| SD & Co Creative Ltd | Arts & recreation | 2025 |
| Second Bay Software Limited | Information & communication | 2015 |
| Second Sight CL Limited | Wholesale & retail | 1985 |
| Secreto Limited | Hospitality | 2021 |
| Secure Platform Scaffolding Ltd | Construction | 2024 |
| Secure Staff Solutions Ltd | Administrative & support | 2025 |
| Seederby Ltd | Wholesale & retail | 2012 |
| Sell ME Something Limited | Wholesale & retail | 1999 |
| Serenity Self Care and Wellbeing Ltd | Health & social care | 2019 |
| Serenity Therapy Services (NW) CIC | Health & social care | 2017 |
| Service Centre Blackburn Ltd | Wholesale & retail | 2019 |
| Seven Hills Waste Management Ltd | Water & waste | 2024 |
| Seven KC Investments Ltd | Real estate | 2020 |
| SFJ (Lancashire) Limited | Construction | 2002 |
| Shadow Wolf Properties Ltd | Financial services | 2023 |
| Shaggys Food Ltd | Hospitality | 2026 |
| Sherburn Metalwork Ltd | Extraterritorial | 2011 |
| Shield Medical Limited | Administrative & support | 2017 |
| Shims Property Management Ltd | Real estate | 2024 |
| Shine the Site Ltd | Administrative & support | 2013 |
| Shinn Thon (UK) Limited | Wholesale & retail | 2005 |
| Shipnex Limited | Extraterritorial | 2011 |
| Shirley's Recycling (Holdings) Limited | Water & waste | 2013 |
| Shirley's Recycling Limited | Water & waste | 1962 |
| Sholdy Investment Ltd | Wholesale & retail | 2018 |
| Sholdy Properties Ltd | Real estate | 2023 |
| Shopfloor Limited | Financial services | 2011 |
| Shorrocks Electrical Ltd | Construction | 2026 |
| Shrewsbury Optometry Limited | Wholesale & retail | 2008 |
| Sick Squid Ltd | Hospitality | 2023 |
| Sidney Walton Opticians Limited | Health & social care | 2007 |
| Siesta Sunbeds Limited | Administrative & support | 2012 |
| Sight Centre Limited | Wholesale & retail | 2024 |
| Silverthornes Optical Limited | Wholesale & retail | 2024 |
| Simone Robin Cooper Ltd | Extraterritorial | 2025 |
| Sincere UK Limited | Wholesale & retail | 2000 |
| SJ Webster Ltd | Real estate | 2022 |
| SJF Bollards & Barrier Solutions Limited | Construction | 2026 |
| SJF UK Group Limited | Financial services | 2023 |
| SK Projects Ltd | Professional & scientific | 2016 |
| Skilbeck & Jones (Opticians) Limited | Wholesale & retail | 1979 |
| Skinfinity Aesthetics Clinic Limited | Other services | 2021 |
| Skippys Event Services Limited | Manufacturing | 2019 |
| Sky NW Holdings Limited | Real estate | 2026 |
| Skye Optometrists Limited | Health & social care | 2012 |
| Slrcw Engineering and Mechanical Fitter Limited | Professional & scientific | 2025 |
| Smajer Legal Consulting Ltd | Professional & scientific | 2026 |
| Smajid Optical Ltd | Health & social care | 2019 |
| Smart Aerials Ltd | Construction | 2022 |
| Smart Energy Networks Limited | Professional & scientific | 2010 |
| Smart EVC Ltd | Extraterritorial | 2022 |
| Smarter Energy UK Ltd | Wholesale & retail | 2020 |
| Smartsun Limited | Real estate | 1999 |
| SME Safety Solutions Limited | Professional & scientific | 2012 |
| Smewing Optical Services Limited | Health & social care | 2006 |
| Smith & Butterfield Limited | Wholesale & retail | 2012 |
| SMJ Foods Ltd | Hospitality | 2024 |
| SMJ Future Limited | Financial services | 2023 |
| SMJ Investments Ltd | Financial services | 2023 |
| SMORGAN47 Ltd | Hospitality | 2015 |
| SMS Delivery Limited | Information & communication | 2024 |
| Smyth & SON Engineering Ltd | Manufacturing | 2017 |
| SN Electrical Services Ltd | Construction | 2018 |
| Snatch Property Investments Ltd | Real estate | 2023 |
| Snazzys School Wear Ltd | Wholesale & retail | 2023 |
| Soilsafe Ltd | Water & waste | 2020 |
| Sole Cafe Ltd | Wholesale & retail | 2019 |
| Solids & Powder Handling Limited | Manufacturing | 2014 |
| Solis Services Limited | Wholesale & retail | 2017 |
| Solitaire Fashions Limited | Wholesale & retail | 2011 |
| Sonic Basics Ltd | Hospitality | 2018 |
| Sonoview Diagnostics Ltd | Health & social care | 2017 |
| SOS Laminators Limited | Manufacturing | 2009 |
| Sound Clear Audiology Limited | Wholesale & retail | 2024 |
| Source Dental Laboratory Ltd | Manufacturing | 2017 |
| South Cheshire Driveways Ltd | Construction | 2024 |
| South Downs Hearing Limited | Wholesale & retail | 2021 |
| Sparks HR Consultancy Ltd | Professional & scientific | 2023 |
| Specs of Kensington Limited | Wholesale & retail | 2008 |
| Spectacle Solutions Ltd. | Administrative & support | 2003 |
| Spectrum Telecomms and Construction Ltd | Information & communication | 2023 |
| Spencer's Marketing Ltd | Professional & scientific | 2024 |
| Spengler's Limited | Manufacturing | 2023 |
| Spice Darwen Limited | Hospitality | 2025 |
| Spindles Diner Ltd | Hospitality | 2019 |
| Spinks Speks Limited | Wholesale & retail | 1996 |
| Spiroflow Limited | Manufacturing | 1975 |
| Spitfire FUN Vault Ltd | Hospitality | 2025 |
| Sporting NRG Limited | Arts & recreation | 2010 |
| Spotless Surfaces Ltd | Administrative & support | 2014 |
| Springertopia Ltd | Information & communication | 2025 |
| Springside Investments Limited | Hospitality | 2001 |
| Spyrian Engineering Ltd | Professional & scientific | 2024 |
| Square Deal Window Co. Limited(The) | Administrative & support | 1976 |
| SR Metal Trading Ltd | Wholesale & retail | 2025 |
| SSI Holdings Group Ltd | Financial services | 2025 |
| SSI Home Limited | Wholesale & retail | 2016 |
| Ssld Healthcare Ltd | Wholesale & retail | 2011 |
| SSS Industrial Doors Ltd | Construction | 2011 |
| ST. Michael’S Gardens Management Company Limited | Households | 2021 |