| Sustainable Financial Markets Limited | Other services | 2021 |
| Sustainable Hub Ltd | Wholesale & retail | 2023 |
| Sustainable Resources International Limited | Professional & scientific | 1997 |
| Sustineri Partners Limited | Professional & scientific | 2021 |
| Sutterby Investments Ltd | Financial services | 2006 |
| Sutton T4 Ltd | Manufacturing | 2021 |
| SUV600 Ltd | Real estate | 2014 |
| SUV601 Limited | Real estate | 2022 |
| SW Cleaning Services Ltd | Administrative & support | 2014 |
| Swan Dove Ltd | Hospitality | 2022 |
| Sway Cycles Ltd | Extraterritorial | 2020 |
| Sweetspot Limited | Households | 2009 |
| Swell Pictures Limited | Information & communication | 2002 |
| Swing N Buy Ltd | Wholesale & retail | 2024 |
| SWL Gymnastics Ltd | Education | 2017 |
| Swole Entertainment Limited | Information & communication | 2026 |
| Sycamore Place (Edenbridge) Management Limited | Households | 2006 |
| Sylk Limited | Wholesale & retail | 1996 |
| Sylvatica Ecology Ltd | Professional & scientific | 2011 |
| Sylvie Flais Limited | Health & social care | 2013 |
| Symax Ltd | Professional & scientific | 2017 |
| Syncrowear London Ltd | Wholesale & retail | 2026 |
| Synergie Exploration UK Limited | Financial services | 2026 |
| Synergie Property Ltd | Real estate | 2019 |
| Syrox Limited | Information & communication | 2015 |
| Syslabs Ltd | Information & communication | 2010 |
| System Serve Ltd. | Administrative & support | 2002 |
| Syyco Limited | Information & communication | 2008 |
| T & T Service UK Ltd | Administrative & support | 2013 |
| T Brown Investments Limited | Real estate | 2019 |
| T Cash Landscaping & Garden Maintenance Ltd | Administrative & support | 2021 |
| T I D Ltd | Transport & logistics | 2016 |
| T M Forensics Ltd | Professional & scientific | 2011 |
| T&A UK Group Ltd | Real estate | 2025 |
| T.Hourican (Scuk London) Ltd | Professional & scientific | 2021 |
| T4KT Ltd | Wholesale & retail | 2019 |
| TA Healthcare Limited | Administrative & support | 2010 |
| TA Legal & Management Services Ltd | Professional & scientific | 2026 |
| Tabard House RTM Company Limited | Households | 2021 |
| Tablebridge Limited | Administrative & support | 1987 |
| Taco Bite Ltd | Hospitality | 2024 |
| Tactile Cafe Ltd | Hospitality | 2026 |
| Tadamon | Health & social care | 2025 |
| Tafelberg Limited | Information & communication | 2015 |
| TAG HV Test Limited | Professional & scientific | 2018 |
| Tagetik UK Limited | Professional & scientific | 2008 |
| Tahi One Ltd | Real estate | 2020 |
| Tahoe East Ltd | Other services | 2022 |
| Tailpin Holdings Ltd | Arts & recreation | 2021 |
| Take Notice Apparel Limited | Wholesale & retail | 2025 |
| Talbot Scott Affinity Limited | Real estate | 2006 |
| Talbot Scott Ltd. | Real estate | 1987 |
| Talbot Scott Marketing Ltd. | Real estate | 2009 |
| Talent Acquisition Advisors Ltd | Administrative & support | 2024 |
| Tame Consulting Limited | Information & communication | 2006 |
| Tang Wealth UK Ltd | Wholesale & retail | 2023 |
| Tangerine Fields Ltd | Hospitality | 2004 |
| Tani Building Ltd | Construction | 2025 |
| Tantrum Epsom Ltd | Other services | 2024 |
| Tantrum Group Limited | Financial services | 2025 |
| Tantrum Hair Extensions Epsom Ltd | Other services | 2025 |
| Tantrum Hair Extensions Guildford Ltd | Other services | 2025 |
| Tantrum Hair Extensions Kingston Ltd | Other services | 2025 |
| Tantrum Kingston Ltd | Other services | 2025 |
| Tantrum Solutions Limited | Information & communication | 2009 |
| Tantrum Store Ltd | Other services | 2026 |
| Tanya Hairdressing Ltd | Other services | 2017 |
| Tanzell Limited | Professional & scientific | 2008 |
| Tanzilaa Banu Hilal Ahamed Ltd | Wholesale & retail | 2024 |
| Taradin House Ltd | Real estate | 2023 |
| Tarawhiti UK Ltd | Construction | 2024 |
| Target House Management Limited | Households | 2021 |
| Tartan Duck Limited | Information & communication | 2007 |
| Tashi Electrical Ltd | Construction | 2025 |
| Task Electrical Services Ltd | Construction | 2017 |
| Tasker & Najman Limited | Professional & scientific | 2010 |
| Tasty Bite Surbiton Ltd | Hospitality | 2025 |
| TAV Bridges (UK) Limited | Professional & scientific | 2004 |
| Tavington Limited | Information & communication | 2016 |
| Tavtech Ltd | Information & communication | 2024 |
| Tax NL Limited | Professional & scientific | 2025 |
| Taxfreeman Ltd | Professional & scientific | 2019 |
| Taylor T Limited | Hospitality | 2003 |
| TB Technical Services Limited | Professional & scientific | 2019 |
| Tbhff Limited | Hospitality | 2019 |
| TBS Business Group Ltd | Education | 2019 |
| TC Freehold Management Ltd | Households | 2025 |
| TCB Entertainment Ltd | Administrative & support | 2024 |
| Tcsj Consultancy Ltd | Professional & scientific | 2013 |
| TD Digital Consult Ltd | Information & communication | 2018 |
| Teach 360 Limited | Administrative & support | 2017 |
| Teale Technology Ltd | Professional & scientific | 2025 |
| Team Medical Ltd | Administrative & support | 2005 |
| Teamform UK Ltd | Information & communication | 2023 |
| Teamwork Commerce Limited | Wholesale & retail | 2020 |
| Teaura Foods and Drinks Limited | Wholesale & retail | 2026 |
| Tech Forty Two Ltd | Information & communication | 2019 |
| Tech Kingston Ltd | Wholesale & retail | 2025 |
| Tech Recipes Ltd | Professional & scientific | 2015 |
| Tech-Engage Ltd | Information & communication | 2015 |