| Smokecloak Limited | Professional & scientific | 2005 |
| SMW Garden Care Limited | Administrative & support | 2025 |
| Snac Group Ltd | Information & communication | 2024 |
| Snapshot Visualisations Ltd | Information & communication | 2023 |
| Sneaky Tints Limited | Other services | 2021 |
| SNP Refurb Limited | Construction | 2011 |
| Socktopus Limited | Manufacturing | 2018 |
| Socratic Learning Limited | Education | 2023 |
| Soho Dragon UK Limited | Information & communication | 2018 |
| SOI (Melton) Limited | Hospitality | 2013 |
| SOI Restaurants Ltd | Hospitality | 2011 |
| Sole House (Wholesale) Limited | Wholesale & retail | 2024 |
| Sole House Limited | Wholesale & retail | 2020 |
| Solidlink Property Management Limited | Real estate | 1990 |
| SOM PUB Ltd | Hospitality | 2023 |
| Somihan London Limited | Wholesale & retail | 2017 |
| Sonics & Materials (UK) Limited | Manufacturing | 2016 |
| South Downs Commercial Property Ltd | Real estate | 2024 |
| Southfields Leisure Limited | Manufacturing | 2007 |
| SP Trustees Limited | Financial services | 2014 |
| Spalding Common Development Number Two Limited | Construction | 2023 |
| Sparkling Teeth Ltd | Wholesale & retail | 2025 |
| Sparky Invest Limited | Financial services | 2023 |
| Spectranova Limited | Professional & scientific | 2025 |
| Spencer Wileman Ltd | Wholesale & retail | 2023 |
| Spice Mela Limited | Hospitality | 2015 |
| Spitfire Structural Engineering Limited | Construction | 2017 |
| Spokes Lettings Ltd | Real estate | 2026 |
| Sporting Edge Digital Limited | Arts & recreation | 2014 |
| Sporting Edge Solutions Limited | Arts & recreation | 2005 |
| SPORTMASSAGETHERAPY2020 Ltd | Health & social care | 2020 |
| Spring Place (Management Company) Limited | Households | 2007 |
| Sprinkles and Toppers Ltd | Hospitality | 2015 |
| SPU Consulting Ltd | Wholesale & retail | 2025 |
| Squared Away Consulting Ltd | Administrative & support | 2012 |
| Squared Away Digital Ltd | Information & communication | 2019 |
| Squeezy Cushion Ltd | Information & communication | 2017 |
| Squirrel Hoardings Ltd | Real estate | 2017 |
| SR Automotive Solutions Ltd | Professional & scientific | 2025 |
| SS Khan's Property Limited | Real estate | 2025 |
| Ssas Practitioner.Com Limited | Financial services | 2009 |
| Ssnj Roofing Ltd | Construction | 2026 |
| Ssrj Harborough Ltd | Wholesale & retail | 2026 |
| ST Georges Court, Winchester Limited | Real estate | 2024 |
| ST James Properties (Leicester) Limited | Real estate | 2020 |
| Stage MOM Enterprises Ltd | Information & communication | 2025 |
| Stamford Groundcare Ltd | Construction | 2026 |
| Stamps Away Limited | Wholesale & retail | 2011 |
| Stanbro Holdings Ltd | Manufacturing | 2017 |
| Staniforth Architects Limited | Administrative & support | 2007 |
| Stanley Plumbing Services Ltd | Construction | 2011 |
| Starfield Ventures Limited | Professional & scientific | 2025 |
| Starling Solutions Ltd | Information & communication | 2016 |
| Startplant Services Limited | Other services | 1993 |
| Startup Success Limited | Information & communication | 2020 |
| Station Motorsport Ltd | Manufacturing | 2011 |
| Stellarum Care Limited | Health & social care | 2022 |
| Stephen Sanderson Transport Holdings Limited | Financial services | 2013 |
| Stephen Sanderson Transport Limited | Wholesale & retail | 1986 |
| Sterling Solidus Ltd | Financial services | 2026 |
| Steven Bush Limited | Information & communication | 2007 |
| Stevradoja Ltd | Education | 2021 |
| Stirland Research Ltd | Professional & scientific | 2021 |
| Stone Lodge House Limited | Hospitality | 2022 |
| Stonemasons of Rutland Ltd | Manufacturing | 2017 |
| Stoneygate Developments Limited | Real estate | 2019 |
| Stonton Consulting LLP | | 2019 |
| Stonton Dynamics Ltd | Manufacturing | 2023 |
| Stoplaw Limited | Professional & scientific | 2003 |
| Stratanova Ltd | Professional & scientific | 2026 |
| Strategic Global Business Limited | Administrative & support | 2013 |
| STRATUS21 Limited | Information & communication | 2016 |
| Streamline Design & Build Ltd | Construction | 2025 |
| Street Smart Cleansing Limited | Administrative & support | 2005 |
| Stretton + Stretton Limited | Professional & scientific | 2013 |
| Stretton FOX Sports Ltd | Manufacturing | 2019 |
| Strickland House Limited | Real estate | 2021 |
| Stringfellow Property Lettings Limited | Real estate | 2016 |
| Striving Matters Ltd | Professional & scientific | 2019 |
| Structurax Holdings Limited | Financial services | 2026 |
| Studfall Laundry Room Ltd | Other services | 2023 |
| Studio 57 Limited | Other services | 2023 |
| Studio Detail Limited | Real estate | 2021 |
| Studio Lawson Ltd | Professional & scientific | 2020 |
| Studio Silks Limited | Wholesale & retail | 2005 |
| STUDIO5 Records Ltd | Administrative & support | 2024 |
| STUDIO62 Design Limited | Professional & scientific | 2015 |
| Subay Ltd | Hospitality | 2017 |
| Subtema Ltd | Information & communication | 2025 |
| Subtle Productions Limited | Information & communication | 2014 |
| Success Systems Limited | Information & communication | 1992 |
| Sugar & Giggles Ltd | Extraterritorial | 2022 |
| Sulby Reservoir Retreats Ltd | Hospitality | 2016 |
| Summerfield Browne Limited | Professional & scientific | 2012 |
| Sun Fence Engineering Limited | Professional & scientific | 2025 |
| Sunbeam Dataworks Ltd | Information & communication | 2024 |
| Sunbeam Property Solutions Ltd | Construction | 2025 |
| Sundridge Roadmarking Limited | Construction | 2021 |
| Sunkar Ltd | Wholesale & retail | 2026 |
| Sunshine UK Produce Limited | Wholesale & retail | 2022 |