| Saas Family Investments | Financial services | 2024 |
| Saikouworks Ltd | Manufacturing | 2026 |
| Salfar Childcare Ltd | Education | 2003 |
| Salon Equipment Centre Limited | Wholesale & retail | 1997 |
| Salta Performance Ltd | Information & communication | 2026 |
| Salus Care Services Ltd | Hospitality | 2024 |
| Salvia Properties Ltd | Real estate | 2022 |
| Sama Limited | Other services | 2008 |
| Sammario Limited | Transport & logistics | 2017 |
| Sandcastles by the Beach Limited | Real estate | 2025 |
| Sandhanum Limited | Health & social care | 2011 |
| Sandys Fishmongers Limited | Wholesale & retail | 2005 |
| Sannar Limited | Health & social care | 2012 |
| Sanroc Estates Limited | Real estate | 2019 |
| Sarah Cleaning and Care Ltd | Health & social care | 2021 |
| Saralistair Limited | Professional & scientific | 2018 |
| Sarda Ltd | Hospitality | 2019 |
| Sausage and Mash Limited | Real estate | 2023 |
| Sawston Hire Limited | | 1984 |
| SB Aviation Services Ltd | Professional & scientific | 2023 |
| SB Driving School Ltd | Education | 2023 |
| SB GH Ltd | Hospitality | 2025 |
| SBL Haulage Limited | Transport & logistics | 2018 |
| Sbvision Limited | Other services | 2010 |
| SC Support & Care Services Ltd | Health & social care | 2003 |
| Scandinavian Firewood UK Limited | Wholesale & retail | 2024 |
| Scarf Ace Limited | Wholesale & retail | 2017 |
| Scarlet Pomegranate Events Limited | Hospitality | 2025 |
| School Business Consultancy Ltd | Education | 2018 |
| Schrew Limited | Construction | 2023 |
| Scoborough Developments Limited | Construction | 2016 |
| Scot PAD Properties Ltd | Extraterritorial | 2021 |
| Scott Mccabe Associates Ltd | Construction | 2001 |
| Screenbound Entertainment Group Ltd | Information & communication | 2012 |
| Screenbound International Pictures Ltd | Information & communication | 2008 |
| Screenbound Pictures Ltd | Information & communication | 2003 |
| Screenbound Productions Limited | Extraterritorial | 2015 |
| Screenbound Releasing Limited | Extraterritorial | 2015 |
| Seafry Limited | Hospitality | 2025 |
| SECURE21 Ltd | Administrative & support | 2017 |
| SEO Partners Ltd | Professional & scientific | 2022 |
| Setary Ltd | Information & communication | 2025 |
| SEV GP LLP | | 2024 |
| SEV Group Limited | Real estate | 2020 |
| SG Display Limited | Manufacturing | 2019 |
| SGN Clothing Limited | Wholesale & retail | 2022 |
| SGW Consulting Limited | Professional & scientific | 2012 |
| Shac Consulting Ltd | Information & communication | 2011 |
| Shahid a Khan Limited | Health & social care | 2012 |
| Shalom-Torah Ltd | Other services | 2013 |
| Shaniel Transport Limited | Transport & logistics | 2016 |
| Sharnford Horticultural Limited | Manufacturing | 2002 |
| Sharnford Tractors Limited | Wholesale & retail | 1986 |
| Shaw Savage Limited | Construction | 2018 |
| Shawell Motor Cars Ltd | Wholesale & retail | 2019 |
| Shawz Ltd | Real estate | 2016 |
| Shellard Winter Management Limited | Wholesale & retail | 2004 |
| Shephard and Wilson Limited | Wholesale & retail | 1957 |
| Sherpa Family Wealth Ltd | Financial services | 2025 |
| Sherwood Kitchens Limited | Wholesale & retail | 2004 |
| Shire Leisure Ltd | Hospitality | 2025 |
| Shree RAM Krishna Limited | Wholesale & retail | 2023 |
| Shreeji IT Consultants Ltd | Administrative & support | 2016 |
| Shyams Services Ltd | Health & social care | 2019 |
| Sienkai Ltd | Professional & scientific | 2024 |
| Signature Maintenance Services Ltd. | Construction | 2019 |
| Silver Lining Project Management Limited | Professional & scientific | 2018 |
| Simbas Electrical Ltd | Construction | 2023 |
| Simden Limited | Real estate | 2018 |
| Simms Equestrian Services Limited | Financial services | 2009 |
| Simms Newsagents Ltd | Wholesale & retail | 2021 |
| Simon Tordoff Limited | Other services | 2011 |
| Simply Neuro Ltd | Other services | 2015 |
| Simpson & Co (Accountants) Ltd | Real estate | 2005 |
| Simtec Electrical Ltd | Professional & scientific | 2019 |
| Sinon Ltd | Professional & scientific | 2002 |
| Sjfprop Ltd | Real estate | 2026 |
| Skarsten Manufacturing Company Limited | Water & waste | 1939 |
| SKC Infrastructure Ltd | Professional & scientific | 2025 |
| Skin Deep Aesthetics (Hifu Clinic) Limited | Other services | 2017 |
| Skincell Clinic Ltd | Other services | 2024 |
| SKL Associates Limited | Financial services | 2024 |
| Sky View Attractions Limited | Arts & recreation | 2026 |
| Sky Wines Limited | Wholesale & retail | 2011 |
| Skyron Limited | Information & communication | 2003 |
| Sleigh Bar Ltd | Hospitality | 2025 |
| SLS Design Ltd | Construction | 2025 |
| SLS Maritime Consulting Limited | Administrative & support | 2014 |
| Smarter Security Solutions Limited | Administrative & support | 2007 |
| Smash Club Padel Limited | Hospitality | 2025 |
| Smith-Lowen Ltd | Wholesale & retail | 2025 |
| SMR Plumbing and Heating Services Ltd | Construction | 2014 |
| SN Consulting Services Ltd | Professional & scientific | 2022 |
| Snizl Holdings Limited | Information & communication | 2017 |
| Snizl Ltd | Information & communication | 2014 |
| Snowdon Red Dragon Holidays Ltd | Hospitality | 2022 |
| Softub (Midlands) Limited | Wholesale & retail | 2005 |
| Softub Services Ltd | Wholesale & retail | 2020 |
| Sohal IT Services Ltd | Information & communication | 2023 |
| Solace Consulting Ltd | Professional & scientific | 2022 |