| Sudharsan Consulting Limited | Professional & scientific | 2015 |
| Suite Cribs Ltd | Real estate | 2022 |
| Sumal & Sons (Properties) Limited | Real estate | 1991 |
| Sumal Property Limited | Real estate | 1998 |
| Sumar Supplies Limited | Wholesale & retail | 2011 |
| Sun Real Estate Ltd | Real estate | 2011 |
| Sunkissed Potters Bar Ltd | Other services | 2023 |
| Sunkissed Tanning and Beauty Salon Limited | Other services | 2014 |
| Sunny Side UP Stories Ltd | Information & communication | 2026 |
| Sunrise Investments RE Ltd | Administrative & support | 2017 |
| Sunshine Retail Ltd | Wholesale & retail | 2024 |
| Super Play Media Ltd | Information & communication | 2024 |
| Superlative Sets Limited | Administrative & support | 2025 |
| Supernacular Limited | Wholesale & retail | 2021 |
| Supersaver Limited | Administrative & support | 2014 |
| Supple Transport Limited | Transport & logistics | 1999 |
| Support for Gdpr Ltd | Information & communication | 2018 |
| Supreme Decor Ltd | Construction | 2024 |
| Supreme Textiles Limited | Professional & scientific | 2004 |
| Sure Call Recruitment Services Ltd | Administrative & support | 2004 |
| Sure Care Solutions Limited | Health & social care | 2004 |
| Surge and Falter Limited | Arts & recreation | 2008 |
| Surhas Homes Limited | Real estate | 2021 |
| Suroar Ltd | Real estate | 2026 |
| Surrey Motors Limited | Real estate | 1919 |
| Susayjb Medical Care Limited | Health & social care | 2019 |
| SVN Financial Limited | Financial services | 2024 |
| Swan Lodge and Mews Management Ltd | Households | 2020 |
| Swapology Ltd | Professional & scientific | 2011 |
| Swi&P Limited | Financial services | 2021 |
| Swift Contact Limited | Extraterritorial | 2015 |
| Swift Neuro Consulting Ltd | Professional & scientific | 2024 |
| Swiftcat Associates Limited | Professional & scientific | 2015 |
| Switch Hustle Records Limited | Information & communication | 2018 |
| Syncbubble.Com Ltd | Administrative & support | 2012 |
| Synthesis Architecture and Wellbeing Limited | Professional & scientific | 2020 |
| Synthessa Ltd | Administrative & support | 2025 |
| System Uvex Limited | Manufacturing | 1987 |
| T & J Malin Limited | Wholesale & retail | 2024 |
| T a P Medical Services Limited | Health & social care | 2019 |
| T Baker Limited | Manufacturing | 2021 |
| T E Waltho Ltd | Other services | 2024 |
| T&T IT Limited | Information & communication | 2018 |
| T. Barnfield Limited | Transport & logistics | 2008 |
| T.A.D. Enterprises Limited | Professional & scientific | 2000 |
| T.E.D. (Recruitment) Limited | Administrative & support | 1991 |
| T.M.E.A Properties Limited | Real estate | 2024 |
| T.S.G. Building Services PLC | Construction | 2000 |
| T8 Productions Ltd | Information & communication | 2025 |
| T8 Property Limited | Real estate | 2024 |
| TA Academy Limited | Other services | 2023 |
| Taask Limited | Administrative & support | 2025 |
| TAB X Tech Ltd | Professional & scientific | 2024 |
| Tabitha Perry Limited | Arts & recreation | 2022 |
| Tachyon Wholesale Ltd | Wholesale & retail | 2024 |
| Taha Elite Limited | Information & communication | 2021 |
| Tahu Contracting Limited | Administrative & support | 2007 |
| Talent Edge Europe Limited | Education | 2007 |
| TAM Invest Properties UK Ltd | Financial services | 2024 |
| Tamtar Ltd | Information & communication | 2011 |
| Tanalytics Limited | Professional & scientific | 2011 |
| Tanita Build Ltd | Construction | 2023 |
| Tanjameh Limited | Wholesale & retail | 2018 |
| Tanya Melamori Ltd | Information & communication | 2024 |
| Tark Group Limited | Information & communication | 2022 |
| Taskelion Ltd | Information & communication | 2025 |
| Taskelium Ltd | Information & communication | 2025 |
| Tassia Limited | Wholesale & retail | 1945 |
| Tasva Ltd | Hospitality | 2024 |
| Tate Developments Limited | Real estate | 1999 |
| Tattooed Sports Limited | Wholesale & retail | 2026 |
| Taurus Designs Ltd | Professional & scientific | 2016 |
| Tavernaki Limited | Hospitality | 2013 |
| Tax Accounting Services Limited | Professional & scientific | 2023 |
| Taylor James Resourcing Limited | Administrative & support | 2005 |
| TBR Industries Limited | Administrative & support | 2010 |
| Tcmlawconsult Ltd | Professional & scientific | 2022 |
| Tcsa Cleaning Limited | Administrative & support | 2024 |
| Tcsa Property Limited | Real estate | 2023 |
| Tdsl Ltd | Other services | 2019 |
| Team Hall Limited | Real estate | 2021 |
| Team Property Solutions Limited | Real estate | 2018 |
| TEC Euphoria Limited | Information & communication | 2007 |
| Tech Software Solutions Ltd | Information & communication | 2014 |
| Tech This Ltd | Wholesale & retail | 2025 |
| Techbridge Ltd | Information & communication | 2014 |
| Technical Feet Ltd | Professional & scientific | 2020 |
| Techquified Ltd | Professional & scientific | 2020 |
| Tecnocap UK Ltd | Administrative & support | 2015 |
| Tecpaq Limited | Administrative & support | 2007 |
| Tecra Global Limited | Construction | 2010 |
| Tedale Properties Limited | Real estate | 1998 |
| TEE Global Limited | Professional & scientific | 2025 |
| Teebeedee Group Ltd | Professional & scientific | 2022 |
| Tele Ticket Limited | Information & communication | 2002 |
| Telecom Spares Limited | Information & communication | 2007 |
| Telos T&G Limited | Financial services | 2024 |
| Tempo Training 100 Ltd | Other services | 2016 |
| TEN Fifty Five Limited | Arts & recreation | 2012 |
| TEN Kings Ltd | Wholesale & retail | 2017 |