| Shorttech Ltd | Information & communication | 2018 |
| Show ME the Rabbit (Agency) Ltd | Professional & scientific | 2024 |
| Show ME the Rabbit Limited | Professional & scientific | 2009 |
| Showcase Classic & Sports Car Ltd | Other services | 2018 |
| Showmen Events Ltd | Administrative & support | 2020 |
| Showmen Group UK Ltd | Administrative & support | 2025 |
| Shutter Removal Reinstall Ltd | Construction | 2026 |
| Shweshwe Limited | Real estate | 2025 |
| Shwok Technology Consulting Ltd | Information & communication | 2016 |
| Side Design Limited | Professional & scientific | 2014 |
| Side Developments Ltd | Construction | 2018 |
| Side Limited | Manufacturing | 2001 |
| Side Products Limited | Manufacturing | 2001 |
| Sideband Pictures Limited | Information & communication | 2019 |
| Sidehill Limited | Other services | 2013 |
| Sidlesham (MOT) Limited | Wholesale & retail | 2018 |
| Sidlesham Garage Limited | Wholesale & retail | 2013 |
| Sidlesham Properties Ltd | Real estate | 2020 |
| Sidlesham Tyres Ltd | Wholesale & retail | 2015 |
| Silver Aries Limited | Financial services | 2023 |
| Silver First AID Ltd | Education | 2012 |
| Silver FOX Racing LLP | | 2013 |
| Silver Tree Consultancy Limited | Professional & scientific | 2023 |
| Silverbirch Solutions Limited | Professional & scientific | 2012 |
| Silverlock Window Cleaning Limited | Administrative & support | 2019 |
| Silverweb Business Solutions Limited | Information & communication | 2010 |
| Simmans Consulting Ltd | Information & communication | 2014 |
| Simmons Town Planning Ltd | Professional & scientific | 2018 |
| Simpatico PR Limited | Professional & scientific | 2010 |
| Simple Secure Finance Limited | Professional & scientific | 2016 |
| Simple Secure Loans Limited | Financial services | 2018 |
| Simplex Services (UK) Limited | Information & communication | 2014 |
| Simplification Ltd | Professional & scientific | 2015 |
| Simply Brands Limited | Wholesale & retail | 2007 |
| Simply Brilliance Limited | Professional & scientific | 2020 |
| Simply Cooling & Heating Hire Ltd | Energy | 2014 |
| Simply Developments Ltd | Construction | 2018 |
| Simply DP Limited | Professional & scientific | 2007 |
| Simply Paraplanning Ltd | Professional & scientific | 2016 |
| Simply Success Academy Ltd | Education | 2021 |
| Simpson Detour Limited | Professional & scientific | 1999 |
| Sims Williams Holdings Limited | Financial services | 2020 |
| Sims Williams Lettings Limited | Real estate | 2014 |
| Sims Williams LLP | | 2011 |
| Sincere Estate Views Ltd | Real estate | 2024 |
| SING2HEALTH CIC | Professional & scientific | 2025 |
| SIR Green Ltd | Wholesale & retail | 2019 |
| SIR Richard Hotham Project Ltd | Construction | 2014 |
| Sirocco Search Limited | Professional & scientific | 2015 |
| Sirotechnics Fireworks Ltd. | Arts & recreation | 2013 |
| SIX Acres Limited | Real estate | 2001 |
| SIX Foot Under Productions Ltd | Information & communication | 2024 |
| Sizelarge Traction Ltd | Other services | 2024 |
| SJ Edge Limited | Real estate | 2015 |
| SJB Property Garage Conversions Limited | Construction | 2018 |
| SJR Farms Ltd | Agriculture & fishing | 2018 |
| SJW Geoconsulting Ltd | Professional & scientific | 2019 |
| SK Logistics Holdings Limited | Financial services | 2022 |
| Skate Medical Limited | Health & social care | 2024 |
| Skate Ventures Limited | Financial services | 2026 |
| Skeller Limited | Construction | 2006 |
| Sketchit Limited | Professional & scientific | 2006 |
| Skiathos Services Ltd | Transport & logistics | 2025 |
| SKM Financial Ltd | Financial services | 2020 |
| Sky Blue Marina Management Limited | Real estate | 2013 |
| Sky Bros Ltd | Wholesale & retail | 2026 |
| Skye Properties (Sussex) Limited | Real estate | 2025 |
| Skyline Architectural Solutions Ltd | Extraterritorial | 2017 |
| Skyline Construction Solutions Ltd | Administrative & support | 2022 |
| Skyline Group Solutions Ltd | Administrative & support | 2016 |
| Skyline Structural Solutions Ltd | Extraterritorial | 2017 |
| Skyline Surveyors Limited | Information & communication | 2016 |
| Skytop Roofing SW Ltd | Construction | 2026 |
| Sleeping Bunnies Ltd | Wholesale & retail | 2021 |
| Slevin Wood Ltd | Manufacturing | 2024 |
| Slibs Ltd | Manufacturing | 2026 |
| Slim Gym's Properties Ltd | Real estate | 2024 |
| Slindon Electrical Services Ltd | Construction | 2009 |
| Sloane and Brown Ltd | Professional & scientific | 2015 |
| SLS Insight and Planning Limited | Professional & scientific | 2017 |
| SM Bespoke Builders Limited | Construction | 2016 |
| SM Bespoke Renovations Ltd | Construction | 2026 |
| SM Electrical Solutions 2 Limited | Energy | 2017 |
| SM Owners UK Limited | Other services | 2017 |
| Smada Holdings Limited | Financial services | 2016 |
| Small Garden Shop Ltd | Wholesale & retail | 2012 |
| Smallbase Limited | Households | 1987 |
| Smart Couriers Solutions Ltd | Transport & logistics | 2016 |
| Smart Futures Limited | Professional & scientific | 2004 |
| Smart Gadgets Solution Ltd | Wholesale & retail | 2025 |
| Smart Tecc Electrical Ltd | Construction | 2019 |
| Smartraft Ltd | Manufacturing | 2020 |
| Smduk Limited | Wholesale & retail | 2016 |
| Smile Assist (UK) Ltd | Wholesale & retail | 2019 |
| Smile Krafters Ltd | Health & social care | 2024 |
| Smingle Ltd | Information & communication | 2023 |
| Smith Simmons & Partners Ltd | Construction | 2017 |
| Smith Simmons Group Ltd | Construction | 2020 |
| Smithereen Music Group Limited | Information & communication | 2023 |
| Smoking APE Effects Ltd | Information & communication | 2023 |