| SEE IT Clean Ltd | Administrative & support | 2021 |
| Seenu Tech Solutions Limited | Information & communication | 2023 |
| Seinia Ltd | Transport & logistics | 2019 |
| SEJ Consultancy Ltd | Information & communication | 2021 |
| Selabs Ltd | Information & communication | 2015 |
| Selectnest Ltd | Wholesale & retail | 2025 |
| Selfofix (Agricultural Industrial Casting) Limited | | 1977 |
| Selgave Ltd | Real estate | 2015 |
| Semayo Ltd | Wholesale & retail | 2026 |
| Semtronics Limited | Professional & scientific | 2015 |
| SEN8 Property Management Ltd | Real estate | 2025 |
| Senator Sales Limited | Financial services | 2011 |
| Senbazuru Therapies Limited | Health & social care | 2019 |
| Sengupta Enterprise Ltd | Professional & scientific | 2018 |
| Sensate Digital Ltd | Information & communication | 2019 |
| Sensmni Solutions (Smc-Pvt) Ltd | Information & communication | 2025 |
| Senti MCS Ltd | Information & communication | 2024 |
| Senturon Group Ltd | Administrative & support | 2025 |
| Senturon Solutions Ltd | Professional & scientific | 2026 |
| SEO and Content Solutions Limited | Information & communication | 2024 |
| Seoul to London Beauty Ltd | Wholesale & retail | 2025 |
| Septentriones Limited | Hospitality | 2011 |
| Serein Aesthetics Ltd | Health & social care | 2026 |
| Serendipity Business Solutions Ltd | Professional & scientific | 2004 |
| Serene Homecare Services Ltd | Health & social care | 2024 |
| Serene Homeopathy Ltd | Health & social care | 2022 |
| Serenity Accountants Ltd | Professional & scientific | 2019 |
| Serenity K Limited | Other services | 2019 |
| Serenity Wellbeing Limited | Health & social care | 2014 |
| Sergio Tacchini Europe Limited | Wholesale & retail | 2021 |
| Serious Lights Limited | Extraterritorial | 2024 |
| Serious Readers Ltd | Extraterritorial | 2005 |
| Serlux Developments Ltd | Construction | 2025 |
| Servetech Ireland Limited | Construction | 2024 |
| Service Economics Limited | Information & communication | 2024 |
| Setai Ltd | Wholesale & retail | 2015 |
| Setam Ltd | Other services | 2025 |
| Sethara's Limited | Households | 2020 |
| Seven Athlete Management Limited | Professional & scientific | 2020 |
| Seven Beat Media Limited | Professional & scientific | 2024 |
| Seven Lands Farm Ltd | Agriculture & fishing | 2015 |
| Sevenfold Services Limited | Transport & logistics | 2023 |
| Sevnaski Limited | Hospitality | 2022 |
| Seymour Building Company Limited | Construction | 2013 |
| Seymour House Sills Yard Management Company Ltd | Households | 2021 |
| SF10PROPERTIES Ltd | Real estate | 2024 |
| SFB Care Limited | Health & social care | 2019 |
| SFC Aylesbury Ltd | Hospitality | 2025 |
| SFC Kitchen Limited | Hospitality | 2026 |
| SFE Interiors Ltd | Construction | 2025 |
| Shades of Beauty Ltd | Other services | 2025 |
| SHADES66 Limited | Professional & scientific | 2024 |
| Shaikai Properties Limited | Real estate | 2024 |
| Shair Innovation Limited | Information & communication | 2020 |
| Shake Mania Limited | Hospitality | 2021 |
| Shalati Limited | Health & social care | 2016 |
| Shane Phipps Carpentry Ltd | Construction | 2021 |
| Shangrila Investments Limited | Real estate | 2022 |
| Shantabishnu Limited | Real estate | 2025 |
| Shape Bucks Limited | Health & social care | 1990 |
| Shard Tech Limited | Information & communication | 2015 |
| Shard Tech Software Ltd | Information & communication | 2024 |
| Share the Seat Ltd | Wholesale & retail | 2024 |
| Shared Creative Limited | Information & communication | 2026 |
| Sharkeys Bar and Restaurant Ltd | Hospitality | 2026 |
| Sharky's Scents Limited | Wholesale & retail | 2018 |
| Sharp Fencing Limited | Construction | 2003 |
| Shashi Dias Ltd | Health & social care | 2013 |
| Shaw D Limited | Financial services | 2024 |
| Shaw Dentistry Limited | Health & social care | 2021 |
| Shawn Packaging Limited | Manufacturing | 2023 |
| Shaws Plumbing and Heating Limited | Construction | 2010 |
| Shazi Holdings Ltd | Information & communication | 2024 |
| SHE I Y Limited | Construction | 2007 |
| SHEBAKES316 Ltd | Manufacturing | 2024 |
| Sheepskin Wholesale Limited | Wholesale & retail | 2020 |
| Shelby Estates Ltd | Real estate | 2015 |
| Shelley Hansen Limited | Wholesale & retail | 2016 |
| Shelmedics Ltd | Health & social care | 2021 |
| Shennans Holdings Limited | Extraterritorial | 2016 |
| Shennans Limited | Extraterritorial | 2016 |
| Shennans Property Limited | Real estate | 2016 |
| Shennans Ventures Limited | Financial services | 2013 |
| Sherbaz United Ltd | Real estate | 2025 |
| Sherlocks Consulting Limited | Professional & scientific | 2008 |
| Shield Maintenance Limited | Administrative & support | 2005 |
| Shield Office Interiors Limited | Wholesale & retail | 2001 |
| Shift Car Solutions Limited | Information & communication | 2025 |
| Shimmer UK Bidco Limited | Financial services | 2022 |
| Shine Autos Ltd | Wholesale & retail | 2024 |
| Shining Cristal Ltd | Administrative & support | 2025 |
| Shipka Ltd | Information & communication | 2013 |
| Shipton LEE Property Ltd | Construction | 2026 |
| Shiptraco Ltd | Transport & logistics | 2021 |
| Shirley Parsons Holdings Limited | Financial services | 2021 |
| Shirley Parsons Limited | Professional & scientific | 2005 |
| Shirley Parsons Professional Services Limited | Professional & scientific | 2003 |
| Shirley Parsons Project Services Limited | Professional & scientific | 2019 |
| Shiron Financial Solutions Limited | Professional & scientific | 2013 |
| Shivapriya Estates Ltd | Real estate | 2024 |