| Service 87 Limited | Other services | 2001 |
| SG Heating & Plumbing Ltd | Construction | 2011 |
| Sgrove WF LLP | | 2022 |
| Sgsworks Ltd | Extraterritorial | 2024 |
| SGW Bayne JV5 LLP | | 2016 |
| Shadow Wall Limited | Construction | 2013 |
| Shamraeff Consulting Limited | Financial services | 2008 |
| Shanwin Property Services Limited | Construction | 2018 |
| Shaw Hydraulics Limited | Manufacturing | 1998 |
| Sheen Stickland Audit Limited | Professional & scientific | 1988 |
| Sheen Stickland LLP | | 2005 |
| Sheraton & Co Ltd | Professional & scientific | 2014 |
| Sherewood Property Management Limited | Real estate | 2022 |
| Sheron Limited | Wholesale & retail | 2002 |
| Shibumi Partners Limited | Hospitality | 2016 |
| Shires Advisory Limited | Professional & scientific | 2023 |
| Shirlaw Homes Limited | Wholesale & retail | 2017 |
| SHL Property Management Limited | Real estate | 2013 |
| Shoreditch (T) Hairdressing Limited | Other services | 2020 |
| Short Message Services Limited | Professional & scientific | 2001 |
| Showshack Performing Arts Ltd | Education | 2023 |
| Shrewsbury (T2) Hairdressing Limited | Other services | 2020 |
| Shrewsbury (T3) Hairdressing Limited | Other services | 2024 |
| Sibert Instruments Limited | Manufacturing | 1987 |
| Sidecog Limited | Information & communication | 2026 |
| Sigmon Technologies Ltd | Administrative & support | 2020 |
| Silchester Control Systems Limited | Professional & scientific | 1993 |
| Silk & Waves Limited | Wholesale & retail | 2018 |
| Silvarow Holdings Limited | Administrative & support | 2017 |
| Silverback Carpentry and Joinery Ltd | Manufacturing | 2023 |
| Silverback Consultants International Limited | Professional & scientific | 2023 |
| Silverdene Homes Limited | Construction | 1985 |
| Simon Burwood Limited | Information & communication | 2010 |
| Simon Crane Associates Limited | Real estate | 2015 |
| Simon's Stores Limited | Wholesale & retail | 2020 |
| Simon's Stores Property Holding Company Ltd | Financial services | 2022 |
| Simply Chesterfields Ltd | Wholesale & retail | 2022 |
| Simply Energy Ltd | Information & communication | 2021 |
| Simply Life & Mortgages Ltd | Financial services | 2015 |
| Sims UAV LLP | | 2020 |
| Single Steps Nurseries Liss Ltd | Health & social care | 2024 |
| Single Steps Nurseries Ltd | Health & social care | 2019 |
| Sirah Solutions Limited | Professional & scientific | 2021 |
| Site Services Security Limited | Manufacturing | 2006 |
| Sitestak Limited | Administrative & support | 2018 |
| SJ Mather Limited | Administrative & support | 2009 |
| SJ Pearson Consulting Ltd | Information & communication | 2014 |
| SJP Auto Locks Limited | Wholesale & retail | 2025 |
| Skomer Holdings Limited | Financial services | 2026 |
| Sky View Solutions Ltd | Information & communication | 2020 |
| Skycroft Services Ltd | Administrative & support | 2025 |
| Skyfall Home Improvements Limited | Wholesale & retail | 2017 |
| Skyren Consulting Ltd | Professional & scientific | 2026 |
| Slac Holdings Ltd | Financial services | 2023 |
| Slac Precision Engineering Ltd | Manufacturing | 2018 |
| Sleepless Apparel Limited | Wholesale & retail | 2021 |
| Slick Boys Limited | Wholesale & retail | 2015 |
| Slickcut Limited | Other services | 2019 |
| Sloane Square (T) Hairdressing Limited | Other services | 2020 |
| Slush Truck Ltd | Hospitality | 2021 |
| Slush Truck Retail Ltd | Wholesale & retail | 2023 |
| SM Bidco Ltd | Financial services | 2025 |
| Smarties SPV Ltd | Information & communication | 2024 |
| Smartstay Hotels Limited | Hospitality | 2023 |
| Smokeyburgers Limited | Hospitality | 2024 |
| Snook Events Company Limited | Administrative & support | 2007 |
| Soccer Schools UK Limited | Arts & recreation | 2016 |
| Social Coco Ltd | Professional & scientific | 2021 |
| Societe Limited | Administrative & support | 2003 |
| Softbits Consultants Limited | Information & communication | 1987 |
| SOL N' Shine Ltd | Manufacturing | 2025 |
| Solare Consulting Ltd | Information & communication | 2025 |
| Sole Removals Ltd | Transport & logistics | 2025 |
| Sole Sporting Limited | Arts & recreation | 2018 |
| Solent Reach Properties Ltd | Real estate | 2026 |
| Solentsoft Ltd. | Information & communication | 2007 |
| Solihull (T) Hairdressing Limited | Other services | 2010 |
| Solo Tyres Limited | Wholesale & retail | 2000 |
| Solstice Energy Limited | Construction | 2003 |
| Sophie Lorraine Natural Living Ltd | Wholesale & retail | 2026 |
| Sorrel Safety Ltd | Professional & scientific | 2026 |
| South Coast Saddlery Limited | Arts & recreation | 2016 |
| South Downs Developments Limited | Construction | 2018 |
| South East Multi Services Ltd | Construction | 2023 |
| South Woodford (T) Hairdressing Limited | Other services | 2001 |
| Southampton (T) Hairdressing Limited | Other services | 2007 |
| Southdown Aero Services Limited | Manufacturing | 1962 |
| Southdown Aerospace Services Ltd | Manufacturing | 2024 |
| Southdown Composites Ltd. | Administrative & support | 1987 |
| Southend (T) Hairdressing Limited | Other services | 2008 |
| Southern Aero Supplies Ltd | Wholesale & retail | 2023 |
| Southern Area Solutions Drainage and Groundwork Limited | Construction | 2019 |
| Southern Demolition Company Limited | Construction | 1959 |
| Southern Demolition Consultancy Limited | Construction | 2002 |
| Southern Demolition Trustees Limited | Professional & scientific | 2025 |
| Southern Flooring & Design Limited | Construction | 2023 |
| Southern Recycling Company Limited | Extraterritorial | 2007 |
| Southern Temperature Sensors Limited | Wholesale & retail | 2000 |
| Spa Soft Ltd. | Information & communication | 2007 |
| Spatial Creative Ltd | Information & communication | 2025 |