| Susash UK Ltd | Health & social care | 2012 |
| Sushi Star Ltd | Hospitality | 2023 |
| Suthan Ltd | Construction | 2024 |
| Sutharshini DRY Clean Ltd | Other services | 2019 |
| Suvai Aruvi Ltd | Hospitality | 2017 |
| SW17 Van Sales Ltd | Wholesale & retail | 2019 |
| SW19 Wardrobes Limited | Construction | 2010 |
| Swald Limited | Professional & scientific | 2025 |
| Swascorp Ltd | Information & communication | 2006 |
| Sweet Light Service Ltd | Administrative & support | 2023 |
| SWI Service Ltd | Hospitality | 2025 |
| Swift Carriers Ltd | Transport & logistics | 2024 |
| Swift UK Education & Careers Solutions Ltd | Education | 2025 |
| Swiftest Work Ltd | Wholesale & retail | 2025 |
| Swiftlyrising Ltd | Wholesale & retail | 2021 |
| Swiftsolve Ltd | Information & communication | 2023 |
| SWL Services Ltd | Real estate | 2021 |
| SWP Scaffolding Limited | Construction | 2015 |
| Swreformerfit Ltd | Arts & recreation | 2023 |
| Sybro Limited | Extraterritorial | 1935 |
| Sync & Speak Ltd | Information & communication | 2025 |
| Synechrome Ltd | Information & communication | 2011 |
| Synergy (London) Heating & Plumbing Ltd | Construction | 2016 |
| Synergy Care Limited | Health & social care | 2019 |
| Synora Staffing Solutions Limited | Administrative & support | 2026 |
| Synthcode Limited | Information & communication | 2026 |
| Synthesis Advisory Services Ltd | Professional & scientific | 2023 |
| Synwin Solutions Ltd | Information & communication | 2014 |
| Syscom-It Limited | Information & communication | 2014 |
| Szafa Electrician Ltd | Construction | 2015 |
| Szl-It Limited | Manufacturing | 2024 |
| T & M PVT Ltd | Wholesale & retail | 2025 |
| T a a Work Limited | Hospitality | 2020 |
| T and B Electricians Ltd | Construction | 2014 |
| T Distribution Ltd | Transport & logistics | 2026 |
| T K Homes (UK) Limited | Real estate | 2014 |
| T K Plant Ltd | Construction | 2014 |
| T&C 9625 Limited | Transport & logistics | 2022 |
| T-Rosy Ltd | Other services | 2024 |
| T-Shack Limited | Hospitality | 2023 |
| T.C.B. CAD Design Limited | Professional & scientific | 2012 |
| T.E Haven Homes Ltd | Real estate | 2026 |
| Tabaq Caterers Limited | Hospitality | 2019 |
| Tabaq Catering Services Ltd | Hospitality | 2025 |
| Tabaq Event Planners Ltd | Other services | 2024 |
| Tabaq Event Planners NO 1 Ltd | Hospitality | 2025 |
| Tadla Limited | Other services | 2024 |
| Taffy's HOW Limited | Households | 2019 |
| TAG Elezz Ltd | Hospitality | 2024 |
| Tagimoucia Ltd | Health & social care | 2026 |
| Taha Enterprises Limited | Transport & logistics | 2010 |
| Taha Logistics Ltd | Transport & logistics | 2025 |
| Taha Removals Ltd | Transport & logistics | 2025 |
| Tahir Khan Enterprises Ltd | Other services | 2018 |
| Taiwo and Kehinde Beauty Salon Ltd | Other services | 2024 |
| Takov Ltd | Construction | 2017 |
| Talk Dygital Limited | Information & communication | 2010 |
| Tamil Language Centre Ltd | Education | 2021 |
| Tamil Students Initiative UK Ltd | Education | 2023 |
| Tammy D'S Auto Care Ltd | Wholesale & retail | 2025 |
| Tangles Hair Salon Ltd | Other services | 2013 |
| Tanveer Ahmed Property Services Limited | Construction | 2014 |
| Tapland Limited | Real estate | 2009 |
| Tarar Capital Ltd | Construction | 2025 |
| Targets Venture Ltd | Other services | 2022 |
| Tarmin Solutions Limited | Information & communication | 2000 |
| Taskgenie Ltd | Administrative & support | 2024 |
| Taskher Ltd | Information & communication | 2021 |
| Tasksnest Limited | Information & communication | 2026 |
| Tasty Kebabish Limited | Hospitality | 2022 |
| Tata Autos Ltd | Wholesale & retail | 2026 |
| Tayoldo Pharma Limited | Wholesale & retail | 2017 |
| Tbrown Constructions Limited | Administrative & support | 2025 |
| Tbsa Limited | Hospitality | 2025 |
| TBT Homes Ltd | Real estate | 2026 |
| TCT Assistance Humanitaire Ltd | Professional & scientific | 2025 |
| Teamwear KIT Limited | Wholesale & retail | 2026 |
| Tech Armors Ltd | Professional & scientific | 2023 |
| Tech Hub Solutions Limited | Wholesale & retail | 2023 |
| Techboost Studios Ltd | Information & communication | 2025 |
| Technik Motors Ltd | Wholesale & retail | 2018 |
| Technology School of Tecsa Ltd | Education | 2025 |
| Technolology School of Tecsa Ltd | Education | 2025 |
| Techspell Ltd | Information & communication | 2024 |
| Techspire Solutions Ltd | Wholesale & retail | 2025 |
| Techsystem Services Ltd | Information & communication | 2017 |
| TED Building Service Ltd | Construction | 2021 |
| TEE Dairy Ltd | Wholesale & retail | 2026 |
| TEE Styleit UK Limited | Wholesale & retail | 2021 |
| Telrad Limited | Health & social care | 2022 |
| Temple Cash and Carry International Bazaar Import and Export Limited | Wholesale & retail | 2020 |
| Templemore Holdings Limited | Financial services | 2025 |
| Temtem Care Ltd | Administrative & support | 2025 |
| TEN Plus 888 Ltd | Information & communication | 2025 |
| TEN Talk Ltd | Wholesale & retail | 2025 |
| Tera Tera London Ltd | Real estate | 2026 |
| Terabit IT Ltd | Information & communication | 2024 |
| Tessellate Accessories Ltd | Wholesale & retail | 2022 |
| Tetrad Assets Capital Ltd | Real estate | 2026 |
| Texture Rolled Limited | Extraterritorial | 1980 |