| SMH Resins Ltd | Construction | 2025 |
| Smile Dental Laboratory Ltd | Manufacturing | 2017 |
| Smile NOW Ltd | Wholesale & retail | 2015 |
| Smith and Hurley Limited | Real estate | 2025 |
| Smith Capital Group Ltd | Professional & scientific | 2026 |
| Smith Driver Training Ltd | Education | 2023 |
| Smith Group Co Holdings Ltd | Financial services | 2026 |
| Smith Group Co Management Ltd | Construction | 2013 |
| Smith Made Design Ltd | Professional & scientific | 2026 |
| Smith REB Contracting Limited | Construction | 2025 |
| Smjj Ltd | Real estate | 2026 |
| Smock Public House Ltd | Hospitality | 2024 |
| Smokey EYE Limited | Hospitality | 2026 |
| Smoochy Brands Ltd | Administrative & support | 2014 |
| Smre Ltd | Other services | 2019 |
| Smre Property Ltd | Real estate | 2019 |
| SMT Electrical Services & Sons Limited | Construction | 2018 |
| Smugglers Catering Limited | Hospitality | 2013 |
| SMY Property Limited | Real estate | 2020 |
| SN Property Holdings Ltd | Real estate | 2025 |
| SN Supermart Ltd | Wholesale & retail | 2026 |
| Snakes Alive Limited | Other services | 2015 |
| Snap & Deliver Ltd | Professional & scientific | 2026 |
| SNB Properties London Limited | Real estate | 2025 |
| Snell Salons Ltd | Other services | 2023 |
| SNF Property Ltd | Real estate | 2023 |
| SNK & ABI Ltd | Transport & logistics | 2018 |
| Snovia Designer Ltd | Wholesale & retail | 2025 |
| Snowdrop Pantry Ltd | Hospitality | 2024 |
| Snuggle Life Ltd | Real estate | 2024 |
| SNZ Medical Ltd | Health & social care | 2012 |
| SO BE IT Holdings Limited | Financial services | 2022 |
| SO Crocodile Ltd | Information & communication | 2021 |
| Soapbox Spoken Word CIC | Arts & recreation | 2024 |
| Soar Freston Limited | Construction | 2005 |
| Soares Services Limited | Transport & logistics | 2017 |
| Sobe A&E Ltd | Hospitality | 2025 |
| Sobela Holdings Limited | Real estate | 2024 |
| Sobzub Health Limited | Health & social care | 2025 |
| Socialpal Pro Ltd | Information & communication | 2019 |
| Sofa Design Ltd. | Manufacturing | 2018 |
| Soff Ltd | Information & communication | 2025 |
| SOFIA88 Ltd | Transport & logistics | 2022 |
| Softjenic Solutions Ltd | Wholesale & retail | 2021 |
| Softwood Consulting Ltd | Professional & scientific | 2016 |
| Sogmg Ltd | Professional & scientific | 2026 |
| Sohajda Ltd | Transport & logistics | 2021 |
| Soho Weller Management Limited | Real estate | 2025 |
| Sohoframes Limited | Arts & recreation | 2012 |
| Solace Medical Services Ltd | Health & social care | 2026 |
| Solad Ventures Properties Ltd | Hospitality | 2017 |
| Solaha Care Limited | Health & social care | 2025 |
| Solar System Technology Limited | Construction | 2025 |
| Solaris Tanning Studio Suffolk Ltd | Other services | 2023 |
| Solavid Properties Limited | Real estate | 2019 |
| Solbay Ltd | Hospitality | 2019 |
| Solefuel Limited | Wholesale & retail | 2025 |
| Soleil Tanning Ipswich Ltd | Other services | 2020 |
| Solemn Ltd | Information & communication | 2022 |
| Solid Fuel Solutions Suffolk Limited | Administrative & support | 2024 |
| Solin Children's Homes Ltd | Health & social care | 2026 |
| Solin Supermarket Ltd | Wholesale & retail | 2016 |
| Solisana UK Limited | Wholesale & retail | 2025 |
| Solo Sessions UK Limited | Arts & recreation | 2018 |
| Solrise Studio Ltd | Wholesale & retail | 2025 |
| Solution Design Ltd | Information & communication | 2009 |
| Solution Domain Ltd | Information & communication | 2017 |
| Solution Dunn Ltd | Administrative & support | 2025 |
| Solutions 4 Group Limited | Construction | 2021 |
| Solutions 4 Properties Limited | Construction | 2018 |
| Solutions 4 Security Limited | Administrative & support | 2014 |
| Solvair Limited | Manufacturing | 2003 |
| Somersham Garage Limited | Wholesale & retail | 2003 |
| Somerville Heart Foundation | Health & social care | 2010 |
| Somner & Anders Bourne Limited | Real estate | 2015 |
| Sonesta Limited | Construction | 2014 |
| Song Estates Ltd | Real estate | 2025 |
| Songbird Survival | Other services | 2000 |
| Soni & Virdee Limited | Wholesale & retail | 2007 |
| Sonjya Urological Services Ltd | Health & social care | 2023 |
| Sonyadeya Limited | Transport & logistics | 2021 |
| Sopcho Ltd | Financial services | 2024 |
| Sophie Christiansen Limited | Arts & recreation | 2018 |
| Sophiris Limited | Professional & scientific | 2025 |
| Sophtlogic Limited | Information & communication | 1993 |
| Soprema UK Bitumen Holdings Limited | Manufacturing | 2003 |
| Soprema UK Bitumen Limited | Manufacturing | 1978 |
| Soprema UK Limited | Wholesale & retail | 1994 |
| Soprema UK Multifoils Limited | Manufacturing | 1994 |
| Soprema UK Polyiso Limited | Manufacturing | 2023 |
| Sorrel Horse Mews Management Company Limited | Real estate | 1988 |
| SOS Contracting Ltd | Construction | 2021 |
| SOS Medical Services Ltd | Health & social care | 2020 |
| Sos-Hr Limited | Professional & scientific | 2007 |
| Sostre Group Limited | Real estate | 2021 |
| Soul Salvage Community Interest Company | Arts & recreation | 2026 |
| Soul Sista Hair Ltd | Other services | 2025 |
| Sound Acoustics Ltd | Professional & scientific | 2005 |
| Sound Mind Care Solution Limited | Health & social care | 2017 |
| Sound Voice C.I.C. | Arts & recreation | 2021 |