| Shreeji Estate Limited | Real estate | 2019 |
| Shreejicare Limited | Other services | 2010 |
| Shrewsbury Group Ltd | Wholesale & retail | 2021 |
| Shri Group of Business Ltd | Administrative & support | 2025 |
| Shri Munnadiyan Limited | Wholesale & retail | 2026 |
| Shrirag Holdings PVT Ltd | Financial services | 2017 |
| Shubh Double Glazing Limited | Construction | 2025 |
| Shubh Homes Ltd | Real estate | 2026 |
| Shutrak Global Limited | Other services | 2018 |
| Shwish Ltd | Information & communication | 2026 |
| Shyam Dhani Ltd | Wholesale & retail | 2025 |
| Shyambis International Ltd | Real estate | 2018 |
| Siam Massage Ltd | Other services | 2011 |
| Siba Estates Limited | Real estate | 2025 |
| Siben Limited | Real estate | 2005 |
| Sicimoglu Limited | Health & social care | 2013 |
| Sicimoglu Property Ltd | Real estate | 2023 |
| Siddh Constructions Limited | Construction | 2013 |
| Siddh Glazing Ltd | Construction | 2020 |
| Siddika Services Ltd | Professional & scientific | 2025 |
| Sidekick Management Limited | Arts & recreation | 2004 |
| Sidhu Villa UK Ltd | Real estate | 2025 |
| Sidof Trans Ltd | Transport & logistics | 2022 |
| Sidtheamae Limited | Health & social care | 2013 |
| Sienna Kaur Gill Limited | Real estate | 2022 |
| Sienna’S Sunshine Early Years Ltd | Education | 2025 |
| Sierra's Eastern Europe Limited | Wholesale & retail | 2026 |
| Siftag Ltd | Information & communication | 2026 |
| Sigesttrans Ltd | Transport & logistics | 2018 |
| Sigi Food and Drink Ltd | Wholesale & retail | 2024 |
| Signal Visiontech Ltd | Information & communication | 2025 |
| Signature Concept Events Ltd | Hospitality | 2026 |
| Signature Etch Ltd | Wholesale & retail | 2026 |
| Signature Fragrances London Limited | Wholesale & retail | 2017 |
| Signature Law Limited | Professional & scientific | 2021 |
| Signature Recording Studios Ltd | Information & communication | 2020 |
| Signature Shopfitters Ltd | Construction | 2016 |
| Signature Staffing Solutions Limited | Transport & logistics | 2025 |
| Significant Bullet Productions Limited | Information & communication | 2016 |
| Sihota Consulting Limited | Information & communication | 2014 |
| Sika Security Ltd | Administrative & support | 2021 |
| Sikandar Ralh Ltd | Construction | 2020 |
| Sikka Construction Ltd | Construction | 2023 |
| Silk Construction Ltd | Construction | 2023 |
| Silk Studio LDN Ltd | Other services | 2025 |
| Silks Aesthetics Ltd | Other services | 2024 |
| Silly Midon Limited | Professional & scientific | 2002 |
| SILOAM:256 C.I.C. | Education | 2022 |
| Silver Cactus Productions Ltd | Information & communication | 2020 |
| Silver Facades Ltd | Construction | 2019 |
| Silver Fjord Software Ltd | Information & communication | 2025 |
| Silver Oak Holdings Ltd | Real estate | 2016 |
| Silver Star Cars Limited | Administrative & support | 2021 |
| Silver Torch Limited | Transport & logistics | 2023 |
| Silverhook Holdings Limited | Financial services | 2017 |
| Silverhook Ltd. | Administrative & support | 1991 |
| Silverstone Medical Supplies Ltd | Health & social care | 2017 |
| Silverstones Group Ltd | Education | 2023 |
| Silvervine Limited | Real estate | 1987 |
| Silvia Craft Ltd | Construction | 2021 |
| Sim's Cloud Kitchen Limited | Hospitality | 2026 |
| Simac Ventures Limited | Health & social care | 2013 |
| Simage Communications Limited | Information & communication | 1985 |
| Simarcore Group Ltd | Transport & logistics | 2026 |
| Simbog Ltd | Construction | 2021 |
| Simia Farra and Company Limited | Professional & scientific | 2009 |
| Simia Farra Holdings Limited | Financial services | 2024 |
| Simion Site Services Ltd | Construction | 2015 |
| Simmontham Services Ltd | Wholesale & retail | 2022 |
| Simms Sweet London Limited | Wholesale & retail | 2026 |
| Simon Carpentry Ltd | Construction | 2017 |
| Simon Hills Estates Limited | Real estate | 2020 |
| Simon Nuel Ltd | Wholesale & retail | 2021 |
| Simon Property Services Ltd | Real estate | 2019 |
| Simple Skip Services Ltd | Construction | 2020 |
| Simplex Fire and Security Ltd | Administrative & support | 2023 |
| Simply Asia Romford Ltd | Hospitality | 2016 |
| Simply Black ASH Limited | Households | 1994 |
| Simply Consultancy LDN Ltd | Professional & scientific | 2025 |
| Simply Exports Ltd | Professional & scientific | 2010 |
| Simply Mortgages Limited | Financial services | 2019 |
| Simply Panda Ltd | Administrative & support | 2022 |
| Simply South Ltd | Extraterritorial | 2025 |
| Simply the Best Trade Ltd | Wholesale & retail | 2019 |
| Simplyservices Tech Ltd | Other services | 2025 |
| Simpson Seating Ltd | Manufacturing | 2026 |
| Simraj Services Ltd | Health & social care | 2023 |
| Simsend Support Network CIC | Education | 2026 |
| Simsol Technologies Limited | Information & communication | 2016 |
| Simtik Limited | Professional & scientific | 2011 |
| Sinai Investments Limited | Health & social care | 2008 |
| Sinclar Estates Limited | Real estate | 2021 |
| Sinden Estates LLP | | 2005 |
| Sinden Holdings Limited | Financial services | 2020 |
| Sineview Group Limited | Professional & scientific | 2024 |
| Sineview Limited | Information & communication | 2019 |
| Singapore Finance Law Ltd | Financial services | 2023 |
| Singcerity Ltd | Health & social care | 2021 |
| Singh Assets Limited | Real estate | 2026 |
| Singh Shopfitter Ltd | Construction | 2026 |