| S-Lord Marine Ltd | Transport & logistics | 2014 |
| S-M Glass Ltd | Construction | 2022 |
| S. G. Property Investments Ltd. | Real estate | 2001 |
| S. Wells Plumbing & Heating Ltd | Construction | 2013 |
| S.Africa Capron Seaweed Co., Ltd | Mining & quarrying | 2024 |
| S.C. International Trade Co., Ltd | Wholesale & retail | 2025 |
| S.H International Trading Co., Limited | Manufacturing | 2017 |
| S.J. & C.A. Fisher Properties Ltd. | Real estate | 2004 |
| S.O.M.S Helicopters Ltd | Manufacturing | 2025 |
| S.R Auto Tech Ltd | Wholesale & retail | 2023 |
| S.T. Precision Limited | Professional & scientific | 2026 |
| S.Y. Ventures Ltd | Administrative & support | 2018 |
| S4 Technosolutions Ltd | Information & communication | 2025 |
| S7 Nutrition Partners Ltd | Health & social care | 2026 |
| SA Laundry Ltd | Other services | 2023 |
| SA Link Limited | Transport & logistics | 2016 |
| SA Squared Limited | Health & social care | 2020 |
| Sabai London Limited | Wholesale & retail | 2025 |
| Saberton Close Waterbeach Management Company Limited | Real estate | 2012 |
| Sabir Plus Limited | Health & social care | 2017 |
| Sable and Hawkes Limited | Information & communication | 2012 |
| Sable Spire Ltd | Information & communication | 2025 |
| Sabre Estate Management Limited | Real estate | 2022 |
| Saccnew Limited | Wholesale & retail | 2022 |
| Sachiko Ltd | Information & communication | 2018 |
| Sacraf ARY Ltd | Manufacturing | 2025 |
| Sacred Facilities Solution Limited | Administrative & support | 2025 |
| Sacred Leadership Consultancy Limited | Education | 2025 |
| Saddlers Place (Royston) Limited | Households | 1993 |
| Saf-X Trading Limited | Agriculture & fishing | 2025 |
| Safa Property Solutions Ltd | Real estate | 2025 |
| Safari Service Station Limited | Financial services | 1973 |
| Safari Trade Limited | Wholesale & retail | 2024 |
| Safe Depot Limited | Real estate | 2002 |
| Safe Oceans Limited | Professional & scientific | 2021 |
| Safe Pipelines Limited | Energy | 2023 |
| Safe Seas Ltd | Professional & scientific | 2019 |
| Safe Soulmates Community Interest Company | Health & social care | 2018 |
| Safebiomed Consultancy Limited | Information & communication | 2021 |
| Safegear Ltd | Manufacturing | 2025 |
| Safehands Solutions Ltd | Construction | 2025 |
| Safelok Valve Group Limited | Manufacturing | 2026 |
| Safely BIO Ltd | Information & communication | 2026 |
| Safer Property Solutions (Cambridge) Limited | Construction | 2025 |
| Safer Tappers Ltd | Transport & logistics | 2026 |
| Safeseal Eastern Limited | Construction | 2014 |
| Safeseal Frames Limited | Manufacturing | 2013 |
| Safeswitch Electrical Limited | Construction | 2016 |
| Safety BUG Training Ltd | Education | 2012 |
| Safety Decking Ltd | Construction | 2011 |
| Safety Protection Logistics Limited | Wholesale & retail | 2005 |
| Safety Services Group Limited | Extraterritorial | 2008 |
| Saffan Ltd | Wholesale & retail | 2001 |
| Saffron City Ltd | Real estate | 2021 |
| Saffron Court (Reading) Management Company Limited | Households | 2007 |
| Saffron Development Ltd. | Professional & scientific | 2005 |
| Saffron Estates (ELM Leys) Ltd | Construction | 2019 |
| Saffron Grange Vineyard Limited | Manufacturing | 2008 |
| Saffron House Management Company Limited | Households | 2006 |
| Saffron Rise Management Company Limited | Households | 2022 |
| Saffron Scaffolding Ltd | Extraterritorial | 2022 |
| Saffron Security Ltd | Construction | 2006 |
| Saffron Vantage Ltd | Administrative & support | 2019 |
| Saffron Walden Bouncy Castles Limited | Administrative & support | 2016 |
| Saffron Walden Haematology Limited | Other services | 2023 |
| Saffron Walden Sushi Limited | Hospitality | 2022 |
| Saga Diagnostics UK Limited | Professional & scientific | 2023 |
| Sagax Partnerspt Co., Limited | Wholesale & retail | 2025 |
| Sage Events & Weddings Ltd | Other services | 2022 |
| Sage Exteriors Limited | Professional & scientific | 2005 |
| Sage Stein Properties Ltd | Real estate | 2025 |
| Sagelife Diagnostics Limited | Health & social care | 2025 |
| Sagentia Limited | Professional & scientific | 1986 |
| Sagoos Design & Build Ltd | Construction | 2025 |
| Sagoos Estates Limited | Real estate | 2024 |
| SAH Town Planning Ltd | Professional & scientific | 2025 |
| Sahaque Limited | Transport & logistics | 2014 |
| Sahara Biomedix Ltd | Manufacturing | 2018 |
| Saher Ahmed Consultancy Limited | Education | 2024 |
| Sahira Ltd | Health & social care | 2024 |
| SAI Assosiates Limited | Education | 2019 |
| SAI Gohil Limited | Real estate | 2023 |
| SAI VRP & Sons Ltd | Construction | 2018 |
| Sail Link Trading Group Limited | Extraterritorial | 2025 |
| Sail Technologies Limited | Information & communication | 2019 |
| Sain Import&Export Trading Co., Limited | Wholesale & retail | 2015 |
| Sainaptic Limited | Information & communication | 2020 |
| Saint Andrews Bureau Limited | Real estate | 1959 |
| Saints Pool and Sports Club Limited | Arts & recreation | 2024 |
| Saiv LP | | 2018 |
| Sajda Ltd | Professional & scientific | 2024 |
| SAK (UK) Limited | Health & social care | 2011 |
| Sakura Consulting Ltd | Information & communication | 2023 |
| Sakura Design Studio Limited | Professional & scientific | 2004 |
| Saky Steel Co., Limited | Extraterritorial | 2014 |
| Sala Thong (Stevenage) Limited | Hospitality | 2015 |
| Sala Thong Thai Restaurant (Cambridge) Limited | Hospitality | 2004 |
| Salamander Biosciences Ltd | Professional & scientific | 2014 |
| Salamander R&D Ltd | Professional & scientific | 2014 |
| Salbro (UK) Fertilizers Co., Ltd | Wholesale & retail | 2023 |