| Soundarya by Jasmine Ltd | Wholesale & retail | 2025 |
| Soundbite Music Ltd | Information & communication | 2025 |
| Soundklouda Ltd | Arts & recreation | 2024 |
| Soundmonger Ltd | Information & communication | 2012 |
| Soundright Limited | Real estate | 2015 |
| Sounds ST Leonards Ltd | Arts & recreation | 2025 |
| Soupysip Ltd | Hospitality | 2025 |
| Sourcepro Design Ltd | Professional & scientific | 2021 |
| South Asian Event Limited | Other services | 2025 |
| South Central Project Limited | Information & communication | 2019 |
| South Durham Supply Company Limited | Professional & scientific | 1933 |
| South East Bubbles Ltd | Administrative & support | 2024 |
| South East Ventures Ltd | Construction | 2013 |
| South Enterprize Ltd | Professional & scientific | 2016 |
| South Harrow Food & Wine Ltd | Wholesale & retail | 2023 |
| South Harrow Food Centre Ltd | Wholesale & retail | 2024 |
| South Harrow Food Ltd | Wholesale & retail | 2026 |
| South Harrow Fruit & Vege Ltd | Wholesale & retail | 2018 |
| South Harrow Halal Meat Ltd | Wholesale & retail | 2023 |
| South Harrow Homebase Ltd | Wholesale & retail | 2025 |
| South Harrow Kebabish Limited | Hospitality | 2025 |
| South Harrow Market Ltd | Real estate | 2020 |
| South Harrow Pharmacy Limited | Wholesale & retail | 2024 |
| South Hill Estates,Harrow,Limited(The) | Real estate | 1910 |
| South Hill Lodge Limited | Households | 1988 |
| South Indies Ltd | Hospitality | 2022 |
| South Norwood M.O.T. Test Centre Limited | Administrative & support | 2010 |
| South Space Studios Ltd | Professional & scientific | 2022 |
| Southacre Properties Limited | Real estate | 2025 |
| Southall Businesses CIC | Administrative & support | 2026 |
| Southall Heights Limited | Construction | 2024 |
| Southall Rights Limited | Professional & scientific | 1981 |
| Southcrest Care 2 Ltd | Health & social care | 2023 |
| Southcrest Care Ltd | Health & social care | 2016 |
| Southden Holdings Limited | Financial services | 2023 |
| Southden Limited | Health & social care | 2012 |
| Southdown Business Solutions Ltd | Administrative & support | 2013 |
| Southdowns Consultancy Limited | Professional & scientific | 2007 |
| Southern Cold Ltd | Professional & scientific | 2020 |
| Southern International Limited | Other services | 2023 |
| Southern Record Distributors Limited | Wholesale & retail | 1987 |
| Southern Stocktakers LLP | | 2021 |
| Southern Yacht Charter Limited | Administrative & support | 2008 |
| Southgate Commercial Property Ltd | Real estate | 2024 |
| Southlands Court Care Homes Limited | Health & social care | 2007 |
| Southlands Nursing Home Holdings Limited | Health & social care | 2025 |
| Southold Ltd | | 2015 |
| Southover Day Nursery Ltd | Education | 2021 |
| Southquay Property Ltd | Real estate | 2010 |
| Southwark Park Nursing Homes Limited | Health & social care | 1996 |
| Southway Properties Limited | Real estate | 2022 |
| Southwest 2 Orthodontists Limited | Financial services | 2024 |
| Southwest Orthodontists Limited | Health & social care | 2017 |
| Southwest Projects Limited | Construction | 2022 |
| Southwest Property Developments Limited | Real estate | 2021 |
| Souza.M Property Services Ltd | Real estate | 2018 |
| Sovereign BCH Ltd | Hospitality | 2026 |
| Sovereign Digital Media Ltd | Information & communication | 2024 |
| Sovereign Exclusive Homes Ltd | Construction | 2014 |
| Sovereign Film Nominees Limited | Administrative & support | 2001 |
| Sovereign Inc Ltd | Professional & scientific | 2020 |
| Sovereign Investments Group Limited | Financial services | 2016 |
| Sovereign Lending Ltd | Professional & scientific | 2025 |
| Sovereign Park (Basildon) Management Limited | Real estate | 2003 |
| Sovereign Safe Deposit Centres (Harrow) Limited | Transport & logistics | 2014 |
| Sovereign Sewing Machines (Rental) Limited | Administrative & support | 1987 |
| SOW & Reap Ltd. | Financial services | 2014 |
| Sowdown Limited | Professional & scientific | 2009 |
| Sower Creative Limited | Information & communication | 2024 |
| Sowmya Soft Ltd | Information & communication | 2016 |
| SOX Properties Limited | Real estate | 2020 |
| Soyuz Minicoaches Ltd | Transport & logistics | 2012 |
| Sozo Care Limited | Health & social care | 2023 |
| SP Beauty Chiswick Ltd | Other services | 2024 |
| SP Business Advisors Ltd | Professional & scientific | 2025 |
| SP Dent Ltd | Health & social care | 2018 |
| SP Fire Limited | Construction | 2017 |
| SP Global Consultancy Limited | Information & communication | 2024 |
| SP Import Export Ltd | Transport & logistics | 2010 |
| SP Notary Public Ltd | Professional & scientific | 2023 |
| SP Quality Consulting Ltd | Professional & scientific | 2016 |
| SP Short Stays Ltd | Real estate | 2023 |
| SP Tradelink Ltd | Wholesale & retail | 2025 |
| SP UK International Limited | Wholesale & retail | 2025 |
| SP33 Films Ltd | Information & communication | 2022 |
| Spaark Ventures Ltd | Other services | 2023 |
| Spaas Ltd | Professional & scientific | 2024 |
| Space Merchants Events Ltd | Arts & recreation | 2020 |
| Space Merchants Ltd | Professional & scientific | 2009 |
| Space Professionals Partnership Limited | Professional & scientific | 2023 |
| Space Project Management UK Ltd | Construction | 2007 |
| Space Synapse Systems Ltd | Professional & scientific | 2010 |
| Space Ventura Ltd | Real estate | 2026 |
| Spacebar Developments Ltd | Real estate | 2022 |
| Spacebond Limited | Real estate | 1999 |
| Spacecentral Residents Management Limited | Real estate | 1988 |
| Spacehopper Studios Limited | Information & communication | 2004 |
| Spacev Limited | Construction | 2022 |
| Spakhaney's Limited | Health & social care | 2025 |
| Spam Property Limited | Real estate | 2015 |