| Shuvra’S Academy Ltd | Education | 2026 |
| Shwaz Limited | Construction | 2022 |
| Shyamaa Limited | Real estate | 2023 |
| Shyamaa Living Ltd | Wholesale & retail | 2025 |
| Shyfa Ltd | Public administration | 2024 |
| SI Investment Group Ltd | Real estate | 2017 |
| SI Property & Management Ltd | Real estate | 2019 |
| SI Shelters Ltd | Hospitality | 2024 |
| SI Tyres & Vehicle Recovery Services Ltd | Wholesale & retail | 2019 |
| SIA Transport Ltd | Transport & logistics | 2016 |
| Sial Capital Ltd | Professional & scientific | 2026 |
| Sial Group Ltd | Households | 2019 |
| Sialkoti Builders Ltd | Construction | 2026 |
| Siam Partnership Ltd | Real estate | 2025 |
| Sibitaz Limited | Manufacturing | 2010 |
| Sibjoya Builders Limited | Construction | 2025 |
| Sibling Scents Ltd | Manufacturing | 2023 |
| Sibyos Enterprises Limited | Wholesale & retail | 2026 |
| Sibyos Trading Limited | Wholesale & retail | 2025 |
| Siconda Trading Limited | Other services | 2022 |
| SID Technology Limited | Other services | 2019 |
| Sid&Cia Ltd | Construction | 2017 |
| Siddhi Investments Ltd | Real estate | 2018 |
| Siddiqi Properties Ltd | Real estate | 2018 |
| Siddique Consultants Limited | Construction | 2014 |
| Siddiqui & Co Limited | Professional & scientific | 2005 |
| Siddiqui Pharma Ltd | Wholesale & retail | 2023 |
| Sideal Shopfront and Shutters Ltd | Construction | 2025 |
| Sideal Shutters Experts Ltd | Construction | 2025 |
| Sidegate Limited | Real estate | 2006 |
| Sidhu Construction (U.K.) Ltd | Construction | 2023 |
| Sidhu Jatt Ltd | Real estate | 2026 |
| Sidhu Roofing Ilford Limited | Construction | 2024 |
| Sidloff Associates Limited | Health & social care | 2014 |
| Sidma Shiv Ltd | Hospitality | 2025 |
| Sienna & Reece Property Co Ltd | Real estate | 2025 |
| Siera Consultancy Ltd | Information & communication | 2018 |
| SIERRA4 Limited | Wholesale & retail | 2025 |
| Sifat Development Ltd | Real estate | 2023 |
| Sifra Food Ltd | Hospitality | 2025 |
| Sify Technology PTE Limited | Manufacturing | 2024 |
| SIG Plastering Ltd | Construction | 2017 |
| Sightskaters Ltd | Health & social care | 2025 |
| Sigis Services Limited | Construction | 2007 |
| Sigma CAB Rental Ltd | Transport & logistics | 2021 |
| Sigma Construction Group Ltd | Construction | 2025 |
| Sigma Construction Services UK Ltd | Construction | 2024 |
| Sigma Corporate Services Limited | Professional & scientific | 2018 |
| Sigma Gadgets Ltd | Wholesale & retail | 2025 |
| Sigma Implants Ltd | Wholesale & retail | 2012 |
| Sigma Realty Ltd | Other services | 2013 |
| Sigma Services (Home Counties) Ltd | Construction | 2002 |
| Sign O Graphics Ltd | Wholesale & retail | 2011 |
| Sign O Print Ltd | Professional & scientific | 2022 |
| Signage Designs Ltd | Manufacturing | 2025 |
| Signati Signa Limited | Construction | 2023 |
| Signature Building and Construction Limited | Construction | 2025 |
| Signature by Anam Ltd | Wholesale & retail | 2025 |
| Signature Construction London Limited | Construction | 2018 |
| Signature Foods Limited | Hospitality | 2012 |
| Signature Homes London Ltd | Real estate | 2023 |
| Signature Hotel London Ltd | Hospitality | 2014 |
| Signet Standard Ltd | Financial services | 2023 |
| Signman Says Ltd | Education | 2024 |
| Signor Design Limited | Professional & scientific | 2015 |
| Signs DE Art Ltd | Construction | 2023 |
| Signway Limited | Administrative & support | 2000 |
| Sihag Bros Logistics Ltd | Transport & logistics | 2026 |
| Sijo Limited | Health & social care | 2022 |
| Sikder Care Limited | Health & social care | 2022 |
| Sikder Properties Development Ltd | Construction | 2025 |
| Sikder Properties Limited | Real estate | 2022 |
| Silent Knight Plumbing & Heating Ltd | Manufacturing | 2023 |
| Silent Temple Films Ltd | Information & communication | 2016 |
| Silistra Retail Business Ltd | Wholesale & retail | 2024 |
| Silk Beauty Collective Ltd | Wholesale & retail | 2026 |
| Silk District Properties Limited | Real estate | 2018 |
| Silk Kitchen Ltd | Hospitality | 2025 |
| Silk Plaza Limited | Real estate | 2018 |
| Silk Road Supplements Limited | Hospitality | 2023 |
| Silkacore Ltd | Information & communication | 2025 |
| Silkoak Global Limited | Wholesale & retail | 2016 |
| Silkroute Construction Limited | Construction | 2025 |
| Silu's Yummy Yard Limited | Manufacturing | 2025 |
| Silver Built Properties Limited | Real estate | 2020 |
| Silver Burst Limited | Real estate | 2018 |
| Silver Clay Limited | Other services | 2020 |
| Silver Hyacinth Limited | Wholesale & retail | 2024 |
| Silver Lining Care Group Ltd | Health & social care | 2025 |
| Silver Phoenix 84 Ltd | Real estate | 2020 |
| Silver Platter Cutlery Limited | Hospitality | 2026 |
| Silvercrest 1 Ltd | Wholesale & retail | 2026 |
| Silvercroft Grove Limited | Construction | 2020 |
| Silverhawk Ventures Ltd | Professional & scientific | 2024 |
| Silverkey Properties Inc Limited | Construction | 2025 |
| Silverleafcare Ltd | Health & social care | 2025 |
| Silverline Outlet Limited | Wholesale & retail | 2016 |
| Silverlink Estate Ltd | Real estate | 2021 |
| Silverlink Holdings Limited | Financial services | 2026 |
| Silverlink Management Limited | Real estate | 2022 |