| T.O.B. International Wholesale Limited | Wholesale & retail | 2004 |
| T.P.A.S. Capital Limited | Financial services | 2017 |
| T.R.Stares Roofing | | 1990 |
| T.Rippon & Sons Limited | Extraterritorial | 1972 |
| T.Rippon & Sons(Holdings)Limited | Real estate | 1955 |
| T.T. Matthews (Farms) Limited | Agriculture & fishing | 1961 |
| T.Webb Limited | Professional & scientific | 2019 |
| TA Rigging Ltd | Construction | 2025 |
| Taberer Consulting Limited | Professional & scientific | 2013 |
| Tabico Consulting Ltd | Professional & scientific | 2018 |
| Tablet Rentals Limited | Professional & scientific | 2009 |
| Tabor Nominees Limited | Professional & scientific | 1975 |
| Tabsoft Limited | Information & communication | 2006 |
| Taco Taco Shoreditch Ltd | Hospitality | 2023 |
| Tacotaco Ltd | Hospitality | 2022 |
| Tadeor Limited | Professional & scientific | 2016 |
| TAF Health Care Ltd | Health & social care | 2017 |
| TAG Bespoke Metals Ltd | Manufacturing | 2023 |
| Tagbit Solutions Limited | Information & communication | 2025 |
| Tagtek Ltd | Information & communication | 2010 |
| Taico Properties Ltd | Real estate | 2020 |
| Tail END Ventures Ltd | Wholesale & retail | 2025 |
| Tailored Image UK Limited | Manufacturing | 2005 |
| Taiping Toy Schnauzers Ltd | Wholesale & retail | 2022 |
| Take My Tablets Ltd | Health & social care | 2024 |
| Take the Lead Ltd | Other services | 2024 |
| Talawa Entertainment LLP | | 2026 |
| Talent Magnet Ltd | Administrative & support | 2019 |
| Talentforgegroup Ltd | Professional & scientific | 2023 |
| Talha Consultancy Ltd | Administrative & support | 2025 |
| Talk Health Plus Ltd | Health & social care | 2025 |
| Talk to the Hands Learning Ltd. | Education | 2024 |
| Talltree Property Limited | Professional & scientific | 2005 |
| Tally Homes Limited | Construction | 2006 |
| TAM Warehousing Limited | Real estate | 2020 |
| Tamev 2701 Limited | Hospitality | 2025 |
| Tamsyn Mason Design Ltd | Professional & scientific | 2025 |
| Tamsyn Mason Interior Design Studio Ltd | Professional & scientific | 2023 |
| Tanber HR 46 Ltd | Administrative & support | 2019 |
| Tanber HR 48 Ltd | Administrative & support | 2019 |
| Tanber HR 68 Ltd | Administrative & support | 2019 |
| Tandem Design Limited | Professional & scientific | 2003 |
| Tandoori Spicy Limited | Hospitality | 2025 |
| Tangent Electrical Limited | Construction | 1983 |
| Tangent Electrical Services Ltd | Construction | 2017 |
| Tangi Limited | Hospitality | 2017 |
| Tanglewood Place Management Company Limited | Households | 2021 |
| Tangra Ltd | Construction | 2024 |
| Tankcare Engineering (Sales) Limited | Manufacturing | 2007 |
| Tanker Services Limited | Wholesale & retail | 2015 |
| Tanks & Pipeworks Limited | Manufacturing | 2000 |
| Tann-Line Limited | Wholesale & retail | 2017 |
| Tantrum Films Limited | Information & communication | 1995 |
| Tanvi and AVY Ventures Ltd | Real estate | 2024 |
| Tany Ltd | Construction | 2020 |
| Taoram Limited | Professional & scientific | 2015 |
| TAP Galleries Limited | Wholesale & retail | 2011 |
| Tapstanya Limited | Health & social care | 2011 |
| Tare Plastic Surgery Ltd | Health & social care | 2008 |
| Target Publishing Limited | Information & communication | 2000 |
| Target Tracker Limited | Financial services | 2019 |
| Tarif Developments Limited | Construction | 1987 |
| Taritek Services Ltd | Administrative & support | 2024 |
| Tari’S Pâtisserie Ltd | Manufacturing | 2022 |
| Tarja Limited | Information & communication | 2014 |
| Taroball Studios Ltd | Arts & recreation | 2024 |
| Tarragon Inns Limited | Hospitality | 1998 |
| Tarzcouz Ltd | Wholesale & retail | 2025 |
| Taste Hub Ltd | Wholesale & retail | 2013 |
| Tate Anne Properties Ltd | Real estate | 2024 |
| Tate Construction Services Limited | Construction | 2018 |
| Tattooist Limited | Arts & recreation | 2024 |
| Tavern Bar Ltd | Hospitality | 2024 |
| Tavistock 1878 Capital Ltd | Real estate | 2019 |
| Tawa Associates Ltd | Financial services | 2001 |
| Tawa Management Ltd | Financial services | 2001 |
| Tax Advisor Plus Limited | Professional & scientific | 2025 |
| Tax Drive Ltd | Professional & scientific | 2025 |
| Tax-Pert Accountants Limited | Professional & scientific | 2017 |
| Taxi Ace Ltd | Transport & logistics | 2026 |
| Taylor and Taylor PUB Ltd | Hospitality | 2022 |
| Taylor Financial Management Limited | Financial services | 2021 |
| Taylor Generations Limited | Financial services | 2022 |
| Taylor Haldane Barlex LLP | | 2008 |
| Taylor Haldane Barlex Solicitors Limited | Professional & scientific | 2011 |
| Taylor'D Escapes Limited | Real estate | 2025 |
| Taylor-Langley LLP | | 2005 |
| Taylormade Property Development Limited | Construction | 2008 |
| Taylors Electrical Contractors Ltd | Construction | 2022 |
| Tayo and Doyin Ltd | Wholesale & retail | 2020 |
| Tazdrive Ltd | Transport & logistics | 2019 |
| TB Barber Shop Ltd | Other services | 2025 |
| TBC Aesthetics Ltd | Other services | 2026 |
| TBH Collective Limited | Other services | 2022 |
| TC Coating Ltd | Construction | 2023 |
| TC Commercial Solutions Ltd | Professional & scientific | 2017 |
| TC Personnel Limited | Administrative & support | 2020 |
| Tcdl Management Ltd | Real estate | 2021 |
| Tcdl Solutions Ltd | Wholesale & retail | 2012 |
| Tcdl Steel Ltd | Extraterritorial | 2019 |