| Skywalk Properties Ltd | Real estate | 2024 |
| SL Print Supplies Ltd | Manufacturing | 2013 |
| Sl-Ehsply Ltd | Professional & scientific | 2022 |
| Slano Ltd | Wholesale & retail | 2025 |
| Sleeping Dog Trading Ltd | Wholesale & retail | 2016 |
| Slip Audley I LLP | | 2023 |
| Slip Audley II LLP | | 2023 |
| Slipstream Consulting Limited | Information & communication | 2009 |
| Sloth Games Ltd | Information & communication | 2025 |
| Slowflow Ltd | Real estate | 2025 |
| SM Financial Ltd | Financial services | 2015 |
| SM Sunshine Media Ltd | Professional & scientific | 2022 |
| Small Business Accounts and Advisory Service Limited | Professional & scientific | 2002 |
| Smart Start Oldham Limited | Education | 2019 |
| Smart Wire Ltd | Construction | 2018 |
| Smarta Method Ltd | Health & social care | 2023 |
| SME Media UK Limited | Information & communication | 2013 |
| Smeets Ltd | Financial services | 2025 |
| Smiths (Englefield Green) Limited | Wholesale & retail | 1961 |
| SMS SET UP Ltd | Professional & scientific | 2024 |
| SMV Services Ltd | Wholesale & retail | 2017 |
| SN London Collections Ltd | Wholesale & retail | 2026 |
| Snapper Consulting Limited | Professional & scientific | 2015 |
| Snow IT Ltd | Information & communication | 2024 |
| SNS High Voltage Engineering Ltd | Professional & scientific | 2021 |
| Social Care Institute for Excellence | Health & social care | 2001 |
| Socialis ET Scientia Ltd | Other services | 2025 |
| Sofia Education & Animals Ltd | Financial services | 2021 |
| Soft Work International Ltd | Other services | 2024 |
| Soiltec International Limited | Extraterritorial | 2006 |
| SOL Electrical and Lighting Ltd | Wholesale & retail | 2025 |
| Solaia.R.E Limited | Real estate | 2013 |
| Solar Real Invest Ltd | Financial services | 2021 |
| Solid Anchor Ltd | Real estate | 2023 |
| Solihull Land Holdings Limited | Financial services | 2022 |
| Solmero Limited | Wholesale & retail | 2025 |
| SOM International Ltd | Education | 2023 |
| Sonbeam Limited | Hospitality | 2023 |
| Songkarn Limited | Wholesale & retail | 1978 |
| Sound of Rushing Waters Ltd | Financial services | 2020 |
| South West Garden Centres Limited | Wholesale & retail | 2019 |
| Southeast UK Management Limited | Professional & scientific | 2021 |
| Southern Counties Care Limited | Health & social care | 1988 |
| Southern Pizza Ltd | Hospitality | 2026 |
| Southpants Ltd | Real estate | 2026 |
| Sovereign (George Potter) Limited | Health & social care | 1999 |
| Sovereign (the Laurels) Limited | Health & social care | 1999 |
| Space Compass Ltd | Financial services | 2021 |
| Space of Hearts Ltd | Real estate | 2023 |
| Sparkle Sisters Surrey Ltd | Administrative & support | 2021 |
| Spartakus Ltd | Construction | 2014 |
| Special Situations China Ltd | Professional & scientific | 2015 |
| Spectare Limited | Professional & scientific | 2018 |
| SPG Education Ltd | Education | 2014 |
| Spice Cupboard Ltd | Wholesale & retail | 2024 |
| SPL Roofing Services Ltd | Construction | 2019 |
| Springhill Advisory Limited | Professional & scientific | 2013 |
| Springtime Living Ltd | Financial services | 2019 |
| SPU Invest Ltd | Financial services | 2021 |
| Squaret Properties Ltd | Real estate | 2022 |
| Squirrate Ltd | Education | 2024 |
| SRS Carpentry Limited | Construction | 2007 |
| Sshpro Limited | Information & communication | 2021 |
| Ssjm Holdings Limited | Real estate | 2022 |
| ST Agnes Cottages Freehold Limited | Households | 2005 |
| ST Catherines Place Freehold Co Ltd | Households | 2013 |
| ST George Development Property Ltd | Real estate | 2017 |
| ST George Pharma UK Limited | Professional & scientific | 2013 |
| ST George Retail Ltd | Wholesale & retail | 2017 |
| ST Mary LE Park Freehold Limited | Households | 2000 |
| ST. Dominic's Ltd. | Health & social care | 1989 |
| Stafford Care Home Holdings Limited | Financial services | 2019 |
| Stafford Care Home Limited | Real estate | 2019 |
| Stafford Care Limited | Health & social care | 2019 |
| Stam Property Ltd | Real estate | 2021 |
| Staplewood Hurst Lane Limited | Construction | 2017 |
| STAR53 Ltd | Administrative & support | 2025 |
| Stardust Trade Limited | Wholesale & retail | 2024 |
| Starlight Shine Limited | Other services | 2024 |
| Starlight Strive Limited | Other services | 2024 |
| Staying Power Investments Ltd | Hospitality | 2021 |
| Stbs Solutions Ltd | Construction | 2020 |
| Stefanahealth Ltd | Health & social care | 2025 |
| Stein Seal UK Ltd | Wholesale & retail | 2001 |
| Stellar Edge Enterprises Limited | Wholesale & retail | 2024 |
| Stellar Ice AGE LLP | | 2025 |
| Stellar Moon Events Limited | Other services | 2024 |
| Steltenpool Real Estate Ltd | Real estate | 2024 |
| Sterretje Ltd | Real estate | 2022 |
| Steuern MIT System Limited | Professional & scientific | 2023 |
| Stewart’S Scaffolding and Rigging Ltd | Construction | 2023 |
| Stiftung Fuer Glaube, Hoffnung UND Hilfe Ltd | Other services | 2025 |
| Stokes Chiropractic Ltd | Construction | 2023 |
| Stonecreek Developments Ltd | Construction | 2023 |
| Stonegb Ltd | Real estate | 2023 |
| Stonehill Property Investments Ltd | Real estate | 2025 |
| Stooltool Limited | Information & communication | 2025 |
| Stopinsidercrime Ltd | Professional & scientific | 2026 |
| Stopinsiderfraud Limited | Professional & scientific | 2026 |
| Storm Care | Health & social care | 2021 |