| Squeeky Shine Limited | Administrative & support | 2025 |
| Squishy Squashy Slimes Ltd | Professional & scientific | 2019 |
| SR Building & Roofing Limited | Construction | 2016 |
| SR Technics UK Limited | Transport & logistics | 1919 |
| Sree Sumanth Estates Ltd | Real estate | 2018 |
| Sree Sumanth UK Limited | Information & communication | 2009 |
| SRI SAI RAM Kalp's PVT. Ltd | Information & communication | 2010 |
| SRK Safety & Compliance Consultants Ltd | Construction | 2023 |
| SRL Holdings Ltd | Real estate | 2021 |
| SRP M&E Consultants Ltd | Professional & scientific | 2025 |
| SRS Electrical Innovations Limited | Energy | 2010 |
| SRU Limited | Professional & scientific | 2003 |
| SS Global Consulting Limited | Information & communication | 2013 |
| SSD Aviation Group Ltd | Transport & logistics | 2017 |
| Ssrh Property Group Ltd | Construction | 2024 |
| Ssrk Software Limited | Information & communication | 2015 |
| SSS Noodles Ltd | Hospitality | 2025 |
| ST Botolphs Court (Worthing) RTM Limited | Households | 2014 |
| ST Giorgio Ristorante Italiano Ltd | Hospitality | 2020 |
| ST Johns Court Limited | Households | 2005 |
| ST Lawrence Mews Management Company (Worthing) Limited | Households | 2008 |
| ST Malo Court Management Company Limited | Households | 1963 |
| ST Mary's Square (Kemp Town) Residents Association Limited | Households | 1988 |
| ST Michaels Court (Lancing) RTM Company Limited | Households | 2015 |
| ST Winefrides Court Management Ltd | Households | 2019 |
| ST. Aubins Court Residents Association Limited | Real estate | 1965 |
| ST. Catherines Court Residents Association Limited | Households | 2001 |
| ST. George's Court Residents Association (Hove) Limited | Households | 1986 |
| ST. Helier Road Flats Residents Association Limited | Households | 1964 |
| ST. Mary's Court (Littlehampton) Management Limited | Households | 1989 |
| ST. Mary's Garden (Management) Limited | Administrative & support | 1969 |
| St.Andrews Gardens Management Limited | Real estate | 1965 |
| Stable Home & Garden Limited | Wholesale & retail | 2022 |
| Stable Properties & Management Ltd | Real estate | 2025 |
| Stacked Mgmt Ltd | Information & communication | 2026 |
| Stafford Johnson Limited | Real estate | 2000 |
| Stage Mode Production Limited | Arts & recreation | 2020 |
| Stage Modes Limited | Transport & logistics | 2020 |
| Stage Perfect Engineering Ltd | Professional & scientific | 2014 |
| Stainger Glass Limited | Manufacturing | 2002 |
| Stan LEE Holdings Limited | Health & social care | 2011 |
| Standish and Sons Ltd | Information & communication | 2010 |
| Stanmer Organics Limited | Other services | 1997 |
| Stanton Engineering Group Limited | Manufacturing | 2018 |
| Stark Circle Limited | Administrative & support | 2018 |
| Starkport Limited | Professional & scientific | 2002 |
| Startco Limited | Extraterritorial | 1995 |
| Stasko Logistic Ltd | Transport & logistics | 2019 |
| Stately Estates Ltd | Extraterritorial | 2013 |
| Stately Homes Ltd | Real estate | 2013 |
| Stately Homes Ridgeway Ltd | Construction | 2018 |
| Stately Interiors Ltd | Administrative & support | 2018 |
| Station Road HCW Ltd | Other services | 2015 |
| Statuman Limited | Information & communication | 2023 |
| Statumen Apmc Limited | Information & communication | 2018 |
| Statumen International Limited | Information & communication | 2008 |
| Statumen Limited | Information & communication | 2000 |
| Stay Curious Ltd | Information & communication | 2019 |
| Stearth Entertainments Ltd | Information & communication | 2019 |
| Steddles Limited | Real estate | 2017 |
| Steedman Holdings Limited | Real estate | 2018 |
| Steel & Form Ltd | Manufacturing | 2019 |
| Steele Fieldworks Limited | Professional & scientific | 2011 |
| Steele Motor Cycle Logistics Limited | Transport & logistics | 2022 |
| Steele's Building Contractors Limited | Construction | 2019 |
| Steeles Investments Limited | Professional & scientific | 2008 |
| Steeles of Ferring Limited | Construction | 2013 |
| Steelgear Ltd | Administrative & support | 2017 |
| Stem Innovation Consultancy Ltd | Professional & scientific | 2021 |
| Stem Innovation Education Ltd | Education | 2023 |
| Stem Innovation Ltd | Education | 2020 |
| Stepfastik Ltd | Wholesale & retail | 2022 |
| Stephen Charman Limited | Construction | 2003 |
| Stephen Theakston Limited | Manufacturing | 2003 |
| Stephenson Mortgage Solutions Limited | Financial services | 2021 |
| Stepping Stones Counselling and Psychotherapy Limited | Health & social care | 2020 |
| Steps 2 Limited | Other services | 2010 |
| Stereovision Ltd | Health & social care | 2024 |
| Sterk Foods Ltd | Wholesale & retail | 2018 |
| Sterling Group (Sussex) Limited | Financial services | 2017 |
| Sterling Home Concierge Limited | Administrative & support | 2026 |
| Sterling Power Tools & Fixings Limited | Wholesale & retail | 2007 |
| Sterling Vault Auctioneers Limited | Wholesale & retail | 2016 |
| Steve Apollo Limited | Other services | 2018 |
| Steve's Auto Lancing Limited | Wholesale & retail | 2018 |
| Steve's Auto Repairs Limited | Wholesale & retail | 2012 |
| Stevenson Original Works Ltd | Professional & scientific | 2018 |
| Stewart and FOX Marketing Ltd | Professional & scientific | 2022 |
| Steyne Hotels Limited | Hospitality | 2001 |
| Steyne Properties Limited | Real estate | 2015 |
| Steyning Festival Limited | Arts & recreation | 2008 |
| Steyning Gallery Limited | Real estate | 2013 |
| Sticky PAW Games Ltd | Information & communication | 2026 |
| Stickybun Media Limited | Professional & scientific | 2013 |
| Stiff Drinks Ltd | Wholesale & retail | 2026 |
| Still Water Property Investments Limited | Real estate | 2018 |
| Stitch Productions Limited | Information & communication | 2015 |
| Stitchr Talent Ltd | Administrative & support | 2025 |
| STJ Project Consultants Ltd | Professional & scientific | 2026 |
| STJ Property Investment Ltd | Real estate | 2024 |