| Snug Rugs Limited | Wholesale & retail | 2011 |
| SO Skin Kent Ltd | Health & social care | 2023 |
| Soapisticated London Ltd | Manufacturing | 2018 |
| Sobral UK Ltd | Construction | 2020 |
| SOC Spares Limited | Manufacturing | 1984 |
| Social Local Limited | Hospitality | 2023 |
| Sociodigi Limited | Wholesale & retail | 2025 |
| Sogl Business Services Ltd | Administrative & support | 2025 |
| Soho Furniture Supply Ltd | Wholesale & retail | 2024 |
| Sojel Lighthouse Ltd | Education | 2025 |
| SOL Tint Ltd | Construction | 2008 |
| Solak Catering Limited | Hospitality | 2025 |
| Solarbright Renewables Ltd | Construction | 2024 |
| Solaris Wellness Ltd | Education | 2024 |
| Solidarity Bromley Ltd | Real estate | 2024 |
| Solo Group Limited | Professional & scientific | 1988 |
| Solomon Carpentry Limited | Construction | 2019 |
| Solsbury Holdings Limited | Financial services | 2023 |
| Soluna House Limited | Other services | 2025 |
| Solution Cell Holdings Limited | Financial services | 2017 |
| Solution Cell Limited | Professional & scientific | 2000 |
| Solution One Resources Limited | Administrative & support | 2007 |
| Solution Pest Control Ltd | Administrative & support | 2008 |
| Solution Provider Ltd | Professional & scientific | 1987 |
| Solutions for Information Management Limited | Information & communication | 1999 |
| Solvex Energy and IT Ltd | Construction | 2026 |
| Somily Ltd | Professional & scientific | 2023 |
| Sonas Wellbeing Ltd | Professional & scientific | 2017 |
| Sonevaa Limited | Wholesale & retail | 2025 |
| Songfab Limited | Wholesale & retail | 2026 |
| Songreen Ltd | Wholesale & retail | 2020 |
| Sonia Tome Urresti Ltd | Professional & scientific | 2024 |
| Sonigo Ltd | Real estate | 2020 |
| Soot Happens Ltd | Administrative & support | 2025 |
| Sophie Grace Bridal Limited | Wholesale & retail | 2015 |
| Sophie Hunt Osteopathy Limited | Health & social care | 2015 |
| Sophus Safety Solutions Ltd | Professional & scientific | 2023 |
| Sorbaes Ltd | Hospitality | 2025 |
| Sorella Aesthetics Ltd | Health & social care | 2023 |
| Sorlfa Infrastructure Design Services Ltd | Professional & scientific | 2019 |
| SOS Whitstable Ltd | Other services | 2023 |
| Soul Academy Ltd | Wholesale & retail | 2016 |
| Soul Supplements Ltd | Wholesale & retail | 2024 |
| Soul Supps Limited | Information & communication | 2023 |
| Soulhouse Enterprises Ltd | Professional & scientific | 2017 |
| Soulmate Spirits Ltd | Wholesale & retail | 2022 |
| Sound Engineering Limited | Manufacturing | 1995 |
| Sound Ideas U.K. Limited | Extraterritorial | 2017 |
| Sound Works Services Ltd | Information & communication | 2010 |
| Soundcraft (Kent) Holdings Limited | Financial services | 2020 |
| Souqustudio Ltd | Professional & scientific | 2022 |
| South Central (UK) Ltd | Construction | 2023 |
| South Coast Shutters Ltd | Administrative & support | 2008 |
| South East Accounting Ltd | Professional & scientific | 2025 |
| South East Airsoft Supplies Ltd | Wholesale & retail | 2017 |
| South East Bookkeeping Limited | Professional & scientific | 2018 |
| South East Engineering Services Limited | Professional & scientific | 2023 |
| South East Facades Ltd | Construction | 2019 |
| South East Farm Supplies Ltd | Wholesale & retail | 2020 |
| South East Gates Ltd | Construction | 2026 |
| South East Gates T/A SEG Installations Limited | Construction | 1999 |
| South East Land Services Ltd | Real estate | 2025 |
| South East M&E Limited | Construction | 2014 |
| South East PH Limited | Hospitality | 2012 |
| South East Property Care Limited | Construction | 2026 |
| South East Scaffolding Ltd | Construction | 2023 |
| South East Security Solutions Ltd | Wholesale & retail | 2026 |
| South East Stainless Limited | Manufacturing | 1999 |
| South East Tile & Bathroom Supplies Ltd | Wholesale & retail | 2025 |
| South East Timber and Damp Limited | Construction | 2005 |
| South East Transits Limited | Wholesale & retail | 2022 |
| South East Tyre Recycling Limited | Water & waste | 2025 |
| South East Weather Protection Ltd | Construction | 2025 |
| South East Youth Action CIC | Education | 2024 |
| South Eastern Foods Limited | Wholesale & retail | 1987 |
| South Eastern Trading Company Limited | Other services | 1956 |
| South Stour Consultancy Ltd | Information & communication | 2018 |
| South Stour Limited | Real estate | 2016 |
| South View Property Limited | Construction | 2022 |
| Southcliff Developments Limited | Construction | 2023 |
| Southcote Proactive Healthcare Ltd | Health & social care | 2018 |
| Southeast Flowers Limited | Wholesale & retail | 2009 |
| Southern and Country Construction and Development Ltd | Construction | 2015 |
| Southern and Country Roofing Ltd | Construction | 2008 |
| Southern Cesspool Services Limited | Administrative & support | 2015 |
| Southern Cladding Ltd | Construction | 2015 |
| Southern Counties OFF Road Club Limited | Other services | 1994 |
| Southern Electrical Limited | Construction | 2023 |
| Southern Foster Care Limited | Health & social care | 1996 |
| Southern Manor Holdings Limited | Real estate | 2019 |
| Southfield Rural Properties Ltd | Real estate | 2024 |
| Southside Rail Limited | Transport & logistics | 2022 |
| Southside Rail Training Limited | Education | 2018 |
| Southwell Property Ltd | Real estate | 2019 |
| Southwood Design & Build Limited | Construction | 2008 |
| Sovereign Business Equipment Limited | Real estate | 1986 |
| Sovereign Hart Games Ltd | Manufacturing | 2020 |
| SOX Seaton Limited | Administrative & support | 2021 |
| SP Bespoke Limited | Manufacturing | 2022 |
| Space 4 Time Ltd | Transport & logistics | 2023 |