| Simrans Services Limited | Information & communication | 2004 |
| Simrat Limited | Real estate | 2020 |
| Simsim Property Ltd | Real estate | 2023 |
| Simtra Capital Ltd | Real estate | 2018 |
| Simz Homes Ltd | Real estate | 2025 |
| Sincerely Homes C.I.C. | Hospitality | 2024 |
| Sinclair Automotive Ltd | Wholesale & retail | 2023 |
| SING4YOU Limited | Arts & recreation | 2021 |
| Singara Ltd | Information & communication | 2016 |
| Singh Accessories Ltd | Administrative & support | 2016 |
| Singh Digging Ltd | Construction | 2019 |
| Singh Digging Services Ltd | Construction | 2018 |
| Singh Express Ltd | Transport & logistics | 2022 |
| Singh G Builder Ltd | Construction | 2023 |
| Singh Investment Management Ltd | Extraterritorial | 2017 |
| Singh Pharma PVT Limited | Wholesale & retail | 2026 |
| Singh Roadlines Limited | Transport & logistics | 2019 |
| Singh's PVT Limited | Other services | 2023 |
| SINGH96 Construction Ltd | Construction | 2024 |
| Singhs Transportion Ltd | Transport & logistics | 2026 |
| Singhz Ltd | Transport & logistics | 2024 |
| Single Muslims Marriage Events Limited | Other services | 2018 |
| Sinna Investments Ltd | Real estate | 2021 |
| Sinna JH Limited | Administrative & support | 2021 |
| Sinova Estates Limited | Real estate | 2024 |
| SIO Consultancy Ltd | Professional & scientific | 2017 |
| SIQ Properties Limited | Real estate | 2020 |
| Sira 1 Ltd | Wholesale & retail | 2025 |
| Siraco Ltd | Wholesale & retail | 2018 |
| Sirah Tours Ltd | Administrative & support | 2025 |
| Sird Properties Limited | Real estate | 2022 |
| Sird Technologies Limited | Information & communication | 2020 |
| Siri Foods Ltd | Wholesale & retail | 2025 |
| Siriforge Co-Intelligence Ltd | Information & communication | 2026 |
| Sirocco Enterprise Ltd | Real estate | 2015 |
| Sisma Care Ltd | Health & social care | 2025 |
| Sisma Developments Limited | Construction | 2015 |
| Sisterhood Community CIC | Education | 2025 |
| Sitcon Consulting Services Private Limited | Information & communication | 2024 |
| Sitcon Ltd | Information & communication | 2024 |
| Site Cleaning Services Limited | Real estate | 2025 |
| Site FIX Solution Ltd | Construction | 2023 |
| Site Wrapp Limited | Wholesale & retail | 2014 |
| Sitewatchuk.Com Ltd | Administrative & support | 2014 |
| Sixt Limited | Extraterritorial | 1997 |
| Sixt Rent a Car Limited | Administrative & support | 1947 |
| Sixth Key Property Ltd | Real estate | 2026 |
| Sixth Rochford (Slough) Management Company Limited | Households | 1981 |
| Sixth Sense Production Ltd | Information & communication | 2026 |
| Sixty Three Investments Limited | Real estate | 2018 |
| SIY Limited | Hospitality | 2025 |
| SIY Slough Ltd | Hospitality | 2026 |
| Siya Lettings Ltd | Real estate | 2021 |
| Siyaa Investments Limited | Real estate | 2025 |
| SJB Bains Limited | Real estate | 2024 |
| SJB Healthcare Services Ltd | Health & social care | 2021 |
| SJF Imperium Construction & Engineering Limited | Construction | 2024 |
| SJH Air Conditioning Ltd | Energy | 2016 |
| SJM Realty Ltd | Real estate | 2024 |
| Sjmco Ltd | Construction | 2023 |
| Sjrin Ltd | Construction | 2024 |
| SJS Rams Ltd | Manufacturing | 2018 |
| Sjtl Services Limited | Construction | 2019 |
| SK & Co. Investments Limited | Construction | 2019 |
| SK & HR Ltd | Wholesale & retail | 2024 |
| SK & Sons Ltd | Real estate | 2023 |
| SK 67 Ltd | Construction | 2013 |
| SK AV Limited | Information & communication | 2022 |
| SK Beauty & Aesthetics Ltd | Other services | 2023 |
| SK Cash & Carry 07 Ltd | Wholesale & retail | 2026 |
| SK Construction (London) Limited | Construction | 2011 |
| SK CONSTRUCTION1 Ltd | Construction | 2023 |
| SK Croydon Limited | Construction | 2023 |
| SK Data Solutions Ltd | Information & communication | 2024 |
| SK Developco Limited | Construction | 2025 |
| SK Distribution Limited | Transport & logistics | 2008 |
| SK Fadez & Cutz Ltd | Other services | 2020 |
| SK Global Mart Ltd | Wholesale & retail | 2025 |
| SK Green Ltd | Construction | 2025 |
| SK Group Ltd | Hospitality | 2026 |
| SK Groupco Limited | Financial services | 2025 |
| SK Logistics & Transport Ltd | Transport & logistics | 2025 |
| SK Mini Market Ltd | Wholesale & retail | 2025 |
| SK Multani Transport Ltd | Transport & logistics | 2023 |
| SK Network Services Ltd | Information & communication | 2011 |
| SK Trading Co Ltd | Wholesale & retail | 2023 |
| SK5 Textiles Ltd | Wholesale & retail | 2023 |
| SKA Financial Services Ltd | Professional & scientific | 2011 |
| SKA Property Investment Limited | Real estate | 2018 |
| Skan Investment Limited | Real estate | 2022 |
| Skang Holding Ltd | Real estate | 2026 |
| Skartis Ltd | Construction | 2019 |
| Skata Limited | Wholesale & retail | 2018 |
| Skavent Ltd | Wholesale & retail | 2022 |
| SKB Investments Ltd | Real estate | 2016 |
| SKB Recruitment Ltd | Administrative & support | 2025 |
| SKE Leather Limited | Wholesale & retail | 2026 |
| SKE Technologies Limited | Information & communication | 2023 |
| SKH Group (UK) Limited | Professional & scientific | 2013 |
| SKH Surveying Ltd | Real estate | 2021 |