| Scarchie Limited | Information & communication | 2008 |
| SCE Ayrshire Ltd | Professional & scientific | 2025 |
| SCE Caladonia Ltd | Professional & scientific | 2025 |
| SCG Global Limited | Manufacturing | 2026 |
| SCG IP Limited | Administrative & support | 2026 |
| Schloss Consulting Ltd | Administrative & support | 2013 |
| School for Wellbeing Ltd | Professional & scientific | 2016 |
| School House Nurseries Ltd | Education | 2017 |
| School House Nursery Uckfield Ltd | Education | 2017 |
| Scorpio Services Ltd | Professional & scientific | 2026 |
| Scott Developments Ltd | Construction | 2024 |
| Scott Electrical Ltd | Manufacturing | 2015 |
| Scott Ramsay Design Ltd | Professional & scientific | 2011 |
| Scotthawkesit Ltd | Information & communication | 2019 |
| Scrc Trading Limited | Wholesale & retail | 2024 |
| Scribewrite Ltd | Information & communication | 2009 |
| Scrubs Windows and Wheelies Ltd | Administrative & support | 2025 |
| SD Milano Ltd | Hospitality | 2022 |
| SD Sails Limited | Manufacturing | 2007 |
| SDH Biomass Limited | Wholesale & retail | 2017 |
| Sea Global PVT Ltd | Professional & scientific | 2014 |
| Sear Electrical Services Limited | Construction | 2012 |
| Sears Law Ltd | Professional & scientific | 2013 |
| Secret Agenda Limited | Administrative & support | 2004 |
| Section 41 Limited | Administrative & support | 2008 |
| Secure Dog Walking Field Surrey Ltd | Arts & recreation | 2021 |
| Secureswift Property Management Limited | Hospitality | 1994 |
| Seec Limited | Information & communication | 2000 |
| Selcroft Developments Ltd | Real estate | 2022 |
| SELDEK2025 Ltd | Hospitality | 2025 |
| Select Applications (UK) Limited | Agriculture & fishing | 2002 |
| Selus Supplies & Equipment Limited | Manufacturing | 1963 |
| Send IT 24-7 Ltd | Transport & logistics | 2013 |
| Sense Learning Collective C.I.C. | Health & social care | 2021 |
| Sensory Smart Supplies Limited | Education | 2012 |
| Seren Maria Education Ltd | Education | 2026 |
| Service, Supply & Development (UK) Limited | Administrative & support | 2021 |
| Servicematrix Ltd | Information & communication | 1992 |
| Services Marketplace Ltd | Other services | 2018 |
| Serviq Group Ltd | Administrative & support | 2026 |
| Servo Private Wealth Limited | Professional & scientific | 2019 |
| Servorbis Consulting Ltd | Information & communication | 2020 |
| SES Signs Limited | Construction | 1987 |
| Sessions Mews Management Company Limited | Households | 2019 |
| Seven Build Sussex Limited | Construction | 2024 |
| Seventy Seven Sports Limited | Arts & recreation | 2017 |
| Seventy-One Group Limited | Manufacturing | 1974 |
| Seventythree Queens Road Limited | Households | 2012 |
| SEW Perfect (Oxted) Limited | Other services | 2017 |
| SEW Perfect Limited | Other services | 2023 |
| Sewa Cleaning and Gardening Services Limited | Administrative & support | 2024 |
| Sewa Recruits Limited | Administrative & support | 2023 |
| Seyon Enterprise Ltd | Wholesale & retail | 2024 |
| SF Tailoring Ltd | Manufacturing | 2016 |
| SFP (Rights) Ltd | Administrative & support | 2003 |
| SG Staffing Limited | Administrative & support | 2025 |
| SGR Farming Ltd | Agriculture & fishing | 2020 |
| Sgsm Limited | Professional & scientific | 2016 |
| Shabs Electrical Ltd | Other services | 2017 |
| Shadbolt Limited | Health & social care | 2017 |
| Shadow Space Ltd | Hospitality | 2015 |
| Shaho Solutions Limited | Information & communication | 2024 |
| Shanico Property Limited | Real estate | 2024 |
| Share N Drive Ltd | Administrative & support | 2011 |
| Sharkbite Conversions Ltd | Wholesale & retail | 2023 |
| Sharp Nine Limited | Information & communication | 2020 |
| Sharpthorne Village Garage Limited | Wholesale & retail | 2006 |
| Sheeran's Shebeen Ltd | Professional & scientific | 2025 |
| Shehu Properties Ltd | Real estate | 2025 |
| Sheridan Management Consulting Limited Liability Partnership | | 2007 |
| Sheridanglobal D-A-Ch Limited | Professional & scientific | 2008 |
| Sheridanglobal Group Limited | Professional & scientific | 2007 |
| Sheridanglobal UK Limited | Professional & scientific | 2008 |
| Shia Company Limited | Construction | 2025 |
| Shieldline Roofing Ltd | Construction | 2026 |
| Shinpack Limited | Real estate | 1998 |
| Shire Barns Developments Limited Liability Partnership | | 2003 |
| Shire Barns Ltd | Construction | 1998 |
| Shirleys Residents Management Company Limited | Households | 2015 |
| Shivohum Limited | Professional & scientific | 2025 |
| Shootdays Limited | Wholesale & retail | 2007 |
| Shorefac Engineering Limited | Professional & scientific | 2017 |
| Shuttlers Academy Ltd | Other services | 2019 |
| Siamax Communications Ltd | Administrative & support | 2008 |
| Siamax Contracting Limited | Administrative & support | 2000 |
| Siamax Limited | Professional & scientific | 2005 |
| Siamax Power Ltd | Administrative & support | 2012 |
| Siamax Solutions Limited | Financial services | 2016 |
| Siamax Water Limited | Administrative & support | 2016 |
| Sian Keast Ltd | Information & communication | 2023 |
| Siben Management Ltd | Other services | 2014 |
| SIE (UK) Limited | Manufacturing | 2014 |
| Sierra Events UK Ltd. | Professional & scientific | 2017 |
| Sievewright & Co Ltd | Professional & scientific | 2025 |
| Sight Savers (Trading) Limited | Professional & scientific | 1990 |
| Signature Safaris Ltd | Administrative & support | 2021 |
| Sigpath Limited | Information & communication | 2022 |
| Siland Consulting Ltd | Information & communication | 2019 |
| Silvabak Construction Limited | Construction | 2019 |
| Silverdene Construction Limited | Construction | 2019 |