| SWC Transport Limited | Administrative & support | 2016 |
| Swedish Monkey Ltd | Information & communication | 2025 |
| Sweet and Tidy Ltd | Wholesale & retail | 2025 |
| Sweet Intelligence UK Limited | Information & communication | 2026 |
| Swift Herl Ltd | Administrative & support | 2021 |
| Swift Meds Online (UK) Ltd | Wholesale & retail | 2026 |
| Swift Property Lettings Ltd | Real estate | 2010 |
| Swiftcartpc Ltd | Wholesale & retail | 2025 |
| Swim Generation Limited | Education | 2012 |
| Swim Vision Limited | Education | 2025 |
| Swimpod Global Limited | Manufacturing | 2026 |
| Swishforit Ltd | Information & communication | 2019 |
| Swiss Bread (UK) Limited | Manufacturing | 2015 |
| Swiss Kitchen Limited | Hospitality | 2025 |
| SWL Consultants Ltd | Professional & scientific | 2019 |
| SWL Fringe Ltd | Administrative & support | 2018 |
| Sync Traffic Solutions Ltd | Construction | 2024 |
| Synergy Inspection Services Ltd | Professional & scientific | 2020 |
| SYNERGYX4 Ltd | Hospitality | 2025 |
| Syntexia.Ai Ltd | Information & communication | 2025 |
| Synthetique Ltd | Professional & scientific | 2025 |
| Syon Group Ltd | Financial services | 2016 |
| Systra Scott Lister UK Limited | Professional & scientific | 2010 |
| Syzo Media Limited | Information & communication | 2015 |
| SZ Technology Solutions Ltd | Information & communication | 2015 |
| T & T Global Ltd | Real estate | 2012 |
| T a Joinery & Carpentry Ltd | Construction | 2025 |
| T J Greenhalgh Ltd | Information & communication | 2019 |
| T-Infra GES Ltd | Financial services | 2024 |
| T-Infra Global Ltd | Health & social care | 2019 |
| T-Infra RBJ Ltd | Financial services | 2024 |
| T-Infra UMJ Ltd | Financial services | 2024 |
| T-Infra UMS Ltd | Financial services | 2024 |
| T.B. Tarn Limited | Administrative & support | 2010 |
| T.B.Earle(Farms)Limited | Agriculture & fishing | 1964 |
| T.H.Properties(Richmond)Limited | Households | 1959 |
| T.J Farms Limited | Agriculture & fishing | 2008 |
| T.P. Atkinson Limited | Agriculture & fishing | 2002 |
| T6 Developments Limited | Construction | 2026 |
| Tabula Rasa Holdings Limited | Financial services | 2021 |
| TAC Electrics Ltd | Construction | 2023 |
| Tacklelit Ltd | Information & communication | 2019 |
| Taco London Ltd. | Construction | 2022 |
| Tail Feather Interiors Limited | Construction | 2015 |
| Tailored Search Limited | Arts & recreation | 2009 |
| Tailsco Limited | Wholesale & retail | 2013 |
| Takayama Ltd | Hospitality | 2010 |
| Takes Group Ltd | Information & communication | 2026 |
| Taketwo Retail Ltd | Wholesale & retail | 2022 |
| Talbot Blonde Bombshell Limited | Hospitality | 2017 |
| Talent Films Limited | Extraterritorial | 1996 |
| Talent TV and Music Ltd | Information & communication | 2001 |
| Talfourd Developments Limited | Construction | 2022 |
| Talfourd Holdings Limited | Financial services | 2022 |
| Talkeasy Limited | Wholesale & retail | 1996 |
| Tambling Creates Ltd | Manufacturing | 2022 |
| Tanasoft Ltd | Information & communication | 2017 |
| Tancred Farms Limited | Agriculture & fishing | 2020 |
| Tancred Gravel Limited | Mining & quarrying | 1953 |
| Tangier Road Flats (Management Company) Limited | Real estate | 2006 |
| Tango Romeo Uniform Echo Limited | Extraterritorial | 2011 |
| Tania Trading Limited | Wholesale & retail | 2025 |
| Tao’S Tees Ltd | Wholesale & retail | 2026 |
| Tarapatha Limited | Professional & scientific | 2017 |
| Tartan Pro Tour Limited | Arts & recreation | 2020 |
| Tash Nicou Limited | Information & communication | 2021 |
| Taste of Sicilia Limited | Hospitality | 2012 |
| Taste of Trinacria Ltd | Hospitality | 2020 |
| Tastetactics Limited | Professional & scientific | 2024 |
| Tasty Macs Limited | Hospitality | 2019 |
| Tavaktech Ltd | Information & communication | 2025 |
| Tavares Media Ltd | Arts & recreation | 2013 |
| Taverner Consultancy Limited | Information & communication | 2013 |
| Tavira Development Limited | Financial services | 2026 |
| Taxagility Limited | Professional & scientific | 2010 |
| Taxo'D Limited | Professional & scientific | 2015 |
| Taylor Bros (Richmond) Limited | Agriculture & fishing | 2020 |
| Taylored Business Secretaries Limited | Administrative & support | 2009 |
| Taylored Business Services Limited | Extraterritorial | 2009 |
| Taylormade HTG and Plumbing Ltd | Construction | 2025 |
| TB SPV1 Limited | Construction | 2014 |
| Tbhv Consultants Limited | Professional & scientific | 2023 |
| TBR Phase 3 Limited | Households | 2006 |
| Tbvgc Ltd | Wholesale & retail | 2023 |
| TCC Pavilion Limited | Arts & recreation | 2018 |
| TCL Family Limited | Financial services | 2025 |
| TCM Consultant Services Ltd | Professional & scientific | 2026 |
| TDE Developments Limited | Real estate | 2018 |
| TDS Catering Ltd | Hospitality | 2019 |
| TE Investments Ltd | Real estate | 2006 |
| Tea&Cheese Ltd | Professional & scientific | 2019 |
| Team 2 Telecommunications Limited | Professional & scientific | 1994 |
| Team Chapman Trading Limited | Agriculture & fishing | 2016 |
| Tearspoint Limited | Wholesale & retail | 2014 |
| Teatone Limited | Wholesale & retail | 2016 |
| Technik (UK) Ltd | Wholesale & retail | 2015 |
| Technological Tailors Ltd | Wholesale & retail | 2018 |
| Techsembly Limited | Information & communication | 2021 |
| TED 'N' IVY Limited | Real estate | 2018 |
| Teds Deli Ltd | Wholesale & retail | 2025 |