| Solutions With Wings Ltd | Information & communication | 2024 |
| Soma Agency Limited | Administrative & support | 2022 |
| Sonnet Court RTM Company Limited | Households | 2023 |
| Source Vero Ltd | Construction | 2025 |
| South Downs Bikes Cycling Club Ltd | Arts & recreation | 2014 |
| South Downs Emergency Vets Limited | Professional & scientific | 2017 |
| South Downs Energy Limited | Professional & scientific | 2021 |
| South Downs Light Railway Society Limited | Arts & recreation | 2007 |
| South Downs Mountain Sports Limited | Information & communication | 2007 |
| South Downs RAW Limited | Wholesale & retail | 2024 |
| South Downs Veterinary Referrals Limited | Professional & scientific | 2022 |
| Southdown Safety Solutions Ltd | Professional & scientific | 2011 |
| Southern Contract Lifting Ltd | Extraterritorial | 1997 |
| Southern Cranes Limited | Construction | 2017 |
| Southern Engineering U.K. Ltd | Professional & scientific | 2025 |
| Southern Fleet Services Ltd | Wholesale & retail | 2013 |
| Southern Lifting Limited | Construction | 2017 |
| Southern Marine Engineering Ltd | Administrative & support | 2021 |
| Southern Security Ltd | Administrative & support | 2025 |
| Southern Tax & Accounts Limited | Professional & scientific | 2012 |
| Southern Training Limited | Construction | 2017 |
| Spanish Foody Ltd | Extraterritorial | 2019 |
| Special Delivery ZW Ltd | Wholesale & retail | 2020 |
| Specialist Tutor Ltd | Education | 2024 |
| Spellman High Voltage Electronics Limited. | Manufacturing | 1988 |
| SPG Air Conditioning Services Ltd | Energy | 2019 |
| Spicy Mahal Ltd | Hospitality | 2025 |
| Spiral Publishing Limited | Manufacturing | 2001 |
| Spofforth Partners Limited | Professional & scientific | 2018 |
| Springgreen Payroll Services Limited | Administrative & support | 2018 |
| Springhead Woodland Enterprises Limited | Manufacturing | 2000 |
| Spyder Finance Ltd | Administrative & support | 2017 |
| SRL Renewable Ltd | Construction | 2023 |
| Stage Door Tickets Ltd | Administrative & support | 2009 |
| Stancombe Estate Management Company Limited | Administrative & support | 2006 |
| Start Spellman Holdings Limited | Professional & scientific | 1990 |
| Status Training Limited | Administrative & support | 2020 |
| Steve Jones Property Maintenance Limited | Construction | 2019 |
| Stitch of Storrington Limited | Wholesale & retail | 2021 |
| Stockframe Limited | Construction | 2005 |
| Stopham House Management Limited | Households | 1990 |
| Stopham Vineyard Ltd | Manufacturing | 2008 |
| Stor Court Limited | Households | 2001 |
| Storc Ltd | Wholesale & retail | 2025 |
| Storrington Bowling Club Ltd | Arts & recreation | 2025 |
| Storrington Car Parts & Accessories Limited | Wholesale & retail | 2002 |
| Storrington Contractors Limited | Extraterritorial | 1958 |
| Storrington Gradient Limited | Administrative & support | 2025 |
| Storrington Home Improvements Ltd | Construction | 2024 |
| Storrington IT Consultants Limited | Information & communication | 2008 |
| Storroak Limited | Administrative & support | 1983 |
| Such Books AS Films ARE Made of Ltd. | Information & communication | 2018 |
| Sullington Manor Farm Limited | Agriculture & fishing | 1953 |
| Summit Details Limited | Wholesale & retail | 2024 |
| Sunbourne Property Company Limited | Hospitality | 1986 |
| Sunrise Spice Ltd | Hospitality | 2024 |
| Sunshine Design 52 Ltd | Professional & scientific | 2020 |
| Super Medics Education Ltd | Other services | 2021 |
| Super Medics Ltd | Education | 2019 |
| Suri Design Studio Ltd | Professional & scientific | 2025 |
| Sussex Caravan Properties Limited | Financial services | 2004 |
| Sussex Countryside Management Ltd | Agriculture & fishing | 2010 |
| Sussex Harvest Ltd | Agriculture & fishing | 2026 |
| Sussex Nurseries Limited | Education | 2024 |
| Sussex Salt Therapy Ltd | Other services | 2025 |
| Sussex Valeting Limited | Administrative & support | 2023 |
| Sustainabuild Sussex Ltd | Construction | 2023 |
| Swan Close (Ashington) Management Company Limited | Real estate | 2022 |
| Sweetwater Design Limited | Professional & scientific | 2020 |
| Sylvan Nurseries (Pulborough) Limited | Agriculture & fishing | 1977 |
| Syncline Industrial Properties Limited | Hospitality | 1996 |
| T Kenny Fencing Services Ltd | Construction | 2025 |
| Tacama Plant and Excavations Ltd | Other services | 2015 |
| Tailored Wealth & Trust Management Limited | Financial services | 2013 |
| Tallulah Telecom Limited | Information & communication | 2025 |
| Tandem Collective Limited | Professional & scientific | 2016 |
| Tapazoom Capital Limited | Agriculture & fishing | 2023 |
| Taps & Toilets Ltd | Construction | 2022 |
| Tatum Property Limited | Real estate | 2019 |
| TBM Productions Ltd | Information & communication | 2019 |
| Teaghlach HW Ltd | Real estate | 2026 |
| Technostate Limited | Information & communication | 1988 |
| Teeuuconsulting Ltd | Information & communication | 2026 |
| TEN Eight Seven Mastering Ltd | Information & communication | 2011 |
| Tesla Magnetic Limited | Extraterritorial | 1999 |
| Tesson Consulting Limited | Real estate | 2014 |
| Tetreon Technologies Group Limited | Financial services | 2019 |
| Tetreon Technologies Limited | Manufacturing | 2018 |
| Teville Road Limited | Construction | 2022 |
| TF Sport Ltd | Professional & scientific | 2013 |
| Thai Wellness Spa & Yensabai Ltd | Other services | 2026 |
| Thakeham Consultants Ltd | Professional & scientific | 2012 |
| Thakeham Consulting (Sussex) Ltd | Professional & scientific | 2023 |
| Thakeham Consulting Limited | Professional & scientific | 2018 |
| Thakeham Manor Limited | Real estate | 2021 |
| THE 4X4 Specialists Ltd | Wholesale & retail | 2020 |
| THE Acuity Key Ltd | Health & social care | 2021 |
| THE Agency-Uk.Com Limited | Administrative & support | 2005 |
| THE Badminton Zone Limited | Education | 2023 |
| THE Bicycle Exchange Ltd | Wholesale & retail | 2021 |