| Solutions 4 Office Limited | Wholesale & retail | 2006 |
| SOLUTN247 Limited | Transport & logistics | 2022 |
| Solyra Systems Ltd | Information & communication | 2025 |
| Soma SRI Limited | Real estate | 2015 |
| Somali Faces Ltd | Health & social care | 2016 |
| Somalinimo UK CIC | Arts & recreation | 2025 |
| Somatic Wellness Project CIC | Health & social care | 2025 |
| Somerlake Services Ltd | Construction | 2025 |
| Sommer City Limited | Transport & logistics | 2025 |
| Sommerville Kent Ltd | Health & social care | 2009 |
| Somnluna Ltd | Wholesale & retail | 2025 |
| Somsos Limited | Wholesale & retail | 2025 |
| Sonargaon Leather Export Ltd | Wholesale & retail | 2024 |
| Songbird Estates Ltd | Real estate | 2026 |
| Songbird Leisure Ltd | Arts & recreation | 2022 |
| Sonia O'Donnell Native Wisdom Limited | Administrative & support | 2020 |
| Sonmatias Ltd | Households | 2026 |
| Sonocraft Innovations Ltd | Education | 2025 |
| Sons and Daughters of the King Ltd | Health & social care | 2019 |
| Sophia Global Limited | Information & communication | 2026 |
| Sophie Baker Performance Coaching Ltd | Health & social care | 2026 |
| Sophie Dalzell Limited | Arts & recreation | 2018 |
| Sophie Developments Limited | Real estate | 2019 |
| Sophie Online Limited | Information & communication | 2018 |
| Sophosys Ltd | Information & communication | 2024 |
| Sopretty@ Limited | Administrative & support | 2017 |
| Sora Nutrition Limited | Other services | 2024 |
| Sorchi Healthcare Ltd | Administrative & support | 2019 |
| Sorella DEL Mare Ltd | Wholesale & retail | 2025 |
| Sormac Ltd | Wholesale & retail | 2023 |
| Soro Studio Ltd | Professional & scientific | 2018 |
| Sorted Cars Ltd | Information & communication | 2026 |
| Sorted Trader Ltd | Information & communication | 2026 |
| Sortpad Limited | Hospitality | 1989 |
| Sosban Consulting Limited | Professional & scientific | 2017 |
| Soseri Limited | Health & social care | 2019 |
| Soul Garden Therapy Ltd | Health & social care | 2020 |
| Souliga Ltd | Professional & scientific | 2024 |
| Soulln Ltd | Professional & scientific | 2025 |
| Soulwood Arts Education Ltd | Education | 2025 |
| Sound and Music Isolation Matters Ltd | Wholesale & retail | 2025 |
| Sound Mind Body Wellbeing CIC | Health & social care | 2025 |
| Sound Revel Limited | Information & communication | 2019 |
| Soundbite Advisory Ltd | Manufacturing | 2026 |
| Soundly Fostering Ltd | Health & social care | 2021 |
| Source of Life Ltd | Administrative & support | 2016 |
| Source One Associates Limited | Professional & scientific | 2019 |
| Source One Consulting Ltd | Construction | 2002 |
| Source One Property Limited | Real estate | 2014 |
| Sourcecodecreative Limited | Information & communication | 2024 |
| Sourcecodestudio Limited | Information & communication | 2016 |
| Sourcewell Property Limited | Real estate | 2025 |
| South Entrance Homes Limited | Construction | 2025 |
| South Norfolk Homes Ltd | Real estate | 2018 |
| South Suffolk Agricultural Association Limited | Other services | 1998 |
| South West Changeovers Limited | Administrative & support | 2021 |
| South West London Racing Limited | Arts & recreation | 2024 |
| Southall TV Ltd | Information & communication | 2012 |
| Southern Access Limited | Professional & scientific | 2008 |
| Southern Cross International Limited | Financial services | 2015 |
| Southern Discomfort Ltd | Arts & recreation | 2013 |
| Southwest Solar & Renewables Limited | Energy | 2025 |
| Sovereign Court Cricket Field Management Company Ltd | Professional & scientific | 2013 |
| Sovereign Estates Group Limited | Real estate | 2020 |
| Sovereignty Capital Alliance Limited | Financial services | 2024 |
| SOW & Grow Essex CIC | Education | 2026 |
| Soyandbeecandles Limited | Manufacturing | 2024 |
| SP E2 Limited | Professional & scientific | 2015 |
| SP SWE Services Ltd | Information & communication | 2022 |
| Spa Paraplanning Limited | Professional & scientific | 2025 |
| Spaade Ltd | Real estate | 2023 |
| Space by Design Limited | Real estate | 2016 |
| Space for Research | Professional & scientific | 2024 |
| Space Inc Ltd | Construction | 2013 |
| Space Renovations Dorset Ltd | Construction | 2025 |
| Space Slug Games Ltd | Manufacturing | 2023 |
| Space Systems Furniture Ltd | Manufacturing | 2018 |
| Spacepay Limited | Administrative & support | 2025 |
| Span Life Ltd | Information & communication | 2024 |
| Spanhaus Ltd | Education | 2022 |
| Spapb Limited | Real estate | 2019 |
| Spaplus Ltd | Other services | 2019 |
| Spargo Ltd | Health & social care | 2025 |
| Sparhawk Management Company Limited | Households | 1983 |
| Spark Initiatives Limited | Professional & scientific | 2026 |
| Sparkle Like a Diamond Ltd | Administrative & support | 2020 |
| Sparkline Construction Ltd | Construction | 2024 |
| Sparkmind Ltd | Health & social care | 2025 |
| Sparky Solutions Group Limited | Construction | 2026 |
| Spartan Installations Limited | Administrative & support | 2020 |
| Spartan Red Property Limited | Real estate | 2024 |
| Spartan Test Solutions Limited | Information & communication | 2013 |
| Spasis Ltd. | Health & social care | 2002 |
| Spavellous Limited | Information & communication | 2021 |
| Spawn Developments Limited | Information & communication | 2026 |
| SPD Legacy Holdings Ltd | Real estate | 2024 |
| Speak of the Ltd. | Information & communication | 2020 |
| Special Products Group Ltd | Professional & scientific | 2023 |
| Specialist Air Integration and Tactical Solutions Limited | Public administration | 2022 |
| Specialist IT Solutions Ltd | Information & communication | 2015 |