| SKD Real Estate Investment Limited | Construction | 2015 |
| Sketch Structural Engineering Limited | Professional & scientific | 2011 |
| Skinnygoose Ltd | Wholesale & retail | 2018 |
| Sky's Nails and Beauty Ltd | Other services | 2022 |
| Skycraft Propellers Limited | Manufacturing | 2022 |
| Slaters Property Investments Limited | Construction | 1999 |
| SLH Psychology Services Ltd | Education | 2023 |
| Sliderfy Ltd | Wholesale & retail | 2019 |
| Slkane Practice Limited | Public administration | 2019 |
| SMA Interim Ltd | Administrative & support | 2007 |
| Smart Business Tax Ltd | Professional & scientific | 2018 |
| Smart Coverings Ltd | Construction | 2018 |
| Smart Tabs Limited/ Ltd | Extraterritorial | 2019 |
| Smart TEC Limited | Construction | 2006 |
| Smashit Sports Ltd | Arts & recreation | 2022 |
| SMB1 Groundwork’S Limited | Administrative & support | 2025 |
| SMD Collections Ltd | Wholesale & retail | 2026 |
| SME Risk Solutions Ltd | Financial services | 2022 |
| Smith Associates Financial Services Ltd | Financial services | 2015 |
| SN Tax & Accounting Ltd | Professional & scientific | 2025 |
| Snag Pro Ltd | Professional & scientific | 2024 |
| Snoring Manor Farm Barns Management Company Limited | Extraterritorial | 2015 |
| Social Circular Economy Ltd | Professional & scientific | 2014 |
| Solanki Enterprises Ltd | Wholesale & retail | 2012 |
| Solanki PO and Hub Ltd | Transport & logistics | 2025 |
| Solarus Dent Consultancy Ltd | Professional & scientific | 2025 |
| Soma Services (UK) Ltd | Wholesale & retail | 2014 |
| Sophie Breitmeyer Limited | Manufacturing | 2023 |
| Sorex Sensors Limited | Professional & scientific | 2017 |
| Sound Connected Limited | Information & communication | 2014 |
| South Cambs Dog Training Club Limited | Education | 2024 |
| South Cambs Property Limited | Real estate | 2025 |
| South Cambs Property Services Ltd | Wholesale & retail | 2025 |
| South Farm Limited | Hospitality | 2009 |
| Soversa Ltd | Manufacturing | 2019 |
| Spanreach Limited | Real estate | 1987 |
| Speedarrive Projects Limited | Professional & scientific | 1993 |
| Spence Hospitality Ltd | Hospitality | 2024 |
| Spike Transport Services Ltd | Transport & logistics | 2012 |
| Spinview Films Limited | Information & communication | 2025 |
| Spitfire Inspire Ltd | Professional & scientific | 2019 |
| Spittalhill Limited | Agriculture & fishing | 2018 |
| Spot-Lit Limited | Education | 2021 |
| Sppp Limited | Real estate | 2015 |
| Spread'Em Ltd | Wholesale & retail | 2025 |
| Spring Solutions Limited | Manufacturing | 2019 |
| Springbeech Gardens Limited | Extraterritorial | 2018 |
| SPT Acquico Limited | Professional & scientific | 2018 |
| SPT Pledgeco Limited | Professional & scientific | 2018 |
| SPT Ventures Limited | Professional & scientific | 2018 |
| SRL Productions Ltd | Information & communication | 2024 |
| SRS Business Enterprises Limited | Professional & scientific | 2010 |
| Sseg Ltd | Construction | 2012 |
| ST Johns Investment House Limited | Financial services | 2018 |
| ST Surveyors Ltd | Professional & scientific | 2024 |
| Stamford Avenue Management Company Limited | Households | 1989 |
| Stamford Close Freehold Ltd | Households | 2020 |
| Stanley Holdco Limited | Energy | 2025 |
| Stanley J Murphy (Holdings) Limited | Real estate | 1964 |
| Stanley J. Murphy Limited | Real estate | 1979 |
| Stanley James Farming Limited | Agriculture & fishing | 2025 |
| Stanley Renewable Energy Ltd | Energy | 2011 |
| Stansted Airport Services Ltd | Transport & logistics | 2017 |
| Star Timber (UK) Ltd | Wholesale & retail | 2015 |
| Stardust I.T. Limited | Information & communication | 2000 |
| Starvene Limited | Professional & scientific | 2014 |
| Station Road Shepreth Limited | Real estate | 2009 |
| Stationery and Styling by the Guest List Ltd | Professional & scientific | 2024 |
| Stefanka Limited | Wholesale & retail | 2011 |
| Stellah Entertainment Limited | Information & communication | 2020 |
| Steve Barrett Maintenance Ltd | Construction | 2010 |
| Stevens Projects Limited | Construction | 2022 |
| Stewart Bullard & SON Limited | Other services | 2005 |
| STF Contracts Ltd | Construction | 2016 |
| Stolear Composites Ltd | Manufacturing | 2025 |
| Store Promotions Ltd | Transport & logistics | 2003 |
| Storigraphic Limited | Manufacturing | 2019 |
| Stormglass Consulting Ltd | Information & communication | 2019 |
| STRAIGHT2SLEEP Ltd | Manufacturing | 2022 |
| Streamline Foods Limited | Wholesale & retail | 1954 |
| Stronach Construction Limited | Construction | 2019 |
| Structovia Ltd | Construction | 2025 |
| Stuarts Way (Braintree) Limited | Households | 1987 |
| Stubbs and Stallion Ltd | Wholesale & retail | 2024 |
| Studenio Ltd | Education | 2015 |
| Studio 28 Interiors Limited | Construction | 2014 |
| Studio Astra Limited | Professional & scientific | 2024 |
| STUDIO24 Architects LLP | | 2012 |
| Styles + Partners Limited | Information & communication | 2007 |
| Success Scholars Ltd | Education | 2021 |
| SUE Cooke Recruitment Limited | Real estate | 1996 |
| Summer IT Solutions Ltd | Information & communication | 2024 |
| Summers Electrical & Partners Limited | Construction | 2011 |
| Summers Group Limited | Real estate | 2018 |
| Sunbelievable Ltd | Extraterritorial | 2021 |
| Sundown Management Limited | Wholesale & retail | 2020 |
| Supastrikers Royston Ltd | Arts & recreation | 2022 |
| Super Tiny Studios Ltd | Wholesale & retail | 2023 |
| Suppawt Dog Training Ltd | Other services | 2016 |
| Supportiveminds Ltd | Other services | 2025 |