| Southern Counties Car Deliveries Ltd. | Transport & logistics | 1995 |
| Southern Dream Stays Ltd | Real estate | 2025 |
| Southern Drives Hampshire Limited | Construction | 2026 |
| Southern Electrical Recycling Limited | Water & waste | 2018 |
| Southern Estate Services Limited | Administrative & support | 2015 |
| Southern Flat & Pitched Roofing Ltd | Construction | 2000 |
| Southern Graham & Sons Limited | Real estate | 2017 |
| Southern Imperial Investments Limited | Real estate | 2001 |
| Southern Liquid Screed Ltd | Construction | 2016 |
| Southern Paving Limited | Construction | 2011 |
| Southern Preservations Ltd | Construction | 2000 |
| Southern Property Reports Ltd | Real estate | 2023 |
| Southern Right Associates Limited | Real estate | 2014 |
| Southern Self Drive Limited | Professional & scientific | 1967 |
| Southern Shine Cleaning Ltd | Administrative & support | 2026 |
| Southern SKA Collective CIC | Arts & recreation | 2022 |
| Southern Smoke Control Ltd | Construction | 2017 |
| Southern Solar and Electrical Ltd | Construction | 2025 |
| Southern Spray Centre Ltd | Wholesale & retail | 2021 |
| Southern Surplus Ltd | Wholesale & retail | 2026 |
| Southern Utilities Ltd | Administrative & support | 2017 |
| Southern Van Guys Ltd | Wholesale & retail | 2022 |
| Southern Window & General Cleaning Company Limited | Administrative & support | 2000 |
| Southexcellensea Limited | Professional & scientific | 2015 |
| Southsea Anchors Ltd | Hospitality | 2023 |
| Southsea Apartments Ltd | Real estate | 2021 |
| Southsea Business Services Limited | Professional & scientific | 2011 |
| Southsea Carpentry Ltd | Extraterritorial | 2015 |
| Southsea Civils Ltd | Construction | 2023 |
| Southsea Cleaning Company Limited | Administrative & support | 2018 |
| Southsea Developments Ltd | Construction | 2017 |
| Southsea Electrical Ltd | Construction | 2020 |
| Southsea Financial Limited | Professional & scientific | 2001 |
| Southsea Interiors Limited | Construction | 2018 |
| Southsea Kebab Ltd | Hospitality | 2025 |
| Southsea Lifestyle Ltd | Information & communication | 2024 |
| Southsea Mechanical Ltd | Construction | 2016 |
| Southsea MOT Test Centre Limited | Wholesale & retail | 1996 |
| Southsea Properties Ltd | Real estate | 2023 |
| Southsea Property Developments Ltd | Real estate | 2024 |
| Southsea Real Estate Ltd | Professional & scientific | 2025 |
| Southsea Rental Solutions Ltd | Real estate | 2026 |
| Southsea Restaurant Ltd | Hospitality | 2018 |
| Southsea Skatepark Trading Ltd | Wholesale & retail | 2016 |
| Southsea Spice Ltd | Hospitality | 2026 |
| Southsea Strength Limited | Arts & recreation | 2017 |
| Southsea Terrace Management Limited | Real estate | 2023 |
| Southsea Tyres 4 U Limited | Wholesale & retail | 2020 |
| Southsea Workshop Unit Limited | Wholesale & retail | 2025 |
| Southway Construction Limited | Construction | 2015 |
| Southwick Homes Ltd | Real estate | 2021 |
| Southwick Homes One Ltd | Construction | 2024 |
| Southwicks Garden Rooms Ltd | Construction | 2018 |
| Southwold Pier Limited | Hospitality | 2023 |
| Southwood Management Limited | Households | 1991 |
| Sovereign Defence Ltd | Professional & scientific | 2025 |
| Sovereign Plus Contracting Limited | Construction | 2019 |
| Sovereign Plus Group Limited | Financial services | 2020 |
| Sovereign Plus Services Limited | Transport & logistics | 2021 |
| Sovereign Plus Solutions Limited | Construction | 2019 |
| Sovereign Rail Services Limited | Administrative & support | 2019 |
| Sovereign Workboats Ltd | Manufacturing | 2013 |
| SP Group Ltd | Wholesale & retail | 2025 |
| SP Home Improvements & Repairs Ltd | Construction | 2025 |
| SP Scaffolding Erectors Limited | Construction | 2024 |
| Space Genies Bicycles Ltd | Wholesale & retail | 2026 |
| Space Genies Delivery Ltd | Transport & logistics | 2026 |
| Space Genies Electricals Ltd | Wholesale & retail | 2026 |
| Space Genies Ltd | Water & waste | 2024 |
| Space Genies Nova Ltd | Wholesale & retail | 2026 |
| Space Genies Recovery Ltd | Wholesale & retail | 2026 |
| Space Genies TCG Ltd | Wholesale & retail | 2026 |
| Space Genies TCG Warehouse Ltd | Wholesale & retail | 2026 |
| Space Genies Toys Ltd | Wholesale & retail | 2026 |
| Space Genies Transport Ltd | Transport & logistics | 2026 |
| Space Genies Waste Ltd | Water & waste | 2026 |
| Space Renewable Energy Ltd | Construction | 2010 |
| Space Services Ltd | Construction | 2020 |
| Space TCG Genies Ltd | Wholesale & retail | 2026 |
| Spacespy Games Ltd | Arts & recreation | 2023 |
| Sparetime Foundation | Health & social care | 2022 |
| Sparetime Global Limited | Information & communication | 2021 |
| Spark Embers CIC | Administrative & support | 2024 |
| Sparkies Emporium Limited | Wholesale & retail | 2015 |
| Sparkle and Roar Limited | Professional & scientific | 2023 |
| Sparkle Craft Vinyl Limited | Wholesale & retail | 2021 |
| Sparkle Lodge CIC | Health & social care | 2018 |
| Sparkle Paws Ltd | Other services | 2018 |
| Sparkling White Care Ltd | Health & social care | 2025 |
| Sparkling White Care Services Ltd | Health & social care | 2020 |
| Sparks Building Developments Limited | Construction | 2014 |
| Spartan Fire UK Ltd | Other services | 2020 |
| SPB UK & Ireland Ltd | Professional & scientific | 2009 |
| Special Chinese Limited | Wholesale & retail | 2019 |
| Specialist Decor Limited | Construction | 1997 |
| Spectacular Funfairs Ltd | Arts & recreation | 2023 |
| Spectrum Interior Solutions Ltd | Construction | 2020 |
| Spectrum Workplace Limited | Professional & scientific | 2009 |
| Speedinno UK Ltd | Wholesale & retail | 2025 |
| Speedy Pizza Commercial Ltd | Hospitality | 2013 |