| SD & PK Sharma Investments Ltd | Real estate | 2018 |
| SD Positive Property Investments Ltd | Real estate | 2022 |
| SDS Applications Limited | Information & communication | 1996 |
| SE1 Ltd | Real estate | 2016 |
| Seacole Care Ltd | Health & social care | 2025 |
| Seacole Healthcare Ltd | Health & social care | 2019 |
| Searchfield Developments Limited | Construction | 2012 |
| Searchfield Holdings Ltd | Financial services | 2024 |
| Searchfield Property Group Ltd | Construction | 2022 |
| Seatquota Ltd | Transport & logistics | 2024 |
| Seaview NH Ltd | Health & social care | 2025 |
| Sebastiaan Guzik Properties Ltd | Real estate | 2021 |
| Sebastian & Simon Holding Group Ltd | Administrative & support | 2021 |
| Secluhome Investments Ltd | Real estate | 2021 |
| Secluhome Trading Ltd | Hospitality | 2023 |
| Second Option Ltd | Transport & logistics | 2011 |
| Secure Future Ltd | Other services | 2023 |
| Secure Network and Communications Ltd | Information & communication | 2017 |
| Sedida Properties Ltd | Real estate | 2021 |
| Sedida Real Estate Trading Ltd | Real estate | 2021 |
| SEG Properties Limited | Real estate | 2019 |
| Select Money Management Limited | Financial services | 2020 |
| Self Brothers Limited | Real estate | 2015 |
| Sell IT and Soon Dorset Ltd | Wholesale & retail | 2026 |
| Sell IT and Soon Ltd. | Professional & scientific | 1997 |
| Selling Point Ltd | Wholesale & retail | 2022 |
| Semo Sancus Ltd | Professional & scientific | 2016 |
| Send Adoption Project Community Interest Company | Other services | 2019 |
| Senna Pro 100 Limited | Information & communication | 2023 |
| Sensar Consultancy Ltd | Real estate | 2025 |
| Sertra Limited | Wholesale & retail | 2019 |
| Serviam Management Ltd | Financial services | 2021 |
| Service and Soft Touch Limited | Administrative & support | 2020 |
| Servotest Limited | Administrative & support | 2008 |
| Servotest Systems Ltd | Extraterritorial | 2011 |
| Servotest Testing Systems Ltd | Manufacturing | 2007 |
| SES Technologies UK Limited | Administrative & support | 2013 |
| Sesto Properties Ltd | Real estate | 2020 |
| Setonix Property Investment Ltd | Real estate | 2023 |
| Seubra Limited | Real estate | 2017 |
| SFB Egham Ltd | Hospitality | 2025 |
| SFK Consultants Ltd | Professional & scientific | 2021 |
| SG Madan Properties Limited | Real estate | 2018 |
| SG Properties & Investments Ltd | Real estate | 2021 |
| Shareside-Properties Ltd | Real estate | 2021 |
| Sharkszors Ltd | Manufacturing | 2019 |
| Shawn Shalizi Ltd | Real estate | 2026 |
| Shearn Consulting Ltd | Professional & scientific | 2023 |
| Sheikh Developments Limited | Health & social care | 2012 |
| Shelley Scenery Ltd | Manufacturing | 2021 |
| Shiboom Limited | Administrative & support | 2017 |
| Shield WB Ltd | Real estate | 2015 |
| Shine Real Estate UK Ltd | Real estate | 2025 |
| Shiny Bay Ltd | Wholesale & retail | 2023 |
| Shinyshift Cleaning Ltd | Administrative & support | 2025 |
| Shiwu Ltd | Other services | 2025 |
| Shokos Limited | Other services | 2012 |
| Shoreline Collection Ltd | Hospitality | 2025 |
| Shrika Ltd | Information & communication | 2026 |
| Shrimahakali Enterprises Ltd | Real estate | 2025 |
| Shuttleworth Medical Ltd | Manufacturing | 2007 |
| Sideriver Limited | Real estate | 2022 |
| Sigfra UK Ltd | Real estate | 2024 |
| Siggra UK Limited | Construction | 2022 |
| Sigma Supplements Ltd | Wholesale & retail | 2023 |
| Sigma Tech 360 Ltd | Manufacturing | 2016 |
| Signature Ride Ltd | Transport & logistics | 2023 |
| Siip Ltd | Wholesale & retail | 2025 |
| Sili Boys Ltd | Manufacturing | 2023 |
| Silkmore Ltd | Real estate | 2019 |
| Silver Lining Property Limited | Real estate | 2019 |
| Silver Luxe Limited | Other services | 2024 |
| Silver Mist Limited | Wholesale & retail | 2024 |
| Silver River Real Estate Ltd | Real estate | 2021 |
| Silver Star Leasing Limited | Other services | 2012 |
| Simcorp Holding Ltd | Financial services | 2021 |
| Simcorp Investment Ltd | Real estate | 2020 |
| Simcorp Properties Ltd | Real estate | 2021 |
| Simonatina Medical Services Limited | Extraterritorial | 2010 |
| Simply Industrial Ltd | Real estate | 2024 |
| Simply Residence Ltd | Real estate | 2024 |
| Simply Rooms Ltd | Hospitality | 2024 |
| SIO Property Ltd | Real estate | 2023 |
| Sirius Child FD Ltd | Professional & scientific | 2022 |
| Sirius Harvest Limited | Real estate | 2018 |
| Sirrapa Property Group Ltd | Financial services | 2022 |
| Sisterhood Properties Ltd | Real estate | 2025 |
| Sisters Properties Ltd | Real estate | 2024 |
| Siwin Ltd | Professional & scientific | 2022 |
| Sjaj Property Ltd | Real estate | 2022 |
| SJN Properties Ltd | Real estate | 2016 |
| SK Manchester Ltd | Real estate | 2025 |
| Skills Booster UK Limited | Administrative & support | 2024 |
| Skinny Coffee Club Ltd | Wholesale & retail | 2016 |
| SKN William Ltd | Real estate | 2026 |
| Skylac Limited | Information & communication | 2018 |
| Skylark BED & Breakfast LLP | | 2021 |
| Skylineshift Limited | Other services | 2024 |
| Skypath Air Cargo Limited | Transport & logistics | 2026 |
| Skytip Ltd | Real estate | 2025 |