| SKW Properties Ltd | Real estate | 2019 |
| Skweeker Garden Design Services Limited | Administrative & support | 2003 |
| Skylark Management Company Limited | Households | 2017 |
| Skyscraper Media Ltd | Professional & scientific | 2026 |
| Skyscraper Services Ltd | Professional & scientific | 2024 |
| Skyshot Global Limited | Professional & scientific | 2016 |
| Slaley Hall Lodges Title Limited | Professional & scientific | 2019 |
| Slide Clinic Digital Ltd | Information & communication | 2018 |
| Sliggy Limited | Arts & recreation | 2024 |
| SLM Property Management Services Ltd | Households | 2026 |
| Sloth Social Ltd | Professional & scientific | 2026 |
| SLV8 Limited | Professional & scientific | 2014 |
| SM Plumbing & Heating Ltd | Construction | 2023 |
| Smart Boat Limited | Manufacturing | 2023 |
| Smart Candle Global Ltd | Extraterritorial | 2020 |
| Smart Programmes Ltd | Professional & scientific | 2021 |
| Smart PVT Ltd | Information & communication | 2021 |
| Smart Roof Repairs Ltd | Construction | 2025 |
| Smart Safe Ltd | Information & communication | 2020 |
| Smart Way Building & Property Services Ltd | Construction | 2025 |
| SMART4DMIN Ltd | Administrative & support | 2024 |
| Smartcrutch Ltd | Wholesale & retail | 2018 |
| Smartgoodsservices Ltd | Wholesale & retail | 2026 |
| Smartops AI Ltd | Professional & scientific | 2025 |
| Smartworks Automotive Limited | Extraterritorial | 2002 |
| Smartworks Repair POD Limited | Extraterritorial | 2018 |
| Smash ALL Burgers Ltd | Hospitality | 2021 |
| SMD Investments Limited | Real estate | 2013 |
| SME Ventures Ltd | Professional & scientific | 2021 |
| Smitcare Ltd | Wholesale & retail | 1998 |
| Smith Institute | Professional & scientific | 1997 |
| Smiths Homes London Ltd | Real estate | 2025 |
| SMJ Media Group CIC | Information & communication | 2022 |
| SMS Group UK. Ltd | Wholesale & retail | 1994 |
| Snapped UP Studios Limited | Arts & recreation | 2023 |
| Snm-Chp Limited | Wholesale & retail | 2025 |
| Snug & Bean Ltd | Wholesale & retail | 2026 |
| SNV Logistics Ltd | Transport & logistics | 2011 |
| SNW Business Services Limited | Professional & scientific | 1998 |
| SO ME Nutrition Ltd | Health & social care | 2017 |
| Sobti Distribution Limited | Wholesale & retail | 2015 |
| Soccerxp Ltd | Professional & scientific | 2024 |
| Social Care Research Ltd | Professional & scientific | 2024 |
| Social Impact Co-Investment Fund LP | | 2011 |
| Socom Tactical Limited | Wholesale & retail | 2009 |
| Sofiejones Ltd | Wholesale & retail | 2024 |
| Software Impact Limited | Information & communication | 2009 |
| Soho Caffe Camberley Limited | Hospitality | 2019 |
| Sois Ltd | Arts & recreation | 2022 |
| Solar Insight Limited | Construction | 2023 |
| Solar Sidewalks Ltd | Manufacturing | 2020 |
| Solavana Ltd. | Professional & scientific | 2015 |
| Sole Pine Media Ltd | Information & communication | 2018 |
| Solid Instal System Ltd | Construction | 2026 |
| Solidity Software Ltd | Information & communication | 2024 |
| Solitra OY | | 1995 |
| Solo Nutrition Limited | Wholesale & retail | 1999 |
| Solo Old Skool Ravers Ltd | Wholesale & retail | 2024 |
| Soloi Ltd | Information & communication | 2022 |
| Solsil Ltd | Administrative & support | 2021 |
| SOLUTIONS4SPORT & Physical Education Ltd | Education | 2014 |
| Sommervelt (Alice Holt) Limited | Extraterritorial | 2015 |
| Sommervelt Limited | Professional & scientific | 2013 |
| SON Antem Nominees Limited | Professional & scientific | 2012 |
| SON of Thunder Publications Ltd | Information & communication | 2014 |
| Sonas Health Limited | Health & social care | 2025 |
| Sond Enterprises Limited | Health & social care | 2014 |
| Sond Properties Limited | Real estate | 2013 |
| Sonesfelt Ltd | Real estate | 2025 |
| Sonning Riverside Park Limited | Households | 2022 |
| SOO Yeah Studio Ltd | Professional & scientific | 2018 |
| Sophilive Properties Limited | Real estate | 2020 |
| Sorted and Sparkling Ltd | Administrative & support | 2026 |
| Soteria Protection Services Ltd | Administrative & support | 2023 |
| Soundscoop Limited | Information & communication | 2018 |
| Source Office Supplies Limited | Wholesale & retail | 2005 |
| Source Supplies Limited | Extraterritorial | 2020 |
| Sourced Asset Ltd | Financial services | 2019 |
| Sourced LUX Ltd | Wholesale & retail | 2025 |
| South Asian Cultural Circle Ltd | Education | 2023 |
| South East Waterway Services Ltd | Transport & logistics | 2021 |
| South Farnborough Construction & Landscaping Ltd | Construction | 2024 |
| South Group Holdings Ltd | Agriculture & fishing | 2015 |
| South PLY Limited | Wholesale & retail | 2019 |
| South Ridge Land Limited | Extraterritorial | 2010 |
| South West Steels Limited | Wholesale & retail | 2003 |
| South Winchester Operations Limited | Arts & recreation | 2019 |
| South Winchester Property Limited | Real estate | 1993 |
| Southdart Ltd | Other services | 1996 |
| Southeast Air Ltd | Administrative & support | 2015 |
| Southern Despatch Couriers Ltd | Transport & logistics | 2013 |
| Southern Glazing Limited | Construction | 2025 |
| Southern Power Limited | Construction | 2023 |
| Southern Road Camberley Limited | Real estate | 2025 |
| Southfield Estates Limited | Households | 1999 |
| Southfile Properties (Basingstoke) Limited | Construction | 1976 |
| Sovereign Court (Reading) Limited | Households | 2014 |
| Sovereign Court (Tilehurst) Management Company Limited | Households | 2002 |
| Sovereign Roofing Ltd | Construction | 2025 |
| Sowerbutts and Co. Limited | Professional & scientific | 1999 |