| Shri Krishna Pranami UK Limited | Other services | 2018 |
| Shri Nagin Properties Ltd | Real estate | 2018 |
| Shri Naginbhai (UK) Limited | Wholesale & retail | 2003 |
| Shri S & R Properties Ltd | Real estate | 2017 |
| Shriji Consultancy Limited | Information & communication | 2019 |
| Shriji Consultants Ltd | Information & communication | 2013 |
| Shriji Kripa Properties Limited | Professional & scientific | 2019 |
| Shriji Realty Ltd | Real estate | 2021 |
| Shriyan Trends Limited | Wholesale & retail | 2026 |
| SHS Consultancy (UK) Ltd | Information & communication | 2011 |
| SHU JUN Ltd | Health & social care | 2008 |
| Shuhrat Abdulloev Limited | Construction | 2021 |
| Siam Noodles Ltd | Hospitality | 2022 |
| Sibo Limited | Real estate | 2022 |
| Siddh Properties Ltd | Real estate | 2023 |
| Siddheshwar Ltd | Wholesale & retail | 2025 |
| Sieley Property Limited | Real estate | 2017 |
| Sienna Propco Limited | Real estate | 2023 |
| Sifi Homes Ltd | Real estate | 2024 |
| Sifmere Limited | Professional & scientific | 2025 |
| Sifmon Limited | Professional & scientific | 2026 |
| SIG Capital Limited | Real estate | 2019 |
| Sigma Protection Ltd | Administrative & support | 2024 |
| Sigma Star Carpentry Ltd | Construction | 2019 |
| Signature Manors Limited | Real estate | 2024 |
| Signature Persian Restaurant Ltd | Hospitality | 2025 |
| Signmi AI Ltd | Information & communication | 2025 |
| Signpost Properties Limited | Extraterritorial | 1962 |
| Sigona Property Limited | Real estate | 2021 |
| Sijesrie Care Providers Ltd | Health & social care | 2025 |
| Sikk Properties Ltd | Real estate | 2023 |
| Silbia Ltd | Transport & logistics | 2015 |
| Sile Construction Services Ltd | Construction | 2021 |
| Silemon Limited | Professional & scientific | 2022 |
| Silk Metro Ltd | Wholesale & retail | 2025 |
| Silk Road Suppliers Ltd | Wholesale & retail | 2019 |
| Silva Business Ltd | Hospitality | 2026 |
| Silva Psychology Limited | Education | 2011 |
| Silvanus Education Ltd | Health & social care | 2022 |
| Silvatur Ltd | Administrative & support | 2024 |
| Silver Distribution Ltd | Wholesale & retail | 2022 |
| Silver Link Trading Ltd | Wholesale & retail | 2019 |
| Silver New Grey Limited | Arts & recreation | 2024 |
| Silverage Homes Limited | Real estate | 2024 |
| Silverback Grips Limited | Information & communication | 2007 |
| Silverbrook Limited | Real estate | 2024 |
| Silverlinx Ltd | Transport & logistics | 2014 |
| Silvermans AP Limited | Professional & scientific | 2006 |
| Silveroak Northwest Ltd | Real estate | 2026 |
| Silverstone Car Center Ltd | Wholesale & retail | 2025 |
| Silviesta Solutions Limited | Information & communication | 2016 |
| SIM Locum Limited | Professional & scientific | 2011 |
| Simbano LLP | | 2026 |
| Simbury Limited | Professional & scientific | 2025 |
| Simchah Investments Limited | Real estate | 2018 |
| Simdent Dental Care Limited | Health & social care | 2011 |
| Similis Pharma Limited | Wholesale & retail | 2024 |
| Simms Capital Group Limited | Financial services | 2024 |
| Simo Service Solutions Limited | Information & communication | 2024 |
| Simon Blackwell Limited | Arts & recreation | 2005 |
| Simon Bloom Consultancy Limited | Professional & scientific | 2012 |
| Simon Medical Services Limited | Health & social care | 2013 |
| Simon Pinkus Ltd | Information & communication | 2024 |
| Simon Plumbing Ltd | Construction | 2026 |
| Simon Symeou SMP Ltd | Other services | 2016 |
| Simple Delivery Ltd | Transport & logistics | 2018 |
| Simple Fast Food Ltd | Hospitality | 2012 |
| Simple Solutions (Edgware) Ltd | Professional & scientific | 2012 |
| Simply BIM Limited | Professional & scientific | 2020 |
| Simply Sales Limited | | 2010 |
| Simply Seminars Limited | Professional & scientific | 2013 |
| Simply Sold Limited | Wholesale & retail | 2006 |
| Sinapine Limited | Professional & scientific | 2015 |
| Sinapsis Ltd | Professional & scientific | 2011 |
| Sinclair Builders Limited | Construction | 2016 |
| Sindoor Ltd | Wholesale & retail | 2025 |
| Singing Bowl Meditation Hub Ltd | Wholesale & retail | 2019 |
| Sinlar Limited | Professional & scientific | 2025 |
| Sinna Limited | Hospitality | 2017 |
| Sinpar Limited | Professional & scientific | 2025 |
| SIP & SEW Limited | Arts & recreation | 2024 |
| SIP Store Europe Limited | Wholesale & retail | 2026 |
| Sirer (Cambridge) Property Limited | Real estate | 2015 |
| Sirer Associates Limited | Construction | 2014 |
| Sirer Global Investments Limited | Administrative & support | 2013 |
| Sirer Investments Limited | Real estate | 1995 |
| Sirer Premier Properties Limited | Construction | 2022 |
| Sirer Property Eastbourne Limited | Construction | 2015 |
| Sirume Ltd | Hospitality | 2025 |
| Sisman Investments Limited | Real estate | 2017 |
| Sisol Construction Ltd | Construction | 2025 |
| Sister's Bridal Ltd | Wholesale & retail | 2023 |
| Sisters' Fellowship International | Other services | 2019 |
| Sivam Ltd | Hospitality | 2020 |
| Siviar Limited | Real estate | 2016 |
| Sivtrading Ltd | Wholesale & retail | 2026 |
| SIX Brotherz Ltd | Real estate | 2024 |
| SIX Waves Limited | Wholesale & retail | 2013 |
| Six&One Ltd | Hospitality | 2024 |
| Sixela Limited | Construction | 2018 |