| Sirmcon Limited | Construction | 2018 |
| Sirosh & Behraam Food Ltd | Hospitality | 2023 |
| SIS Coatings Ltd | Construction | 2015 |
| SIS Community Life Ltd | Health & social care | 2018 |
| Sisbanco Limited | Hospitality | 2015 |
| Sister Sphere Ltd | Health & social care | 2025 |
| Sisters United CIC | Arts & recreation | 2024 |
| Sistren Ltd | Financial services | 2022 |
| Sita Nivas Ltd | Real estate | 2017 |
| Site Crew Connect Ltd | Construction | 2025 |
| Site Specialist Services Design and Build Limited | Professional & scientific | 2012 |
| Sitenet Tech Ltd | Information & communication | 2020 |
| Siteup Ltd | Construction | 2025 |
| Sitro Ltd | Financial services | 2019 |
| SIU Construct Ltd | Construction | 2019 |
| Siva Consulting Limited | Real estate | 2026 |
| Siva Shankaram Ltd | Real estate | 2020 |
| Siva Smiles Ltd | Health & social care | 2022 |
| Sivada Residential Limited | Real estate | 2021 |
| Sivakumaran Ltd | Real estate | 2025 |
| Sivas Choice Ltd | Wholesale & retail | 2025 |
| Sivean Limited | Administrative & support | 2021 |
| Sivi Properties (London) Ltd | Real estate | 2023 |
| Sivia Sons Ltd | Wholesale & retail | 2024 |
| SIX Alchemy Limited | Wholesale & retail | 2024 |
| SIX Seven Capital Investment Ltd | Other services | 2017 |
| SIX Sixes Ltd | Real estate | 2025 |
| SIX Spoons Ltd | Hospitality | 2025 |
| Sixty Four One Consulting Limited | Information & communication | 2021 |
| Sixty Four One Limited | Professional & scientific | 2009 |
| Siyat Limited | Construction | 2025 |
| SIZ Solutions Limited | Transport & logistics | 2017 |
| Sizas Ltd | Professional & scientific | 2025 |
| Sizmete Ltd | Transport & logistics | 2018 |
| SJ Eyecare Ltd | Health & social care | 2025 |
| SJ Global Investments Limited | Real estate | 2013 |
| SJ Home Design Ltd | Construction | 2019 |
| SJ Personnel Ltd | Administrative & support | 2021 |
| SJ Protect Windows Limited | Construction | 2026 |
| SJ Realtor Properties Ltd | Real estate | 2025 |
| SJ Reporting Ltd | Health & social care | 2014 |
| SJA Electrical Ltd | Construction | 2025 |
| SJH Pharma Limited | Wholesale & retail | 2020 |
| SJI Estates Ltd | Real estate | 2025 |
| SJM Productions Limited | Information & communication | 2014 |
| Sjvb Services Limited | Construction | 2013 |
| SJW Grace Holdings Limited | Real estate | 2026 |
| SK 101 Ltd | Real estate | 2025 |
| SK Accountants and Tax Consultants Ltd | Professional & scientific | 2015 |
| SK Appworks Ltd | Information & communication | 2026 |
| SK Convenience Limited | Wholesale & retail | 2019 |
| SK Design and Construct Ltd | Construction | 2025 |
| SK Diabetes Services Limited | Health & social care | 2013 |
| SK Double Glazing Ltd | Construction | 2014 |
| SK Elevate Ltd | Construction | 2026 |
| SK Esthetique Ltd | Other services | 2025 |
| SK Facilities Ltd | Administrative & support | 2025 |
| SK Family Homes Ltd | Real estate | 2024 |
| SK Family Law Ltd | Professional & scientific | 2023 |
| SK Global Commerce Ltd | Information & communication | 2025 |
| SK Global Services Ltd | Wholesale & retail | 2025 |
| SK Hamilton Holdings Ltd | Real estate | 2025 |
| SK Hotak Ltd | Wholesale & retail | 2026 |
| SK Intelligent Solutions Limited | Information & communication | 2012 |
| SK Khatun Limited | Administrative & support | 2024 |
| SK London Adviser Ltd | Professional & scientific | 2026 |
| SK Management Group Limited | Wholesale & retail | 2025 |
| SK MOT Testing Centre Limited | Wholesale & retail | 2017 |
| SK Properties London Ltd | Real estate | 2017 |
| SK Radiology Services Ltd | Health & social care | 2017 |
| SK Shop Online Limited | Wholesale & retail | 2023 |
| SK Taba Limited | Other services | 2024 |
| SK Takeaway Limited | Hospitality | 2025 |
| SK Vision Ltd | Hospitality | 2017 |
| SK102 Ltd | Real estate | 2025 |
| SK25 Trading Co Limited | Wholesale & retail | 2025 |
| SK9 Securtiy Ltd | Administrative & support | 2025 |
| Skadj Ltd | Health & social care | 2014 |
| Skanda Developments Ltd | Real estate | 2023 |
| Skanda Global Limited | Professional & scientific | 2016 |
| Skanda Properties Ltd | Real estate | 2021 |
| Skanda Protect Ltd | Professional & scientific | 2020 |
| Skanda Solutions PVT Limited | Information & communication | 2015 |
| Skandapro Solutions PVT Limited | Information & communication | 2018 |
| Skandi Eira Limited | Wholesale & retail | 2025 |
| Skate WIT Spirit Limited | Education | 2025 |
| SKB Property Services Ltd | Real estate | 2024 |
| SKC Capital Limited | Administrative & support | 2000 |
| SKC Finance Limited | Financial services | 1988 |
| SKC Group Limited | Administrative & support | 1996 |
| SKC Hotels Limited | Hospitality | 1993 |
| SKC Leisure Limited | Construction | 1994 |
| Skch Limited | Construction | 2026 |
| Skdar Ltd | Wholesale & retail | 2023 |
| Skey Mobile Ltd | Wholesale & retail | 2018 |
| SKF Global Education Ltd | Education | 2025 |
| Skhk Properties Ltd | Real estate | 2018 |
| Skill & Scale Ltd | Wholesale & retail | 2025 |
| Skilldots Limited | Education | 2020 |
| Skilled Academy Ltd | Education | 2025 |