited | Transport & logistics | 2020 |
| Thorntons Limited | Manufacturing | 1921 |
| Thpp Ltd | Information & communication | 2025 |
| Thriived Ltd | Information & communication | 2021 |
| Thyestes Ltd | Financial services | 2014 |
| Thyme Culinary Designs Ltd | Hospitality | 2013 |
| Tiago Pereira VFX Ltd | Information & communication | 2026 |
| Tian Foods Limited | Wholesale & retail | 2024 |
| Tibi T Ltd | Construction | 2024 |
| Tides Electrical Distributors Ltd | Wholesale & retail | 2023 |
| Tikka & Talk Ltd | Hospitality | 2022 |
| Tillergrade Properties Limited | Professional & scientific | 1980 |
| Tinfoil Studios Ltd | Financial services | 2023 |
| Titan Coatings Limited | Wholesale & retail | 2022 |
| Titov Veles Limited | Administrative & support | 2016 |
| Titus Lodge Ltd | Real estate | 2023 |
| Tivox Ltd | Construction | 2019 |
| Tiwana GR Limited | Administrative & support | 2012 |
| Tj’S Dog House Ltd | Other services | 2025 |
| TK Maths Academy Ltd | Education | 2020 |
| TKPC2 Limited | Hospitality | 2009 |
| TM Health Ltd | Health & social care | 2022 |
| TM Medical Ltd | Financial services | 2025 |
| TM Rahma Holdings Limited | Financial services | 2024 |
| Tmarie Limited | Information & communication | 2021 |
| TMG Consultancy Service Limited | Professional & scientific | 2017 |
| Tmhcp Ltd | Professional & scientific | 2022 |
| TMN Enterprise Limited | Wholesale & retail | 2017 |
| TMT Legacy Limited | Transport & logistics | 2023 |
| TNV Global Limited | Information & communication | 2024 |
| Todd Truck Repairs Limited | Manufacturing | 2017 |
| Todmorden Foods Ltd | Hospitality | 2021 |
| Tollington Builders Ltd | Construction | 2017 |
| TOM Morris Productions Ltd | Arts & recreation | 2012 |
| Tomkin Construction & Building Limited | Construction | 2022 |
| Tommy T**Ker Ltd | Wholesale & retail | 2008 |
| Tomorrow's Warriors Limited | Administrative & support | 1998 |
| Tony & Sisters Ltd | Wholesale & retail | 2017 |
| Toonistry Ltd | Arts & recreation | 2017 |
| Top Choice Building Services Ltd | Construction | 2026 |
| Top Choice Roof Care Ltd | Construction | 2025 |
| Top Financial Solutions Ltd | Other services | 2018 |
| Top Maintenance Ltd | Construction | 2018 |
| Topcare Health Ltd | Health & social care | 2022 |
| Total Property Support Ltd | Transport & logistics | 2026 |
| Touchcast Studios UK Limited | Information & communication | 2014 |
| Tour Tech Hospitality Ltd | Information & communication | 2024 |
| Town Builder Ltd | Manufacturing | 2025 |
| Trade Ecommerce Limited | Wholesale & retail | 2023 |
| Trade Mahal Ltd | Wholesale & retail | 2022 |
| Tradeflow Consulting Ltd | Professional & scientific | 2024 |
| Tradfri Limited | Wholesale & retail | 2022 |
| Trading Builder UK Ltd | Wholesale & retail | 2025 |
| Trading Connect Ltd | Manufacturing | 2022 |
| Traditional Style Properties Limited | Real estate | 2022 |
| TRAIN360 Ltd | Arts & recreation | 2026 |
| Tranquil Healthcare (Osteopathy) Limited | Health & social care | 2013 |
| Tranquil Recovery Care Ltd | Health & social care | 2025 |