| Strategic BID Consulting Limited | Professional & scientific | 2020 |
| Strategic Business Solutions Ltd | Professional & scientific | 2008 |
| Strategic Legacy Ltd | Other services | 2026 |
| Strategic Management Holdings Ltd | Professional & scientific | 2022 |
| Strategic Management Services Ltd | Professional & scientific | 2019 |
| Strategic Project Partners Limited | Professional & scientific | 2005 |
| Strategic Targets Limited | Professional & scientific | 2015 |
| Strategic Vision Partners Limited | Information & communication | 2025 |
| Strategy Consultant Designers Limited | Professional & scientific | 2003 |
| Strengthbox Limited | Arts & recreation | 2014 |
| Stretton Residents Association Limited | Real estate | 1998 |
| Stride Ventures Ltd | Real estate | 2024 |
| Striide Studio Limited | Wholesale & retail | 2025 |
| Struthane Limited | Health & social care | 2022 |
| STS Instruments Limited | Manufacturing | 2008 |
| Stuart Fraser Refining Consultancy Limited | Professional & scientific | 2012 |
| Stuart Rawlins Limited | Professional & scientific | 2019 |
| Studio 35 Limited | Manufacturing | 2007 |
| Studio 41 Ltd | Wholesale & retail | 2024 |
| Studio 9 Fitness Ltd | Arts & recreation | 2021 |
| Studio Forme Limited | Professional & scientific | 2024 |
| Studio Pepper Ltd | Professional & scientific | 2024 |
| Stunt Courses Ltd | Arts & recreation | 2020 |
| Success With Numbers Limited | Professional & scientific | 2014 |
| Success With Properties Limited | Construction | 2026 |
| Sudvig Enterprises Limited | Wholesale & retail | 2017 |
| Suffolk Close Management Co.(Slough)Limited | Households | 1973 |
| Sugar Bliss Ltd | Wholesale & retail | 2023 |
| Sugatsune Kogyo (UK) Limited | Wholesale & retail | 2005 |
| Sukki Consultancy Limited | Information & communication | 2015 |
| Sulis Fine Art Ltd | Wholesale & retail | 2014 |
| Sullivan's Organised Living Ltd | Other services | 2025 |
| Summit Exterior Cleaning Ltd | Administrative & support | 2024 |
| Sumoka Consulting Limited | Professional & scientific | 2016 |
| Sumoka Health Ltd | Health & social care | 2023 |
| Sumoka Property Services Ltd | Real estate | 2016 |
| Sun Shed Ltd | Health & social care | 2014 |
| Sunalytix Ltd | Information & communication | 2026 |
| Sunbird Europe Limited | Manufacturing | 2013 |
| Suncrown Limited | Manufacturing | 2022 |
| Sunlight Personal Assistance Ltd | Health & social care | 2026 |
| Sunning House Management Limited | Households | 1991 |
| Sunninghill General Trading Company Limited | Administrative & support | 2014 |
| Sunshine Gardening Services Ltd | Other services | 2003 |
| Sunshine Landscaping Services Ltd | Other services | 2003 |
| Sunspire Consulting Limited | Information & communication | 2008 |
| Sunweb Computing Limited | Information & communication | 2013 |
| Superlative Solutions Ltd | Professional & scientific | 2003 |
| Supersonic Motors Limited | Wholesale & retail | 2026 |
| Supervision Psychotherapy and Counselling Education Services (Spaces) Limited | Health & social care | 2024 |
| Supply PER Demand Ltd | Wholesale & retail | 2024 |
| Support Horizons Community Interest Company | Health & social care | 2006 |
| Support Star Limited | Professional & scientific | 2011 |
| Supportive AID for Everyone Ltd | Public administration | 2020 |
| Supreme Houses UK Ltd | Construction | 2009 |
| Supremeprize Ltd | Wholesale & retail | 2023 |
| Suravani Services Limited | Real estate | 2023 |
| Surdhar Properties Limited | Real estate | 2016 |
| Surelock Group Limited | Professional & scientific | 2002 |
| Surelock Mcgill Group Limited | Professional & scientific | 2002 |
| Surelock Mcgill Limited | Manufacturing | 1961 |
| Surtees Holdings Limited | Professional & scientific | 1958 |
| Sushi Point Wokingham Ltd | Wholesale & retail | 2025 |
| Sustainable Urban Solutions Limited | Professional & scientific | 2017 |
| Sustainz Ltd | Construction | 2025 |
| Suvarna Lakshmi Ltd | Information & communication | 2024 |
| Suzie Mutch Ltd | Professional & scientific | 2018 |
| Svark Estates Ltd | Real estate | 2025 |
| Svark Solutions Ltd | Information & communication | 2022 |
| SW Property & Development Ltd | Real estate | 2024 |
| Swan Valley Lakes Ltd | Agriculture & fishing | 2023 |
| Swanley Real Estate Limited | Construction | 2025 |
| Swap | Professional & scientific | 1974 |
| Swap (One) Limited | Professional & scientific | 2005 |
| Swift Cars (Wokingham) Limited | Transport & logistics | 2017 |
| Swift Events Ltd | Hospitality | 2025 |
| Swift House RTM Company Limited | Households | 2025 |
| Swift Pour UK Limited | Other services | 2022 |
| Swim Bebe Limited | Wholesale & retail | 2025 |
| Swiri Ltd | Professional & scientific | 2026 |
| Swisship Limited | Professional & scientific | 2019 |
| Sycom Limited | Information & communication | 1999 |
| Syed Ansari Limited | Hospitality | 2023 |
| Sylvester Close Residents Association Limited | Households | 1997 |
| Synaform Limited | Professional & scientific | 2025 |
| Synergy House UK Limited | Wholesale & retail | 2024 |
| Synergy Medical Europe Limited | Wholesale & retail | 2017 |
| Systemxl Ltd | Construction | 2018 |
| Szentesi Ltd. | Information & communication | 2025 |
| T Borrett Limited | Construction | 2016 |
| T Brickwork and Building Limited | Construction | 2021 |
| T C C Peek Ltd | Wholesale & retail | 2005 |
| T Mcfadden Holdings Ltd | Administrative & support | 2022 |
| T Squared Consultancy Limited | Professional & scientific | 2013 |
| T W Jobs Ltd | Administrative & support | 2019 |
| T.D. Ceramics Limited | Health & social care | 2004 |
| T.S. (Renovations) Limited | Construction | 1979 |
| T3 New Limited | Professional & scientific | 2025 |
| T5 OIL & GAS Gabon Limited | Mining & quarrying | 2014 |
| T5 OIL & GAS Holding Guinea Limited | Financial services | 2014 |