| S.Decor Ltd | Construction | 2016 |
| S.E Homes Worldwide Ltd | Real estate | 2018 |
| S.F.F. Utilities Limited | Construction | 2006 |
| S.J. LEE Consulting Limited | Professional & scientific | 2010 |
| S.M. Drilling Consultants Limited | Professional & scientific | 1989 |
| S2B Works Ltd | Construction | 2026 |
| SA Marketplace Ltd | Wholesale & retail | 2025 |
| SA Taylor Construction Limited | Construction | 2015 |
| Saan Technologies Limited | Information & communication | 2009 |
| Saasphr Ltd | Information & communication | 2024 |
| Sable Cottage Limited | Health & social care | 2009 |
| Sabr Digital Ltd | Information & communication | 2009 |
| Sabr Property Care Ltd | Construction | 2025 |
| Sabre Resource Management Limited | Administrative & support | 2003 |
| Sackville Mews (Sutton) Management Limited | Households | 1987 |
| Sade Stylists Limited | Other services | 2016 |
| Sadr Consulting Ltd | Information & communication | 2026 |
| Safe Circle Transport Ltd | Transport & logistics | 2026 |
| Safe-Electric (Nationwide) Ltd | Construction | 2011 |
| Sage Boutique Ltd | Other services | 2020 |
| Sahiwal Consultancy Ltd | Real estate | 2011 |
| Saibright Limited | Information & communication | 2011 |
| Saikyo Holdings Limited | Households | 2024 |
| Sailscape Limited | Hospitality | 2023 |
| Saint John Chandler Limited | Construction | 2024 |
| Sala Medical Limited | Health & social care | 2013 |
| Saleha Majid Ltd | Real estate | 2019 |
| Sales Made Easy Limited | Professional & scientific | 2020 |
| Salina Design Company Limited | Professional & scientific | 2017 |
| Salio Consulting Limited | Extraterritorial | 2020 |
| Sallhill Properties Limited | Administrative & support | 2013 |
| Salonis Hair Limited | Other services | 2017 |
| Salt & Boabab Ltd | Professional & scientific | 2026 |
| Saltwater Crocodile Ventures Ltd | Professional & scientific | 2026 |
| Salty Dog Limited | Hospitality | 2024 |
| Salvatunes Limited | Transport & logistics | 2026 |
| SAM Kopsch Studio Limited | Professional & scientific | 2012 |
| Sampatee Ltd | Information & communication | 2022 |
| Samson Site Services Limited | Construction | 2009 |
| Sanchos Grill Ltd | Hospitality | 2022 |
| Sandars Maltings Management Company Limited | Households | 2012 |
| Sandbar Holdings Limited | Financial services | 2024 |
| Sandgate Flats Limited | Households | 1956 |
| Sandhu Contractor Limited | Construction | 2018 |
| Sandore UK Ltd | Professional & scientific | 2025 |
| Sandra Steer Marketing Ltd | Professional & scientific | 2011 |
| Sanger Analytics Limited | Information & communication | 2015 |
| Sansovino Limited | Professional & scientific | 2011 |
| Santiago Consultancy Ltd | Professional & scientific | 2018 |
| Santprado Aesthetic Ltd | Health & social care | 2026 |
| SAO Associates Limited | Professional & scientific | 2019 |
| Saoc Accounting Ltd | Professional & scientific | 2025 |
| Sapphire Contractors Limited | Other services | 1982 |
| Sapphire Tooling Limited | Extraterritorial | 2025 |
| Saqa Consultancy Limited | Administrative & support | 2017 |
| Sara Consultants Limited | Information & communication | 2011 |
| Sarah Homeland Management Ltd | Real estate | 2025 |
| Sarah Krebietke Ltd | Professional & scientific | 2026 |
| Sartorius Stedim UK Limited | Wholesale & retail | 2006 |
| Sartorius UK Limited | Wholesale & retail | 1973 |
| SAS Drywall Ltd | Construction | 2019 |
| Sash Window Wizard Ltd | Construction | 2019 |
| Sasmata Joynery Solution Ltd | Manufacturing | 2019 |
| Satyanpatelpodiatry Limited | Health & social care | 2025 |
| Saunders Footwear Limited | Real estate | 1949 |
| Sausas Ltd | Wholesale & retail | 2025 |
| Savill Properties Limited | Real estate | 2015 |
| Saville Family Investments Limited | Financial services | 2022 |
| Savings Sourced Limited | Wholesale & retail | 2011 |
| Savoa Limited | Hospitality | 2025 |
| Saxon Court Limited | Households | 2009 |
| Saxon UK Developments Ltd | Real estate | 2013 |
| Saxonbury Limited | Professional & scientific | 1984 |
| Saxwood Properties Limited | Real estate | 2014 |
| Sayan Cosmetic Limited | Wholesale & retail | 2025 |
| SBC EOT Ltd | Professional & scientific | 2023 |
| SC Heating Controls Ltd | Manufacturing | 2022 |
| Scale OR Sell Advisory Ltd | Information & communication | 2025 |
| Scaleclear Limited | Professional & scientific | 2025 |
| Scaleops Search Ltd | Information & communication | 2025 |
| Scarlet Arrow Limited | Real estate | 2024 |
| Scarlett's Boutique Limited | Manufacturing | 2026 |
| SCE Associates Limited | Professional & scientific | 2024 |
| Scentscentral Ltd | Information & communication | 2025 |
| School Lane Investments Limited | Households | 1973 |
| School's Outreach Service Ltd | Professional & scientific | 2014 |
| Schools MIS Limited | Education | 2023 |
| Scott & Twine Interiors Limited | Professional & scientific | 2013 |
| Scott & Twine LLP | | 2012 |
| Scott Shields Music Ltd | Information & communication | 2014 |
| Scouted Minds Ltd | Administrative & support | 2021 |
| Script Checker Limited | Public administration | 2022 |
| SCT Consultancy Limited | Administrative & support | 2024 |
| Sculpted Gardens Limited | Administrative & support | 2025 |
| SCV Electrical Limited | Construction | 2013 |
| SCV Properties Ltd | Real estate | 2021 |
| SD & R Property Services Ltd | Real estate | 2021 |
| SD Sons Ltd | Other services | 2020 |
| SDC Mobile Ltd | Administrative & support | 2020 |
| Sdgc Limited | Arts & recreation | 2022 |