| Seahaven Maritime Academy Ltd | Education | 2013 |
| Seahaven Music Ltd | Education | 2025 |
| Seahaven Properties Ltd | Real estate | 2024 |
| Seahaven Travel Limited | Transport & logistics | 2010 |
| Seathrough Accountancy Ltd | Professional & scientific | 2016 |
| Secured Area Services Limited | Administrative & support | 2012 |
| Selmeston Court (Seaford) Limited | Households | 2001 |
| Sennies Ltd | Health & social care | 2019 |
| Sgut-Mx Limited | Wholesale & retail | 2017 |
| Shoji Silkscreen Ltd | Manufacturing | 2024 |
| Shonichi Ltd | Wholesale & retail | 2024 |
| Sian Ashley TM Ltd | Construction | 2024 |
| Sigil Pro Audio Ltd | Wholesale & retail | 2025 |
| Silverdale Transport Limited | Transport & logistics | 1982 |
| Silverlock Construction Design Limited | Professional & scientific | 2017 |
| Simon John Flory Limited | Professional & scientific | 2010 |
| Simplepossible Ltd | Information & communication | 2026 |
| Sink OAR Swim Boats Ltd | Transport & logistics | 2019 |
| SJL Carpentry & Design Specialist Ltd | Construction | 2014 |
| SJP Cabs Ltd | Transport & logistics | 2015 |
| Skyline Holiday Lets Ltd | Hospitality | 2022 |
| Skyn & GLO Ltd | Other services | 2026 |
| SLG Logistics Ltd | Transport & logistics | 2021 |
| SM Plumbing-Heating Services Ltd | Construction | 2026 |
| Smartfish Medical Limited | Professional & scientific | 2005 |
| Smartwaste Skips Limited | Water & waste | 2011 |
| Sofstruct Ltd | Construction | 2020 |
| Soodoxco Limited | Wholesale & retail | 2025 |
| South Coast Flats Management Limited | Households | 2021 |
| South Coast Residential Ltd | Real estate | 2020 |
| South Downs Amateur Boxing Club CIC | Arts & recreation | 2025 |
| South Downs Catering Ltd | Hospitality | 2023 |
| Southcoast Asset Management Ltd | Real estate | 2016 |
| Southcoast Scaffolding Limited | Construction | 2008 |
| Southcoast Services Sussex Ltd | Administrative & support | 2018 |
| Southdowns Smokery Limited | Manufacturing | 2025 |
| Southern Counties Transport Ltd | Transport & logistics | 2014 |
| Southern Industrial Fasteners Limited | Wholesale & retail | 2003 |
| Southern Veedubz Limited | Wholesale & retail | 2014 |
| Southwick Print Limited | Manufacturing | 2011 |
| Sovereign House (Eastbourne) Limited | Households | 1998 |
| Spark Associates Ltd | Other services | 2006 |
| Specialist Training Consultants Ltd | Wholesale & retail | 1997 |
| Speedsilver Limited | Arts & recreation | 2020 |
| Spencer Lodge Limited | Real estate | 2003 |
| Sport & Leisure Investments Limited | Extraterritorial | 2012 |
| Square One Design Workshop Ltd. | Manufacturing | 2004 |
| SS & VEL Property Ltd | Real estate | 2020 |
| SS and VEL Limited | Wholesale & retail | 2017 |
| ST George's (Hurstpierpoint) Limited | Households | 2001 |
| ST. Crispians Residents Company (NO.1) Limited | Households | 1985 |
| ST. Kilda`S Management (Eastbourne) Limited | Households | 2005 |
| Staac Design Limited | Professional & scientific | 2017 |
| Stace Outdoor Ltd | Professional & scientific | 2020 |
| Standard Automobile UK Ltd | Wholesale & retail | 2023 |
| Starex Group Ltd | Transport & logistics | 2023 |
| Still Creative Ltd | Professional & scientific | 2016 |
| Stricklands Warehouse (Lewes) Limited | Extraterritorial | 2002 |
| Sublime Visual Solutions Ltd | Manufacturing | 2023 |
| Successful Direction Tutoring Ltd | Education | 2023 |
| Sunspark Electrical Ltd | Construction | 2025 |
| Supermoon Saunas Ltd | Health & social care | 2025 |
| Surf Collective Limited | Wholesale & retail | 2025 |
| Surrey Nanosystems Limited | Professional & scientific | 1999 |
| Sussex Art Projects CIC | Arts & recreation | 2023 |
| Sussex Bespoke Kitchens Ltd | Professional & scientific | 2025 |
| Sussex Blast Cleaning Limited | Administrative & support | 2000 |
| Sussex Blast Cleaning Site Ltd | Administrative & support | 2015 |
| Sussex Building Services (Brighton) Limited | Construction | 2010 |
| Sussex Catering & Hospitality Ltd | Hospitality | 2020 |
| Sussex Cleaning Company Limited | Administrative & support | 2020 |
| Sussex Community Development Association Ltd | Administrative & support | 1997 |
| Sussex Compliance Limited | Real estate | 2017 |
| Sussex Contracting Ltd | Construction | 2020 |
| Sussex Driveways (Paving) Limited | Construction | 1996 |
| Sussex Driveways Limited | Construction | 2003 |
| Sussex Staffing Solutions Limited | Administrative & support | 2021 |
| Sussex Tailored Removals Ltd | Transport & logistics | 2007 |
| Sutton Workboats Limited | Administrative & support | 2008 |
| SVR Sussex Vehicle Repairs & Electrics Limited | Wholesale & retail | 2020 |
| Swift-Team Care Limited | Health & social care | 2018 |
| Swoon Designs Ltd | Professional & scientific | 2019 |
| T S Civils & Drainage Ltd | Construction | 2026 |
| T-Tech Suspension Ltd | Manufacturing | 2022 |
| Take Good Care Limited | Health & social care | 2020 |
| Talentro Limited | Wholesale & retail | 2025 |
| Tappd Ltd | Wholesale & retail | 2020 |
| Tates of Sussex Limited | Financial services | 2017 |
| Tates Property Limited | Real estate | 2017 |
| Tech-Elec (South East) Ltd | Construction | 2026 |
| Technically Minded Ltd. | Information & communication | 2014 |
| Tennyson (Sussex) Limited | Extraterritorial | 2023 |
| Tennyson Suite Limited | Professional & scientific | 2007 |
| TEQ Limited | Manufacturing | 2023 |
| Terra Pura Limited | Manufacturing | 2008 |
| Teynham Penthouses Limited | Real estate | 2024 |
| THE Bloomsbury Group (Southern) Ltd | Construction | 2020 |
| THE Brighton and Hove Studio Ltd | Information & communication | 2013 |
| THE Consulting Group (UK) Limited | Construction | 2004 |
| THE Cumberland Court Right to Manage Company Limited | Households | 2008 |