| Stone's Throw (Bembridge) Limited | Real estate | 2021 |
| Stonehenge Estates Limited | Construction | 2020 |
| Strands Hair Salon Ltd | Other services | 2013 |
| Stratland Commercial Limited | Real estate | 2017 |
| Stratland Estates Limited | Construction | 2015 |
| Stratland Holdings Limited | Financial services | 2017 |
| Stratland Homes Ltd | Construction | 2025 |
| Stratland Properties Limited | Real estate | 2024 |
| Stratos Refurbishments Ltd | Construction | 2026 |
| Strevens Roofing and Building Limited | Construction | 2025 |
| Strive and Thrive Recruitment Solutions Ltd | Administrative & support | 2023 |
| Strong Finish Ltd | Construction | 2021 |
| Strong Gynaecology Ltd | Health & social care | 2024 |
| Strong Path CIC | Arts & recreation | 2024 |
| Structure QSR Professional Services Ltd | Construction | 2021 |
| Strutech Limited | Professional & scientific | 2010 |
| Stuart Keith Roofing Company Limited | Construction | 1997 |
| Studio Republic Limited | Extraterritorial | 2007 |
| Stylebest Marketing Limited | Administrative & support | 1997 |
| Suan Thai Ltd | Hospitality | 2019 |
| SUB ARB Limited | Administrative & support | 2010 |
| Sub-Sub Sandwich Co. Ltd | Wholesale & retail | 2026 |
| Suddern Farm Residents Company Limited | Real estate | 1991 |
| Sugavi Petrol Two Ltd | Wholesale & retail | 2024 |
| Sula's Property Rental Ltd | Households | 2014 |
| Sulborne Sewerage Services Ltd | Water & waste | 2023 |
| Summit Stonemasons Ltd | Construction | 2024 |
| Summit Tutors Limited | Education | 2021 |
| Sunbeam Watercress Limited | Agriculture & fishing | 1962 |
| Sunnyside House RTM Company Ltd | Households | 2026 |
| Sunrise Farm Limited | Construction | 2003 |
| Sunrise Landscapes Ltd | Administrative & support | 2020 |
| Sunrise Tools & Equipment Ltd | Wholesale & retail | 1997 |
| Sunshine Management Services Limited | Health & social care | 2014 |
| Suppscore Limited | Health & social care | 2026 |
| Surfeit Solutions Ltd | Administrative & support | 2020 |
| Surrey LOG Cabins Limited | Construction | 2020 |
| Susanne Boswell Garden Design Limited | Professional & scientific | 2023 |
| Sushi Media Limited | Professional & scientific | 2020 |
| Sussex HIP & Knee Limited | Health & social care | 2022 |
| Sutra Mela Ltd | Professional & scientific | 2025 |
| Swam Limited | Real estate | 2011 |
| Swedish Baking Studio Ltd | Manufacturing | 2024 |
| Sweeny Barber Ltd | Other services | 2020 |
| Sweeny Barber Romsey Limited | Other services | 2026 |
| Sweet Cicely Nutrition Ltd | Health & social care | 2025 |
| Swift Build Developments Limited | Construction | 2016 |
| Swillex Ltd | Professional & scientific | 2024 |
| Swing Dance Partnerships Limited | Education | 2018 |
| Syncoline Limited | Wholesale & retail | 2000 |
| Synergy for Growth Ltd | Professional & scientific | 2021 |
| Synergy Portfolio Limited | Real estate | 2005 |
| Szymaniak Digital Limited | Professional & scientific | 2026 |
| T & Play Hub Limited | Hospitality | 2022 |
| T & S Accountants & Business Advisors Ltd | Professional & scientific | 2003 |
| T D Urology Limited | Health & social care | 2019 |
| T J Investments Ltd | Real estate | 2010 |
| T S Spinal Limited | Health & social care | 2014 |
| T W F C Limited | Professional & scientific | 2003 |
| T&B Motorsport Projects Ltd | Professional & scientific | 2023 |
| T&S Scott Holdings Limited | Financial services | 2017 |
| T-Minus 10 Ltd | Arts & recreation | 2021 |
| T.A. Spacagna Limited | Manufacturing | 1996 |
| T63 Limited | Professional & scientific | 2022 |
| Tafl Research Ltd | Professional & scientific | 2025 |
| Tagmax Ltd | Administrative & support | 2018 |
| Tailor Care Southampton Limited | Health & social care | 2016 |
| Tailored Costs Limited | Professional & scientific | 2010 |
| Tailored Tech Labs Ltd | Information & communication | 2026 |
| Takeaway Food Limited | Hospitality | 2011 |
| Talking Products Limited | Manufacturing | 2002 |
| Talwar Medical Services Limited | Health & social care | 2016 |
| Tambu Healthcare Ltd | Health & social care | 2014 |
| Tanya Trading Ltd | Information & communication | 2024 |
| Taotek Limited | Information & communication | 2013 |
| Tarrell Medical Services Limited | Health & social care | 2022 |
| Tava Limited | Information & communication | 2020 |
| Tax & Strategy EZT Limited | Extraterritorial | 2018 |
| Tax & Strategy Limited | Extraterritorial | 2021 |
| Tax-Business Limited | Professional & scientific | 2011 |
| Taycliff Limited | Information & communication | 2005 |
| Tayles Hill House RTM Company Ltd | Households | 2025 |
| Taylor & Townsend Consulting Limited | Professional & scientific | 2015 |
| Taylor Made Automotive Limited | Wholesale & retail | 2016 |
| Taylor Medical Ltd | Health & social care | 2021 |
| TBS Planning Ltd | Professional & scientific | 2023 |
| TCM Packaging Limited | Financial services | 2023 |
| TCM Print London Limited | Financial services | 2023 |
| TD Action Performance Ltd | Arts & recreation | 2022 |
| TD Urology Care LLP | | 2025 |
| TDQ Limited | Real estate | 2016 |
| Team Futwiz Esports Ltd | Information & communication | 2019 |
| Team-In-A-Box Limited | Professional & scientific | 2013 |
| Teamshift UK Limited | Administrative & support | 2017 |
| Teamtask Limited | Financial services | 2015 |
| TECH4 Residential Ltd | Real estate | 2014 |
| Technigraphics Systems Limited | Administrative & support | 1981 |
| Tehshipway Limited | Professional & scientific | 2023 |
| Temple Court House (Romsey) Management Company Limited | Households | 2017 |
| Tennett Trading Limited | Wholesale & retail | 2010 |