| Solutions Sector Ltd | Wholesale & retail | 2026 |
| Sonderoid Ltd | Information & communication | 2023 |
| Sonic Boom Logistics Limited | Transport & logistics | 2020 |
| Sonic Delivery Ltd | Transport & logistics | 2021 |
| Sood Logistics Limited | Transport & logistics | 2019 |
| Sophia Tech Ltd | Wholesale & retail | 2017 |
| Soro Enterprise Ltd | Wholesale & retail | 2026 |
| Sorry It's Vintage Ltd | Wholesale & retail | 2019 |
| SOS Assets Ltd | Real estate | 2025 |
| SOU Traders Ltd | Construction | 2025 |
| Soullelle Limited | Wholesale & retail | 2023 |
| Sourcehaven Ltd | Wholesale & retail | 2025 |
| Southdale Construction Limited | Construction | 2016 |
| Soyuz Buildings Ltd | Construction | 2026 |
| SP Real Estate Investment Ltd | Real estate | 2024 |
| Spaceview Ltd | Construction | 2021 |
| SPARK2 Education Ltd | Education | 2018 |
| Sparkadvance Ltd | Information & communication | 2023 |
| SPC UK International Ltd | Wholesale & retail | 2024 |
| Spdp Investments Ltd | Real estate | 2022 |
| Spdp Securities Ltd | Financial services | 2025 |
| Specialist Vehicle Industries Ltd | Wholesale & retail | 2025 |
| Speed Fit Tyres Ltd | Wholesale & retail | 2010 |
| Speediprojects Ltd | Information & communication | 2023 |
| Speediwash Ltd | Administrative & support | 2022 |
| Speedy Handyman Ltd | Construction | 2026 |
| Spelthorne Eagles Basketball Ltd | Education | 2024 |
| Spice Cabinet Limited | Hospitality | 2024 |
| Spice Heritage Ltd | Hospitality | 2025 |
| Spice of India UK T/A Cinnimon Takeaway Limited | Hospitality | 2026 |
| Spicy Bite Southall Ltd | Hospitality | 2026 |
| Spiel Traders Ltd | Wholesale & retail | 2025 |
| Spinix Technologies Ltd | Information & communication | 2024 |
| SPL Services Limited | Transport & logistics | 2007 |
| Splitcab Ltd | Information & communication | 2014 |
| Splunk Services UK Limited | Information & communication | 2011 |
| Spring Corner Business Ltd | Wholesale & retail | 2020 |
| Spring Corner Car Sales Ltd | Wholesale & retail | 2025 |
| Spring Cornor Limited | Wholesale & retail | 2025 |
| Springworks Therapeutics UK Limited | Administrative & support | 2022 |
| Sprint World Ltd | Transport & logistics | 2019 |
| SPS Ashford Ltd | Real estate | 2026 |
| SPS Construction Services Ltd | Construction | 2023 |
| SPS Design & Build Ltd | Construction | 2016 |
| SPT (LHR) Limited | Transport & logistics | 2011 |
| SPT Global Ltd | Transport & logistics | 2026 |
| Spur International UK Ltd | Wholesale & retail | 2026 |
| SPX Solutions Ltd | Wholesale & retail | 2023 |
| Square Motors Ltd. | Administrative & support | 2024 |
| Squirrels Health Shop Limited | Wholesale & retail | 2017 |
| SR Film Services Limited | Other services | 2012 |
| SRA Cargo Connect Limited | Transport & logistics | 2026 |
| Sraan Investments Ltd | Real estate | 2014 |
| Sree Homes Limited | Real estate | 2020 |
| Sreeram Ltd | Information & communication | 2016 |
| SRI Chaitanya Saraswat Math. | Education | 1999 |
| SRI Estates Private Limited | Real estate | 2024 |
| SRI Ganesh Properties Limited | Real estate | 2023 |
| SRI Krsna Ventures Ltd | Other services | 2009 |
| SRI Lakshmi Properties Ltd | Real estate | 2022 |
| SRI Matha Consultancy Services Ltd | Information & communication | 2025 |
| SRI PVT Limited | Real estate | 2024 |
| SRI Shivapriya Consultancy Services Limited | Information & communication | 2011 |
| SRI Wealth Solutions Ltd | Professional & scientific | 2026 |
| Srimart Limited | Wholesale & retail | 2022 |
| Srimita Ltd | Real estate | 2025 |
| Sripad IT Solutions Limited | Information & communication | 2014 |
| Srirama Homes Limited | Real estate | 2024 |
| SRS Air Ltd | Construction | 2017 |
| SRS Orthopaedics Limited | Health & social care | 2015 |
| Srsm Estates Limited | Real estate | 2025 |
| SS Tech Ltd | Information & communication | 2008 |
| Ss&H Limited | Households | 2020 |
| SSB Investments Holdings Ltd | Financial services | 2020 |
| SSB Investments Limited | Real estate | 2003 |
| SSC Solutions Limited | Information & communication | 2021 |
| SSD GAS Heating Limited | Construction | 2016 |
| SSM Property Investment Group Limited | Real estate | 2026 |
| Ssmk Holdings Ltd | Real estate | 2021 |
| SSR Property Management Limited | Real estate | 2023 |
| SSS Haulage Limited | Transport & logistics | 2016 |
| ST Albans Day Nursery Limited | Education | 2010 |
| ST Dryliners Ltd | Construction | 2013 |
| ST Gabino's Food Limited | Hospitality | 2025 |
| ST George's Nursery Company Limited | Agriculture & fishing | 1935 |
| ST Giles Hotel (Heathrow) Limited | Hospitality | 1999 |
| ST Giles Hotel Limited | Hospitality | 1994 |
| St.Lucia Healthcare Management Ltd | Other services | 2017 |
| STA Digital Limited | Information & communication | 2020 |
| Staff Simple Ltd | Administrative & support | 2025 |
| Staffroots Ltd | Administrative & support | 2022 |
| Staines Rugby 1926 Community Interest Company | Education | 2025 |
| Stand Back Limited | Administrative & support | 2019 |
| Standpoint Consultants Ltd | Information & communication | 2011 |
| Stanex Fabrications Limited | Manufacturing | 1977 |
| Star Cakes Ltd | Wholesale & retail | 2018 |
| Star Experts Limited | Information & communication | 2023 |
| Star Rental Investments Ltd | Real estate | 2019 |
| Star Services & Solutions Ltd | Construction | 2006 |
| Star UK Ventures Limited | Real estate | 2018 |