| T.J.Heating Limited | Households | 2015 |
| Taashi Investment Limited | Real estate | 2020 |
| TAB Mechanical Services Ltd | Construction | 2023 |
| Tabassum Supermarket Ltd | Wholesale & retail | 2024 |
| Tachyon IT Solutions Limited | Information & communication | 2017 |
| Tachyon Properties Limited | Real estate | 2022 |
| Taha Motors Ltd | Wholesale & retail | 2017 |
| TAJ Buttar Transport Ltd | Transport & logistics | 2024 |
| Takeover Promotions Ltd | Administrative & support | 2025 |
| Tale BE Told Theatre C.I.C. | Arts & recreation | 2016 |
| Talha PAN Shop UK Ltd | Hospitality | 2026 |
| Talia Transport Ltd | Wholesale & retail | 2025 |
| Talking Champs Ltd | Education | 2026 |
| Talon Estates LLP | | 2021 |
| Talon Holdings Ltd | Real estate | 2026 |
| Tamas Aurel 1171 Limited | Transport & logistics | 2015 |
| Tandberg Products UK Limited | Manufacturing | 2002 |
| Tandberg Telecom UK Limited | Information & communication | 1997 |
| Tangible Knowledge Limited | Wholesale & retail | 2020 |
| Tangra Building & Constructions Services Ltd | Construction | 2022 |
| Tanit Properties Ltd | Real estate | 2021 |
| Tanmart Limited | Wholesale & retail | 2025 |
| Tannieh's Care Limited | Health & social care | 2022 |
| Tanpopo Holdings Limited | Financial services | 2022 |
| Tanpopo Japanese Food EOT Limited | Administrative & support | 2023 |
| Tanpopo Japanese Food Limited | Manufacturing | 2008 |
| Tanvi Builders Limited | Construction | 2017 |
| Tara Solutions Ltd | Information & communication | 2012 |
| Targeting Right Marketing Ltd | Information & communication | 2015 |
| Tarrant Design Limited | Information & communication | 2015 |
| Taruna Kapoor Properties Limited | Real estate | 2025 |
| Taskov Properties Ltd | Real estate | 2026 |
| Tasteful Opportunities Limited | Hospitality | 2021 |
| Tasty Tunes Ltd | Wholesale & retail | 2026 |
| Tatenda. C. Limited | Health & social care | 2022 |
| Tatev Consulting Limited | Administrative & support | 2019 |
| Tattvamasi Limited | Information & communication | 2025 |
| Tausug-British (Taubrit) Community in UK CIC | Education | 2023 |
| TBS Travel Ltd | Transport & logistics | 2020 |
| TC Logistic Solutions Limited | Transport & logistics | 2010 |
| TCA Consultancy Limited | Professional & scientific | 2021 |
| TDF Records Limited | Arts & recreation | 2007 |
| TDP Transport Limited | Transport & logistics | 2011 |
| TDR Services Ltd | Manufacturing | 2022 |
| TE Vipra Co Limited | Information & communication | 2019 |
| Tech Consulting Partners Ltd | Information & communication | 2014 |
| Tech Geek Feltham Limited | Wholesale & retail | 2017 |
| Tech HOME77 Ltd | Real estate | 2026 |
| Tech Pixels Ltd | Information & communication | 2021 |
| Techno Tronics Limited | Wholesale & retail | 2016 |
| Technology & HR Consultancy Limited | Information & communication | 2005 |
| Techplix Ltd | Information & communication | 2016 |
| TECHSOLUTIONS4U Ltd | Information & communication | 2024 |
| Techtoll Software Associates Ltd | Information & communication | 2013 |
| Techtrack Limited | Transport & logistics | 2013 |
| Tekfusion Ltd | Information & communication | 2025 |
| Telios Digital Ltd | Information & communication | 2018 |
| TEN Holdings Limited | Financial services | 2026 |
| Tevbest Ltd | Health & social care | 2023 |
| Thakali Ltd | Hospitality | 2025 |
| Thakur & Co Accountants Limited | Professional & scientific | 2026 |
| Thames Contractors Ltd | Construction | 2014 |
| Thames Timber & Builders Merchant Ltd | Wholesale & retail | 2015 |
| Thames Title Ltd | Real estate | 2016 |
| Thapa & Co London Ltd | Real estate | 2024 |
| Thara Health Ltd | Health & social care | 2015 |
| THE Athletic Gear Services Ltd | Wholesale & retail | 2020 |
| THE Bespoke Painting Company Ltd | Construction | 2025 |
| THE Boss Coach Ltd | Health & social care | 2022 |
| THE Bounce Generation Ltd | Administrative & support | 2021 |
| THE Collective Consultants Ltd | Professional & scientific | 2015 |
| THE Crown 777 Limited | Other services | 2018 |
| THE Danso Corporation Ltd. | Financial services | 2023 |
| THE Desi Pantry Ltd | Transport & logistics | 2020 |
| THE Design Gurus Limited | Information & communication | 2005 |
| THE Dough Limited | Wholesale & retail | 2019 |
| THE Dragon Centre Company Limited | Construction | 2001 |
| THE Fourask Limited | Hospitality | 2019 |
| THE Framed Collective Ltd | Information & communication | 2025 |
| THE Grand Consortia Limited | Construction | 2003 |
| THE Halford Bridge Bar Limited | Hospitality | 2021 |
| THE Halford Bridge Inn Limited | Hospitality | 2021 |
| THE Healing Circle C.I.C. | Health & social care | 2025 |
| THE Healing Home Collective CIC | Education | 2025 |
| THE Healing Space Consulting Limited | Professional & scientific | 2025 |
| THE Humble Family Ltd | Hospitality | 2020 |
| THE Institute of Freight Forwarders Limited | Extraterritorial | 1989 |
| THE Kollab Network Ltd | Arts & recreation | 2023 |
| THE Linkx Solutions Ltd | Information & communication | 2024 |
| THE London Comfy Garden Ltd | Construction | 2022 |
| THE Magic Treehouse Day Nursery Ltd | Education | 2021 |
| THE MED Guru Ltd | Transport & logistics | 2021 |
| THE Midnight Thyme Ltd | Manufacturing | 2025 |
| THE New TAN Box Ltd | Other services | 2017 |
| THE Nilgiris Ltd | Information & communication | 2026 |
| THE Nthcolumn Limited | Other services | 2015 |
| THE Pangean Ltd | Information & communication | 2022 |
| THE Paniym Network C.I.C. | Administrative & support | 2025 |
| THE Polish Baker Limited | Manufacturing | 2009 |
| THE Positive Movement Project CIC | Arts & recreation | 2020 |