| Silver Cafe Services Limited | Hospitality | 2025 |
| Silver Capital Management Ltd | Real estate | 2021 |
| Silver Facilities Management Limited | Wholesale & retail | 2020 |
| Silver Gallery Ltd | Manufacturing | 2021 |
| Silver Mobile Car Valeting Limited | Administrative & support | 2010 |
| Silver One (London) Limited | Professional & scientific | 2007 |
| Silver Rock Entertainment Ltd | Arts & recreation | 2025 |
| Silver Service Cafe Limited | Hospitality | 2025 |
| Silvercrest Energy Group Ltd | Energy | 2011 |
| Silvercrest Scaffolding Ltd | Construction | 2012 |
| Silvercrest Security Services Ltd | Administrative & support | 2011 |
| Silverdale Infill Property Limited | Construction | 2025 |
| Silvermantle Ltd | Professional & scientific | 2005 |
| Silvermere Consulting Limited | Information & communication | 2015 |
| Silvermere International Limited | Information & communication | 2020 |
| Silverr Ltd | Construction | 2020 |
| Silversonic Ltd | Manufacturing | 2025 |
| Silviu Candle of Hope Ltd | Water & waste | 2024 |
| Silviu Cleaning Limited | Administrative & support | 2025 |
| Simad Payroll Limited | Administrative & support | 2014 |
| Simad Publications Limited | Information & communication | 2007 |
| Simeonov G Ltd | Construction | 2025 |
| Simistar Limited | Transport & logistics | 2019 |
| Simon & Co Properties Ltd | Real estate | 2025 |
| Simon Hamilton Limited | Other services | 2017 |
| Simon Holloway Building Solutions Ltd | Construction | 2020 |
| Simon Kimbangu Foundation | Other services | 2019 |
| Simple and Chic Limited | Wholesale & retail | 2013 |
| Simple Star Limited | Wholesale & retail | 2025 |
| Simplesunion Ltd | Manufacturing | 2025 |
| Simplevending Ltd | Wholesale & retail | 2025 |
| Simply Tax Limited | Professional & scientific | 2004 |
| Simpsino Ltd | Construction | 2022 |
| Sina Developments Ltd | Construction | 2024 |
| Singh Realty Ltd | Real estate | 2025 |
| Singhs Portfolio Ltd | Real estate | 2024 |
| Singletree Accountants Ltd | Professional & scientific | 2015 |
| Singletree Advisory Ltd | Financial services | 2024 |
| Singletree Consultancy Ltd | Professional & scientific | 2024 |
| Singletree Foods Ltd | Wholesale & retail | 2024 |
| Singletree Ltd | Financial services | 2020 |
| Singletree Properties Ltd | Real estate | 2024 |
| Singletree Trade Ltd | Wholesale & retail | 2024 |
| Singletree Trading Ltd | Financial services | 2024 |
| SIO Car Ltd | Wholesale & retail | 2025 |
| Sirius Solar Systems Ltd | Extraterritorial | 2011 |
| Sister & Sister Ltd | Health & social care | 2015 |
| Sisters Right Care Ltd | Health & social care | 2020 |
| Sisu Group Ltd | Wholesale & retail | 2022 |
| Sitha Designs Limited | Manufacturing | 2011 |
| Sivagams Academy Ltd | Education | 2015 |
| Sixwestroad Ltd | Real estate | 2018 |
| Siyaram LLP | | 2011 |
| Size Consultancy Ltd. | Wholesale & retail | 2017 |
| SJ Accounting Partners Ltd | Extraterritorial | 2025 |
| SJ Nails Beauty Limited | Other services | 2020 |
| SJ Nails Limited | Other services | 2024 |
| SJ Nexus Ltd | Financial services | 2025 |
| Sjda Group Ltd | Real estate | 2018 |
| Sjda Property Group Ltd | Real estate | 2024 |
| Sjmpf Ltd | Real estate | 2018 |
| SJR Retail (LND) Limited | Wholesale & retail | 2018 |
| SJS Repairs Ltd | Construction | 2018 |
| SK Bright Homes Ltd | Health & social care | 2024 |
| SK Courier Ltd | Transport & logistics | 2015 |
| SK Hire Events Ltd | Other services | 2025 |
| SK Plant Operator Ltd | Administrative & support | 2018 |
| SK Refrigeration & Cooling Limited | Manufacturing | 2024 |
| SK Sheikh Trading Ltd | Professional & scientific | 2020 |
| SK Valkanov Limited | Construction | 2013 |
| Skayla Outdoor Ltd | Construction | 2026 |
| Skilled Logistics Ltd | Transport & logistics | 2025 |
| Skills Cafe Ltd | Education | 2025 |
| Skitz Distribution Ltd | Wholesale & retail | 2024 |
| SKK Electrical Ltd | Construction | 2007 |
| Sknt Ltd | Wholesale & retail | 2026 |
| Skntone Ltd | Wholesale & retail | 2020 |
| Skrannies Ltd | Hospitality | 2020 |
| Sky Eclipse Ltd | Construction | 2025 |
| Sky Facilities Management Group Ltd | Administrative & support | 2014 |
| Sky GOK Property Ltd | Real estate | 2025 |
| Sky High Records Ltd | Information & communication | 2023 |
| Sky Nails & Spa Ltd | Other services | 2019 |
| Sky Photography & Videography Ltd | Information & communication | 2018 |
| Sky Security Ltd | Administrative & support | 2023 |
| Sky-Home LP | | 2014 |
| Skyline-Investing Limited | Real estate | 2025 |
| SL Electronic Specialists Ltd | Wholesale & retail | 2024 |
| Slavi Hands Ltd | Construction | 2025 |
| SLG X Hire Ltd | Transport & logistics | 2020 |
| Slice of Kebab Ltd | Hospitality | 2026 |
| Slidesymphony Ltd | Information & communication | 2023 |
| SM Chinese Limited | Hospitality | 2023 |
| SM Construction & Maintenance Ltd | Construction | 2021 |
| SM Decorators London Ltd | Construction | 2022 |
| SM Drylining Solutions Ltd | Construction | 2024 |
| SM Properties Solutions Ltd | Real estate | 2023 |
| SM Tutors Limited | Education | 2025 |
| Sm&A Cleaning Service Limited | Administrative & support | 2025 |
| Small Comforts Ltd | Wholesale & retail | 2020 |