| Sustainable Energy Alternative Solutions Limited | Water & waste | 2012 |
| Svfx Limited | Information & communication | 2009 |
| SWD Bespoke Ltd | Wholesale & retail | 1999 |
| SWD Property Limited | Real estate | 2016 |
| Swinley Consulting Limited | Construction | 2024 |
| Swinley Forest Golf Club Limited | Hospitality | 2008 |
| Swinley Laser Clinic Ltd | Other services | 2021 |
| Swynford Advisory Limited | Professional & scientific | 2022 |
| Syed Shah Construction Limited | Construction | 2025 |
| Sylvan Lynchet Limited | Real estate | 1988 |
| T & G Wholesale Meats Limited | Wholesale & retail | 2001 |
| T Q Hair Design Limited | Other services | 2001 |
| T Shooter & Associates Limited | Professional & scientific | 2015 |
| T&T Trade Solutions Limited | Administrative & support | 2012 |
| T.C. Communications Limited | Professional & scientific | 1985 |
| Taalim Ltd | Administrative & support | 2014 |
| Table & Taps Ltd | Hospitality | 2025 |
| Tactic Games UK Ltd | Wholesale & retail | 2006 |
| Takasago (U.K.) Limited | Wholesale & retail | 1990 |
| Talent Management Seminars Limited | Professional & scientific | 1989 |
| Talkington Bates Limited | Hospitality | 2000 |
| Talkington Bates Management Services LLP | | 2008 |
| Tamare House Limited | Health & social care | 2020 |
| Tameshi Ltd | Information & communication | 2022 |
| Taran Property Group Ltd | Real estate | 2022 |
| Tashan Investments Limited | Real estate | 2015 |
| Taste of 5 Rivers Ltd | Hospitality | 2025 |
| Tavistock Asset Management Limited | Financial services | 2021 |
| Tavistock Chater Allan LLP | | 2021 |
| Tavistock Essentials Limited | Financial services | 2024 |
| Tavistock Group Holdings Limited | Financial services | 2016 |
| Tavistock Intermediate Holdco Limited | Financial services | 2026 |
| Tavistock Investments PLC | Professional & scientific | 2004 |
| Tavistock Partners (UK) Ltd | Financial services | 2003 |
| Tavistock Private Client Limited | Financial services | 2001 |
| Tavistock Select LLP | | 2022 |
| Tavistock Services Limited | Administrative & support | 2014 |
| TC Communications Holdings Limited | Professional & scientific | 2008 |
| TC Equestrian Ltd | Agriculture & fishing | 2026 |
| TDS Consulting Ltd | Professional & scientific | 2013 |
| TEC Software Services Ltd | Information & communication | 2017 |
| TEC Software Solutions Limited | Information & communication | 2014 |
| Technetic Solutions Limited | Information & communication | 2006 |
| Techwass Consulting Limited | Information & communication | 2014 |
| Teddy&Co Ltd | Wholesale & retail | 2022 |
| Tekifi UK Limited | Professional & scientific | 2026 |
| Telecoms Traders Ltd | Wholesale & retail | 2014 |
| Temis & Frei Associates Limited | Administrative & support | 2005 |
| Tempo Energy Ltd | Extraterritorial | 2024 |
| Tenderpreneurs Ltd | Information & communication | 2025 |
| Tepe Kimya Europe Ltd | Manufacturing | 2014 |
| Terra Verde Homes Limited | Construction | 2026 |
| Tessa Corr Associates Limited | Professional & scientific | 2005 |
| TEXT121CHAT Limited | Information & communication | 2003 |
| TGH Films Limited | Information & communication | 2015 |
| Thai Serenesolution UK Ltd | Administrative & support | 2026 |
| THE Accordion Shop Ltd | Extraterritorial | 2013 |
| THE Alternative Travel Awards Limited | Other services | 2006 |
| THE Ascot Glade Property Limited | Households | 2023 |
| THE Ascot Partnership Limited | Professional & scientific | 2010 |
| THE Asters (Sunningdale) Management Company Limited | Households | 2012 |
| THE Aura Group LLP | | 2005 |
| THE Bar Guys (UK) Limited | Hospitality | 2015 |
| THE Beeches Worthing Limited | Health & social care | 1995 |
| THE Blow Code Limited | Wholesale & retail | 2025 |
| THE Build Group Ascot Ltd | Construction | 2024 |
| THE Cape Academy Limited | Education | 2016 |
| THE Clarendon Clinic Limited | Wholesale & retail | 2025 |
| THE Coaching Option Ltd | Administrative & support | 2019 |
| THE Combes Golf Park Limited | Arts & recreation | 2023 |
| THE Cooling Team Ltd | Construction | 2024 |
| THE Cosmetic Clinic UK Limited | Professional & scientific | 2007 |
| THE DEV Centre Limited | Information & communication | 2013 |
| THE Evolution Business Limited | Administrative & support | 2018 |
| THE Facialist Ascot Ltd | Other services | 2026 |
| THE Fit Face Club Limited | Health & social care | 2012 |
| THE Flare Group Limited | Manufacturing | 2017 |
| THE Four Winds Partnership Limited | Professional & scientific | 2009 |
| THE Fourth Room Contracts Ltd | Administrative & support | 2011 |
| THE Fourth Room Property Services Ltd | Administrative & support | 2013 |
| THE Frances Johnstone Legacy Limited | Education | 1959 |
| THE Game Day (UK) Ltd | Professional & scientific | 2021 |
| THE Garden House (Sunningdale) Management Company Limited | Households | 2004 |
| THE Ginger FIG Club Ltd | Other services | 2021 |
| THE Great British Bubbles Ltd | Wholesale & retail | 2017 |
| THE Green Block Consulting Ltd | Professional & scientific | 2018 |
| THE Heathfield Fellowship | Education | 2009 |
| THE High Group London Ltd | Construction | 2022 |
| THE Ironing Service Ascot Ltd | Administrative & support | 2019 |
| THE Kennel Avenue Management Company Limited | Real estate | 1994 |
| THE Kingfisher Profile Management Ltd | Professional & scientific | 2025 |
| THE Maas Gallery Holdings Limited | Financial services | 2021 |
| THE Maas Gallery Limited | Wholesale & retail | 1993 |
| THE Marist School (Ascot) Limited | Education | 2022 |
| THE Meadow Martins Lane Ltd | Households | 2024 |
| THE Nags Head Sunningdale Limited | Hospitality | 2021 |
| THE New Foundry Limited | Administrative & support | 2026 |
| THE Nextpath Device Consortium CIC | Information & communication | 2025 |
| THE One Factory Limited | Professional & scientific | 2017 |
| THE Organic BRA Company Limited | Manufacturing | 2013 |