| Sculpture ME Limited | Other services | 2025 |
| Sdcubed Properties Ltd | Real estate | 2025 |
| SDT Information Solutions Limited | Professional & scientific | 2016 |
| Sea Lion Group Limited | Administrative & support | 2002 |
| Sea Management Ltd | Professional & scientific | 2019 |
| Sea Road Developments Ltd | Construction | 2017 |
| Sean Corr Joinery Limited | Manufacturing | 2003 |
| Seashell Sports Limited | Arts & recreation | 2022 |
| Season Shop Ltd | Wholesale & retail | 2023 |
| Seclec Homes Limited | Hospitality | 2015 |
| Seclec Limited | Manufacturing | 2012 |
| Secure Ground Transportation Limited | Transport & logistics | 2018 |
| Secure Land Developments Limited | Construction | 1999 |
| Secure Land Investments Limited | Real estate | 1999 |
| Secure Land Limited | Real estate | 1998 |
| Secure Maintenance Limited | Manufacturing | 2022 |
| Secure Properties Limited | Real estate | 2006 |
| Secure That JOB Ltd | Administrative & support | 2020 |
| Selarep Limited | Professional & scientific | 2018 |
| Select Building & Maintenance Services Ltd | Construction | 2013 |
| Select SKI Limited | Administrative & support | 2011 |
| Select Star From Limited | Information & communication | 2025 |
| Selor Ltd | Wholesale & retail | 2025 |
| Semper Services Ltd | Administrative & support | 2016 |
| Sensing Solutions International Limited | Construction | 2019 |
| Sensing Solutions Limited | Administrative & support | 2019 |
| Senteria Ltd | Construction | 2013 |
| Sentinel Academy Ltd | Education | 2011 |
| Sentinel Group of Companies Ltd | Financial services | 2005 |
| Sentinel Group Security Limited | Administrative & support | 2005 |
| Sentinel Technologies Ltd | Information & communication | 2012 |
| Service Offset Supplies Group Limited | Financial services | 2023 |
| Service Offset Supplies Holdings Limited | Financial services | 2016 |
| Service Offset Supplies Limited | Wholesale & retail | 1972 |
| Setform Limited | Manufacturing | 1982 |
| Setlo Limited | Construction | 2010 |
| Seven 98 Limited | Administrative & support | 2023 |
| Seven Star Pro Car Hire Ltd | Administrative & support | 2023 |
| Sevissmaster Ltd | Information & communication | 2019 |
| Sevon Investments Ltd | Real estate | 2025 |
| Seyhan Limited | Information & communication | 2012 |
| SF Fintech Services Limited | Information & communication | 2015 |
| SF Wood Ltd | Professional & scientific | 2026 |
| SGB Venture Holdings Limited | Professional & scientific | 2003 |
| Sgch Services Limited | Professional & scientific | 2025 |
| Sgt-Risk Management Limited | Administrative & support | 2025 |
| SH Ceiling & Partition Ltd | Construction | 2026 |
| Shad Thames Property Limited | Real estate | 2026 |
| Shadona Limited | Hospitality | 2010 |
| Shadow Proclamation Limited | Administrative & support | 2023 |
| Shaira Properties Limited | Real estate | 2026 |
| Shancome Construction Limited | Construction | 2006 |
| Shangri-La Ltd | Hospitality | 2023 |
| Sharada Consulting Limited | Information & communication | 2011 |
| Sharp Futures Limited | Financial services | 2002 |
| Sharpe and Sharpe Ltd | Real estate | 2015 |
| Sharps Move Solutions Ltd | Transport & logistics | 2013 |
| Sharps Workplace Services Ltd | Administrative & support | 2025 |
| Shavonne Ltd | Wholesale & retail | 2022 |
| Shaws Electrical Solutions Ltd | Construction | 2024 |
| Sheehan Trading Ltd | Wholesale & retail | 2020 |
| Sheen Publishing Limited | Information & communication | 1981 |
| Shekinah Footwear Ltd | Wholesale & retail | 2019 |
| Shelax Ltd | Wholesale & retail | 2026 |
| Shelley Court (Southgate) Management Company Limited | Households | 1993 |
| Shenley Developments Limited | Construction | 2015 |
| Sherringham Court Management Company Limited | Real estate | 1983 |
| Shift Marketing W12 Ltd | Wholesale & retail | 2024 |
| Shimin Ltd | Wholesale & retail | 2025 |
| Shine Fostering Limited | Health & social care | 2012 |
| Shine GAS and Heating Limited | Construction | 2020 |
| Shiney S&G Limited | Financial services | 2021 |
| Shiplake Meadows Limited | Real estate | 2018 |
| Shiraz Design Limited | Wholesale & retail | 2022 |
| Shire Properties (South East) Limited | Real estate | 1997 |
| Shire Transit Limited | Transport & logistics | 2017 |
| Shiva Enterprise Limited | Wholesale & retail | 2024 |
| SHM Enforcement Limited | Administrative & support | 2022 |
| Shoaib Saleem Ltd | Professional & scientific | 2012 |
| Shore and Flow Ltd | Administrative & support | 2025 |
| Shore House Management Ltd | Professional & scientific | 2018 |
| Shore Waters Management Company Limited | Households | 2003 |
| Shorram Limited | Wholesale & retail | 2011 |
| Shot Coffee Ltd | Hospitality | 2018 |
| Show Skin Aesthetics Ltd | Health & social care | 2025 |
| Shrubs Management Company (Woodford Green) Limited(The) | Households | 1983 |
| Shuangdi Europe Ltd | Manufacturing | 2025 |
| SI Belle Care Ltd | Health & social care | 2019 |
| SI Consultancy Management Ltd | Professional & scientific | 2021 |
| Sial Networks Limited | Information & communication | 2021 |
| Sian Aherne PR Limited | Professional & scientific | 2015 |
| SID Lahiri Consulting Limited | Financial services | 2020 |
| Sidan Investment Property Limited | Construction | 2015 |
| Sidan Trading Holdings Limited | Administrative & support | 2017 |
| Sidan Trading Property Limited | Construction | 2015 |
| Sidney COX Consultancy Services Limited | Extraterritorial | 2017 |
| Sidney UK Car Ltd | Other services | 2022 |
| Siem Estates Limited | Construction | 2012 |
| Siem Residential Limited | Real estate | 2014 |
| Sierra SAM Ltd | Arts & recreation | 2020 |