| Select Support Partnerships Ltd | Health & social care | 2002 |
| Sensing Devices Limited | Manufacturing | 1971 |
| Seven Energy Services Limited | Construction | 2019 |
| Seven L (GB) Ltd | Administrative & support | 2004 |
| Seville Greenwood Limited | Construction | 1972 |
| Seymour Green Management Company Limited | Real estate | 2005 |
| Sgas Northern Ireland Ltd | Administrative & support | 2003 |
| SGS Joinery Limited | Construction | 2003 |
| Shaahi Selection Ltd | Wholesale & retail | 2025 |
| Shah Joli Takeaway Ltd | Hospitality | 2025 |
| Shandar Sweets Ltd | Wholesale & retail | 2005 |
| Shanghai Import UK Limited | Wholesale & retail | 2006 |
| Shannons Properties Limited | Real estate | 1951 |
| Shape International Limited | Professional & scientific | 1999 |
| Sharper Hair Design Limited | Administrative & support | 2007 |
| Shaun Francis Roofing Limited | Construction | 2006 |
| Shaw Maintenance Limited | Construction | 2003 |
| Shearers Gents Hair Design Limited | Other services | 2003 |
| Shirley MAY Distributors Limited | Wholesale & retail | 1981 |
| Shortpace Limited | | 1987 |
| Shotstoppers Limited | Administrative & support | 2007 |
| Showtime Icerinks Limited | Arts & recreation | 2005 |
| SHP Valuers Limited | Administrative & support | 2003 |
| Shree Hari UK Limited | Administrative & support | 2006 |
| Signal Lite Limited | Professional & scientific | 2002 |
| Silect Chemicals Limited | Professional & scientific | 1990 |
| Silkwood Property Management Company Limited | Real estate | 2001 |
| Silmed Limited | Administrative & support | 2014 |
| Silver Fish Supply Limited | Wholesale & retail | 1996 |
| Silverturn Limited | Construction | 2007 |
| Simart Company Ltd | Construction | 2019 |
| Simmo Developments Limited | Construction | 2006 |
| Simon Browning Optical Ltd | Wholesale & retail | 2018 |
| Simon Gillespie Associates Ltd | Professional & scientific | 2000 |
| Simply the Best (Whalley) Limited | Other services | 2004 |
| Sincotech Limited | Information & communication | 2003 |
| Siqayah Ltd | Financial services | 2021 |
| Sissors Limited | Other services | 2002 |
| Site Surveying Limited | Construction | 1999 |
| Sitecom 2000 Ltd | Construction | 2002 |
| Sixteenseventeen Limited | Professional & scientific | 2005 |
| SJ and K Brown Limited | Wholesale & retail | 2003 |
| Skelmersdale Metal Treatment Ltd | Construction | 2004 |
| Skem Express Cars Ltd. | Transport & logistics | 1989 |
| Skin & Bones Medical Limited | Health & social care | 2023 |
| Skin Fantasy Limited | Other services | 2002 |
| Sky High Holdings Limited | Real estate | 2022 |
| Skytech Medical Limited | Professional & scientific | 2006 |
| SL Care Solutions Limited | Health & social care | 2025 |
| Sling (U.K.) Limited | Wholesale & retail | 2003 |
| Smartweld Engineering Ltd | Professional & scientific | 2025 |
| Smartypants Exclusive Childcare Limited | Education | 2007 |
| Smiles of Confidence Limited | Other services | 2002 |
| SML Home Improvements Limited | Construction | 2007 |
| SMT Superbikes Ltd | Other services | 2007 |
| Snapfly Limited | Financial services | 2007 |
| Snappydeals Limited | Wholesale & retail | 2000 |
| Snowdrop Housing Limited | Real estate | 2006 |
| Soft Sell Group Limited | Information & communication | 2002 |
| Software by Firth Limited | Administrative & support | 2001 |
| Solonian Limited | Information & communication | 2007 |
| Solutions for Business Limited | Information & communication | 2003 |
| Songsmith Records Limited | Arts & recreation | 2000 |
| Sonix Construction Limited | Construction | 2007 |
| Sound Social Care Limited | Health & social care | 2009 |
| Sourbridge Public House Limited | Hospitality | 2024 |
| Sourcing Partners Trading Limited | Construction | 2023 |
| Sourville Ltd | Professional & scientific | 2007 |
| South Bank Management Company (1994) Limited | Households | 1994 |
| Sovereign Aluminium Frames Limited | Manufacturing | 2003 |
| Sovereign Logistics & Distribution Limited | Transport & logistics | 2003 |
| Spaans Babcock Limited | Manufacturing | 1992 |
| Sparkles Cakes and Wedding Accessories Limited | Manufacturing | 2005 |
| Sparkles Property Cleaning Services Ltd | Administrative & support | 2022 |
| Speakeasy Publishing Ltd | Education | 2005 |
| Specialised Surface Coatings Limited | Manufacturing | 1995 |
| Specialist UK Restorations Limited | Construction | 2005 |
| Spectral Colours Limited | Manufacturing | 1991 |
| Spenlow Window Systems Limited | Construction | 2001 |
| Spinneycrest Limited | Professional & scientific | 1995 |
| Spotland Community Association | Health & social care | 1988 |
| Springhill Hospice (Lottery) Limited | Arts & recreation | 1997 |
| Springside Building Services Limited | Construction | 2003 |
| Springwell Walker Ltd | Wholesale & retail | 2025 |
| SPS Geotech Systems Limited | Manufacturing | 2007 |
| SPS Marsland Limited | Construction | 2007 |
| ST Anthony's Parish Centre Limited | Other services | 1997 |
| ST Investments Group Limited | Financial services | 2025 |
| ST Lukes (Lancaster) Limited | Households | 1997 |
| ST. Anne's & ST. Joseph's OUT of School Club | Education | 2008 |
| ST. George Glass Company (Bury) Limited | Manufacturing | 1958 |
| ST. Ives Hotel Limited | Hospitality | 1993 |
| Stage Properties Ltd | Real estate | 2003 |
| Stage Solutions Limited | Wholesale & retail | 2003 |
| Standfirm Properties Limited | Real estate | 1995 |
| Standish Mortgage Services Ltd | Financial services | 2003 |
| Stanley Court Management Company Limited | Households | 1991 |
| Stanton Andrews Limited | Professional & scientific | 2006 |
| Starlight Bedrooms Limited | Manufacturing | 2003 |
| Startfit Limited | Wholesale & retail | 1989 |