| Sonya Ltd | Construction | 2010 |
| Sophie Goodchild Communications Limited | Other services | 2012 |
| Soul Contract Connect Limited | Information & communication | 2015 |
| Soul Monks Ltd | Other services | 2022 |
| Soule Wallace Limited | Professional & scientific | 2025 |
| Soulinc Limited | Real estate | 2021 |
| Soulmate Homes Ltd | Real estate | 2019 |
| Sound Tailor Events Ltd | Arts & recreation | 2025 |
| Sourcekey Property Ltd | Real estate | 2023 |
| Sourcewise Tech Solutions UK Limited | Information & communication | 2024 |
| South Asian Social Limited | Other services | 2025 |
| South Bucks Effluent Company Limited | Water & waste | 2013 |
| South City Films Limited | Information & communication | 2016 |
| South Coast Care Homes Limited | Health & social care | 2015 |
| South Coast Property Investments Limited | Real estate | 2019 |
| South East Holdings Limited | Financial services | 2019 |
| South East Housing Limited | Professional & scientific | 1996 |
| South Norwood Properties Limited | Real estate | 2025 |
| South Surma Limited | Extraterritorial | 2010 |
| Southbank and General Investments Limited | Construction | 1982 |
| Southern Spices Limited | Hospitality | 2017 |
| Southerton 1 Ltd | Administrative & support | 2015 |
| Southwest Locum Services Limited | Health & social care | 2005 |
| Southwestern General Property Co. Limited | Real estate | 1968 |
| Souvlamaster UK Ltd | Wholesale & retail | 2026 |
| Soyuz Investments Limited | Administrative & support | 2009 |
| Soyuz Properties Limited | Real estate | 2012 |
| SP Digital Innovation Ltd | Information & communication | 2018 |
| SP JAG Ltd | Professional & scientific | 2015 |
| SP3 Worldwide Limited | Information & communication | 2012 |
| Space Apart Hotel Limited | Professional & scientific | 2015 |
| Spaceagent Architects Limited | Professional & scientific | 2006 |
| Spaceagent MAS Ltd | Professional & scientific | 2016 |
| SPACESCIENCE360 Ltd | Professional & scientific | 2026 |
| Spanheath Limited | Financial services | 1974 |
| Spar Clean Car Valet Ltd | Wholesale & retail | 2014 |
| Spark AI Studios Ltd | Administrative & support | 2025 |
| Spark Pack Ltd | Wholesale & retail | 2025 |
| Spark Smiles Ltd | Professional & scientific | 2020 |
| Sparkle and Shine Cleaning Products Limited | Wholesale & retail | 2023 |
| Sparkle and Shine Detailing Limited | Administrative & support | 2013 |
| Sparkle and Shine Valeting and Detailing Limited | Administrative & support | 2014 |
| Sparq Investments Limited | Real estate | 2022 |
| Sparrowhawk Services Limited | Information & communication | 2005 |
| Sparv Investment Limited | Real estate | 2018 |
| Sparv Solutions PVT Ltd | Information & communication | 2015 |
| Speakers Global Bureau Ltd | Extraterritorial | 2017 |
| Specialised Equipment Limited | Administrative & support | 2012 |
| Specoptics Ltd | Wholesale & retail | 2025 |
| Spectrm Ltd | Information & communication | 2025 |
| Speech and Language Techniques Ltd | Health & social care | 2023 |
| Speedtec Limited | Wholesale & retail | 2024 |
| Spencer Home UK Limited | Real estate | 2007 |
| Spencer House Management (Wimbledon) Limited | Households | 1975 |
| Spherical Limited | Information & communication | 2016 |
| Spinney Advisory Limited | Real estate | 2021 |
| Splash P&H Limited | Wholesale & retail | 2023 |
| Spoilt Rotten Dog Ltd | Other services | 2025 |
| Spondon Investments LLP | | 2017 |
| Sports Capital Inc Limited | Wholesale & retail | 2024 |
| Sports Software Ltd | Information & communication | 2024 |
| Sprava Ltd | Real estate | 2023 |
| Sprin United Limited | Real estate | 2021 |
| Springlife Trading Limited | Hospitality | 2009 |
| Springwood FMC Ltd | Information & communication | 2018 |
| Springwood UK Services Limited | Professional & scientific | 2025 |
| Sprout Supplements Ltd | Manufacturing | 2026 |
| Sptl Solutions Ltd | Construction | 2025 |
| SPU Investments Ltd | Real estate | 2022 |
| Spyentist Limited | Information & communication | 2024 |
| Square Mile Developments Ltd | Real estate | 1998 |
| Squires Service Solutions Ltd | Professional & scientific | 2022 |
| SR Holdings Limited | Real estate | 2018 |
| SR Learning Ltd | Professional & scientific | 2021 |
| SR N Construction Ltd | Construction | 2024 |
| SRD Management Consulting Limited | Information & communication | 2018 |
| SRI Chakra Jewels Ltd | Manufacturing | 2022 |
| Sritharan Ventures Limited | Transport & logistics | 2025 |
| SRL N Solutions Ltd | Construction | 2023 |
| SRM Electrical Film & Lighting Ltd | Construction | 2024 |
| SRM Investments Limited | Real estate | 1998 |
| SRP Cash and Carry Ltd | Wholesale & retail | 2025 |
| Srrs Capital Ltd | Real estate | 2023 |
| SRS Realty Ltd | Real estate | 2021 |
| Srsa Consulting Limited | Administrative & support | 2012 |
| SS Accounting Services Limited | Professional & scientific | 2015 |
| SS Centre Limited | Health & social care | 2020 |
| SS Distributors Global Limited | Wholesale & retail | 2023 |
| SSK Practice Ltd | Health & social care | 2024 |
| Ssnk Property Ltd | Real estate | 2025 |
| SSS Construction Ltd | Construction | 2020 |
| ST Albans Tuition Limited | Education | 2016 |
| ST Andrews House Crawley Ltd | Construction | 1992 |
| ST Electricals (UK) Limited | Manufacturing | 2013 |
| ST Francis College Limited | Education | 2022 |
| ST Francis Pewsey Nursery Limited | Education | 2025 |
| ST Francis School Limited | Education | 2024 |
| ST James Estates Limited | Construction | 2013 |
| ST Matthew's Montessori School Ltd. | Education | 2014 |
| ST. Christopher's School (Private) Limited | Education | 1979 |