| Savant Future Limited | Education | 2022 |
| Savernake Maintenance Company Limited | Professional & scientific | 2000 |
| Savnik Solutions Ltd | Wholesale & retail | 2018 |
| Savvy Ecom Ltd | Wholesale & retail | 2025 |
| Savvy Tech Gadgets Ltd | Wholesale & retail | 2026 |
| Sawgrass Property Investments Limited | Real estate | 1997 |
| Sawusbah Company Limited | Wholesale & retail | 2022 |
| Saya Yachting Ltd | Extraterritorial | 2024 |
| SAZ M Limited | Financial services | 2013 |
| SB Bromley Ltd | Hospitality | 2024 |
| SB Plastering & Rendering Limited | Construction | 2020 |
| SB Squared Consulting Limited | Financial services | 2018 |
| SBR Advisory Limited | Professional & scientific | 2026 |
| Sbrolly Ltd | Information & communication | 2025 |
| SC A2 Limited | Real estate | 2025 |
| Scadeng Ltd | Professional & scientific | 2007 |
| Scaleability Services Ltd | Professional & scientific | 2020 |
| Scanel Green Energy Limited | Professional & scientific | 2023 |
| Scansky Engineering Ltd | Construction | 2015 |
| Scar Sky Trading Limited | Wholesale & retail | 2025 |
| Scarab Consulting Limited | Information & communication | 2010 |
| Scarecrow Ltd | Professional & scientific | 2009 |
| Scaredy Cat Productions Ltd | Information & communication | 2023 |
| Scatterbrain Studios Ltd | Arts & recreation | 2021 |
| Scbp Holdings Limited | Financial services | 2022 |
| SCC Electrical Services Ltd | Construction | 2019 |
| Scentsandsamples Ltd | Other services | 2024 |
| Schishi Medical Ltd | Health & social care | 2021 |
| Schmattes Ltd | Professional & scientific | 2018 |
| Schmitt Brookes Design Limited | Arts & recreation | 2011 |
| Scholarly Film Company Ltd | Information & communication | 2019 |
| Schoolhouse (Pages Walk) Management Company Limited | Households | 1994 |
| SCL Talk Ltd | Health & social care | 2025 |
| SCM Plumbing & Drainage Ltd | Construction | 2023 |
| Scoops Desserts & Shakes Ltd | Hospitality | 2026 |
| Scoresdale Management Limited | Households | 1986 |
| Scoresdale Residents Unite Limited | Households | 2012 |
| Scorpio Wine House Limited | Hospitality | 2018 |
| Scorpion Barbers and Supplies Limited | Wholesale & retail | 2024 |
| Scott Wakeford Limited | Professional & scientific | 2025 |
| Scott-Free Property Ltd | Households | 2018 |
| Scotts Access Scaffolding Ltd | Construction | 2019 |
| Scriven TEN RTM Company Limited | Households | 2023 |
| Scrubs Strategic Limited | Real estate | 2018 |
| Scrummymunchies Limited | Manufacturing | 2011 |
| Scrypt Capital Limited | Financial services | 2022 |
| Scullen Ltd | Administrative & support | 2024 |
| Sculpt Studio Fitness Limited | Arts & recreation | 2023 |
| Scutts Renovations Ltd | Construction | 2019 |
| Scutts Roofing Ltd | Construction | 2021 |
| SD Integrated Systems Ltd | Information & communication | 2014 |
| SD Southeast Limited | Construction | 2021 |
| Sdds Property Limited | Real estate | 2019 |
| Sdis Ltd | Information & communication | 2025 |
| SDS Retails Ltd | Wholesale & retail | 2025 |
| SE Active Sports Limited | Other services | 2022 |
| SE16 Properties Limited | Real estate | 2024 |
| Sea Thong Ltd | Hospitality | 2018 |
| Seagull Gifts UK Ltd | Other services | 2019 |
| Sean Daly Limited | Health & social care | 2023 |
| Seapearl Consultancy Limited | Wholesale & retail | 2021 |
| Seaseeker Charters Ltd | Transport & logistics | 2018 |
| Seaside Rendezvous Limited | Real estate | 2020 |
| Seatchills Limited | Construction | 2014 |
| Second Nature Vintage Limited | Wholesale & retail | 2025 |
| Second Neric Limited | Financial services | 1977 |
| Second Principle Ltd | Professional & scientific | 2022 |
| Secret Glam Ltd | Other services | 2021 |
| Secret ME Limited | Other services | 2012 |
| Sectech Limited | Information & communication | 1997 |
| Sedlescombe Golf Club Management Limited | Arts & recreation | 1997 |
| Seeds of Joy Ltd | Education | 2025 |
| Seek YE First Limited | Other services | 2013 |
| Seeway Healthcare Services Limited | Health & social care | 2019 |
| Seeway International Services Limited | Health & social care | 2017 |
| Segday Ltd | Health & social care | 2022 |
| Segunda Management Ltd | Households | 2005 |
| Seiba Tech Ltd | Manufacturing | 2026 |
| Seidelbaum Group Ltd | Financial services | 2018 |
| Seido AI Ltd | Information & communication | 2025 |
| SEL Music Education Ltd | Education | 2023 |
| Selby Block Management Company Limited | Households | 2006 |
| Selby Capital Partners Limited | Financial services | 2023 |
| Selecta(Redweb)Dna Limited | Administrative & support | 2005 |
| Selene One Ltd | Administrative & support | 2025 |
| Selhurst Construction Limited | Construction | 2015 |
| Selks Ltd | Transport & logistics | 2025 |
| Selvanathan Ltd | Real estate | 2023 |
| Selworthy Maintenance Limited | Households | 1973 |
| SEM Gemelli Limited | Construction | 2022 |
| Sema Consulting Limited | Professional & scientific | 2015 |
| Sembl Ltd | Information & communication | 2026 |
| Semorix Limited | Information & communication | 2026 |
| SEN Thai Massage Ltd | Other services | 2012 |
| Sener Property Services Limited | Real estate | 2016 |
| Sense 7 Management Company Limited | Households | 2007 |
| Sense and Sound CIC | Arts & recreation | 2026 |
| Sensi Foods Ltd | Manufacturing | 2017 |
| Sensiad Consulting Ltd | Professional & scientific | 2023 |
| Sentinel (Watford) Management Company Limited | Households | 2008 |