| Smart Animal Welfare Ltd | Professional & scientific | 2022 |
| Smart Autobody Repairs Ltd | Transport & logistics | 2024 |
| Smart Online Accounting Limited | Extraterritorial | 2012 |
| Smart Origin Group Ltd | Manufacturing | 2026 |
| Smash & Shake Birkenhead Limited | Hospitality | 2024 |
| Smash N Sizzle Wrexham Limited | Hospitality | 2025 |
| Smash Port Ltd | Hospitality | 2026 |
| Smash ‘N’ Sizzle Buckley PVT Ltd | Hospitality | 2025 |
| SMD Clinics Ltd | Administrative & support | 2020 |
| SME Water Ltd | Administrative & support | 2018 |
| SMG Electrical and Security Ltd | Construction | 2020 |
| Smhsn Limited | Hospitality | 2021 |
| Smile Design LAB Ltd | Health & social care | 2018 |
| Smile Link Dental Limited | Health & social care | 2024 |
| Smile Oasis (Bradford) Ltd | Health & social care | 2025 |
| Smile Oasis (Leeds) Ltd | Health & social care | 2025 |
| Smile Oasis (Ripon) Ltd | Health & social care | 2025 |
| Smile Oasis Limited | Health & social care | 2024 |
| Smiles by Paula Ltd | Health & social care | 2023 |
| Smiles by Shubham Limited | Health & social care | 2016 |
| Smiles Services Limited | Health & social care | 2023 |
| Smilesbykavitha Limited | Health & social care | 2023 |
| Smith Brothers Renovation Ltd | Construction | 2025 |
| Smiths Cabinets and Joinery Ltd | Manufacturing | 2012 |
| Smithy Lane Management Limited | Households | 2016 |
| Smps 2012 Limited | Wholesale & retail | 2021 |
| Sndent Limited | Health & social care | 2025 |
| Sneakers Classified Ltd | Transport & logistics | 2019 |
| Snelson Consulting Limited | Professional & scientific | 2023 |
| SNS Competitions Ltd | Wholesale & retail | 2023 |
| Sofgab Investments Limited | Financial services | 2025 |
| Soft Launch Limited | Wholesale & retail | 2021 |
| Solis Studio Ltd | Health & social care | 2024 |
| Solomon Lifting Solutions Limited | Construction | 2025 |
| Solution Based Services Ltd | Professional & scientific | 2019 |
| Solutions Asset Finance Limited | Financial services | 2006 |
| Solutions Corporate Trustee Limited | Professional & scientific | 2022 |
| Solutions in Service Ltd | Health & social care | 2013 |
| Solutions Topco Limited | Professional & scientific | 2017 |
| Solve C Ward Limited | Financial services | 2017 |
| Songwriters International Ltd | Education | 2019 |
| Sophie Foster Psychological Services Limited | Health & social care | 2025 |
| Sound-Train Ltd | Education | 2023 |
| SOURCE4 Solutions Ltd | Information & communication | 2002 |
| Sovereign Solutions Ltd | Health & social care | 2024 |
| SP Support Services Ltd | Administrative & support | 2017 |
| SP3 Limited | Hospitality | 2003 |
| Spanish Ositos Limited | Education | 2026 |
| SPARES2GO Retail Limited | Professional & scientific | 2013 |
| Sparesworks Limited | Wholesale & retail | 2015 |
| Sparklepro Group Limited | Construction | 2025 |
| Sparks Dental Ltd | Health & social care | 2023 |
| Spartan KG Limited | Real estate | 2023 |
| Speak to Shine Limited | Professional & scientific | 2020 |
| Specialist Weight Loss Company Limited | Health & social care | 2020 |
| Speedodeals Ltd | Wholesale & retail | 2024 |
| Speedy Transport Logistic Ltd | Transport & logistics | 2026 |
| SPH Actuarial Services Limited | Financial services | 2010 |
| Spice N Smoke Wrexham Ltd | Hospitality | 2025 |
| Spiderwort Limited | Real estate | 2024 |
| Spirit Cars Ltd | Administrative & support | 2024 |
| SPM Installations Limited | Manufacturing | 2020 |
| Sports Xtra (Franchising) Limited | Education | 2008 |
| Sprout Kitchen Garden Limited | Hospitality | 2021 |
| Spyder CRM LLP | | 2024 |
| SRB Dental Ltd | Health & social care | 2023 |
| Srdc Limited | Health & social care | 2015 |
| Srdc Property Limited | Administrative & support | 2017 |
| Srenim Management Company Limited | Households | 2003 |
| SRG SON Transport Ltd | Transport & logistics | 2019 |
| Srls Properties Ltd | Real estate | 2025 |
| Srsr Development Ltd | Other services | 2022 |
| SSE Site Services Limited | Administrative & support | 2003 |
| SSI Medical Services Ltd | Health & social care | 2024 |
| ST Margarets Dental Ltd | Health & social care | 2024 |
| ST. Johns Terrace (Keswick) Management Company Limited | Professional & scientific | 1993 |
| Stableford (Worcester) Management Company Limited | Households | 2019 |
| Staingard BFB Ltd | Administrative & support | 2025 |
| Staingard Protect Europe Ltd | Administrative & support | 2026 |
| Staingard Protect Ltd | Administrative & support | 2025 |
| Staingard SFL Ltd | Administrative & support | 2025 |
| Staingard Warranty Management Limited | Professional & scientific | 2025 |
| Stamford Bridge Dental Ltd | Health & social care | 2012 |
| Stamford Village Store Limited | Real estate | 2003 |
| Stanlaw Abbey Development Trust Ltd | Other services | 2005 |
| Stanley Recruitment Limited | Administrative & support | 1973 |
| Stanlow Commercial Vehicles Ltd | Wholesale & retail | 2024 |
| Stanlow Pallets Limited | Wholesale & retail | 1999 |
| Stanlow Terminals Limited | Manufacturing | 2018 |
| Star DEV Training Ltd | Professional & scientific | 2018 |
| Stark Athletic Apparel Limited | Arts & recreation | 2020 |
| Stark Dental Ltd | Health & social care | 2024 |
| Starkives Ltd | Arts & recreation | 2025 |
| Starling Enterprises Ltd | Manufacturing | 2010 |
| Starlite Holdings Ltd | Health & social care | 2024 |
| Start Right Apprenticeships Ltd | Education | 2026 |
| Status Security Ltd | Administrative & support | 2022 |
| Stcc Turker Consulting Limited | Manufacturing | 2020 |
| Steele Burtenshaw Properties Ltd | Real estate | 2025 |
| Steelix Ltd | Manufacturing | 2025 |