| Seriously Clever Productions Limited | Information & communication | 2023 |
| Serowalia Properties Limited | Real estate | 2022 |
| Seru Services Ltd | Hospitality | 2023 |
| SET OUT Ltd | Manufacturing | 2022 |
| SET Square Construction Ltd | Construction | 2024 |
| Setynia Ltd | Wholesale & retail | 2022 |
| Sevani Legal Services Ltd | Professional & scientific | 2023 |
| Sewak Properties Limited | Real estate | 2019 |
| Seyeama Limited | Construction | 2019 |
| Seygre Property Limited | Real estate | 2021 |
| SG Dopahive Ltd | Hospitality | 2025 |
| SH Lactation Consultant Ltd | Public administration | 2025 |
| SH Property Consultancy Limited | Real estate | 2024 |
| Shaaa Transport Ltd | Wholesale & retail | 2022 |
| Shabo Investments Ltd | Real estate | 2024 |
| Shade and Shield UK Limited | Wholesale & retail | 2019 |
| Shah and Brothers Ltd | Wholesale & retail | 2024 |
| Shah Properties & Investments Limited | Real estate | 2017 |
| Shahzad Raja Limited | Health & social care | 2015 |
| Shail Vasa Production Limited | Information & communication | 2024 |
| Shaken by Limited | Hospitality | 2026 |
| Shalluz Ltd | Wholesale & retail | 2024 |
| Sham Property Management Ltd | Households | 2018 |
| Sham Village Ltd | Wholesale & retail | 2020 |
| Shama Pharma Ltd | Manufacturing | 2017 |
| Shamloo Foreign Exchange Ltd | Financial services | 2019 |
| Shams Global Group Limited | Wholesale & retail | 2024 |
| Shanela Limited | Professional & scientific | 2003 |
| Sharika Engineers Limited | Professional & scientific | 2013 |
| Sharley Uniform Ltd | Wholesale & retail | 2019 |
| Sharyo Ltd | Other services | 2024 |
| Shayona Business Services Limited | Professional & scientific | 2009 |
| Shazil Sherazi Limited | Administrative & support | 2026 |
| Shebahl Skills & Support Services Ltd | Education | 2010 |
| Sheen Car Hire Ltd | Transport & logistics | 2023 |
| Shehabi Limited | Financial services | 2020 |
| Sheikhlal Foundation | Health & social care | 2023 |
| Shenena Sethi Ltd | Wholesale & retail | 2017 |
| Shepherd & Edwards Properties Limited | Real estate | 2017 |
| Shepose Limited | Wholesale & retail | 2024 |
| Sher Estates Ltd | Real estate | 2025 |
| Sher Property Developments Ltd | Construction | 2025 |
| Shergar Limited | Real estate | 2018 |
| Sheridans Galway Groundworks Limited | Construction | 2014 |
| Sherrys Wholesale Limited | Wholesale & retail | 2007 |
| Sheryl Ellis Creative Ltd | Professional & scientific | 2019 |
| SHH Property Investments Limited | Financial services | 2022 |
| Shine Factory Ltd | Wholesale & retail | 2021 |
| Shiny Toy Guns Ltd | Information & communication | 2026 |
| Shiptrends Store Ltd | Wholesale & retail | 2020 |
| Shiraz & SON Investments Limited | Real estate | 2025 |
| Shiva Consultancy Limited | Professional & scientific | 2009 |
| Shivay Gems and Jawels Limited | Manufacturing | 2026 |
| Shivay Global Ltd | Wholesale & retail | 2025 |
| SHK Brothers Ltd | Financial services | 2021 |
| SHN London Limited | Professional & scientific | 2018 |
| SHO Construction Limited | Construction | 2020 |
| Sholepace Limited | Professional & scientific | 1983 |
| Shonin Ltd | Wholesale & retail | 2025 |
| Shop-Cheap&Co Ltd | Wholesale & retail | 2023 |
| Shopytrend Limited | Wholesale & retail | 2025 |
| Showroom Utopia LDN Limited | Wholesale & retail | 2023 |
| Shree Associates Limited | Administrative & support | 2009 |
| Shree Balaji Sweets and Savoury Ltd | Hospitality | 2024 |
| Shri Anandam Arts Ltd | Arts & recreation | 2025 |
| Shubh Services Ltd | Administrative & support | 2020 |
| Shukri Ahmed Ltd | Administrative & support | 2021 |
| Shyraj Ltd | Administrative & support | 2025 |
| Sianymac Limited | Other services | 2013 |
| Siblinc Productions Limited | Information & communication | 2022 |
| SID Constructions Limited | Construction | 2007 |
| Siddh Estates Limited | Real estate | 2023 |
| Siemienczuk Estates Limited | Real estate | 2026 |
| Sigma LND Ltd | Wholesale & retail | 2021 |
| Sigmaplus Trading Ltd | Wholesale & retail | 2022 |
| Silesia Homes Ltd | Construction | 2017 |
| Silk Media Ltd | Information & communication | 2019 |
| Silk Route Cafe Limited | Hospitality | 2019 |
| Silnat Holdings Limited | Financial services | 2014 |
| Silver Box Limited | Information & communication | 1991 |
| Silverlock Management Resources Limited | Wholesale & retail | 2026 |
| Silveroak Legal Limited | Professional & scientific | 2017 |
| Silveroak Solicitors Limited | Professional & scientific | 2017 |
| Silverson Japan Limited | Professional & scientific | 2011 |
| Silverson Machines Holdings Limited | Financial services | 2014 |
| Silverson Machines Limited | Manufacturing | 1946 |
| Silvija Ltd | Health & social care | 2018 |
| Simbard Limited | Administrative & support | 2024 |
| Simon's Mango Tree Ltd | Health & social care | 2012 |
| Simonian Group Ltd | Construction | 2023 |
| Simple Account Hub Ltd | Administrative & support | 2024 |
| Simple Property Services Ltd | Real estate | 2024 |
| Simpliflo Ltd | Information & communication | 2025 |
| Simply Shawarma Ltd | Hospitality | 2021 |
| Singh Group Builders Ltd | Construction | 2024 |
| Singh Sahib Construction Limited | Construction | 2024 |
| Singh UK Investment Ltd | Real estate | 2022 |
| Sinla Limited | Construction | 2011 |
| Sippar Lounge Limited | Hospitality | 2019 |
| Sirius Wise Ltd | Wholesale & retail | 2022 |