| Samj Building Services Limited | Construction | 2013 |
| Sanctuary Cleaning Ltd | Administrative & support | 2025 |
| Sandbeds Pharmacy Limited | Wholesale & retail | 1993 |
| Sani Laco. Limited | Construction | 2022 |
| Sanni Property Worldwide Ltd | Real estate | 2025 |
| Sans Club Ltd | Wholesale & retail | 2024 |
| Sapphire Holdings South East Limited | Extraterritorial | 2023 |
| Sapphire Steel Fabrications Limited | Construction | 2023 |
| Sarg Limited | Professional & scientific | 2024 |
| Sauk Distributions Ltd | Wholesale & retail | 2022 |
| Saxon Education Ltd | Professional & scientific | 2025 |
| SB Capital Limited | Construction | 2015 |
| SC Fire & Electrical Services Ltd | Construction | 2019 |
| Scaleuptech Solutions Ltd | Information & communication | 2024 |
| Scalliwags Pre-School Nursery Limited | Education | 2026 |
| Scapri Ltd | Health & social care | 2024 |
| Schoolfield Properties Limited | Construction | 2023 |
| Scope Pharma Limited | Wholesale & retail | 2025 |
| Seade Money Limited | Other services | 2020 |
| Seal Right Sealants Ltd | Manufacturing | 2024 |
| Seales Gordon Aggregates Limited | Other services | 2025 |
| SEB Engineering Ltd | Professional & scientific | 2023 |
| Seba Healthcare Services Ltd | Professional & scientific | 2021 |
| Second Builder Ltd | Construction | 2023 |
| Seig (2007) Number 2 Limited | Financial services | 2007 |
| Sekhon Properties Development Ltd | Real estate | 2018 |
| Sekhon Transport Ltd | Transport & logistics | 2016 |
| Sellon Tower Ltd | Households | 2022 |
| Selluc Ltd | Transport & logistics | 2023 |
| Senanayake IT Consultants Limited | Information & communication | 2016 |
| Senza Consultancy Ltd | Information & communication | 2025 |
| Ser&Mad Ltd | Transport & logistics | 2025 |
| Serendipity Solutions Ltd | Administrative & support | 2019 |
| Serg.R Construction Ltd | Construction | 2026 |
| Serlat Brickwork Ltd | Construction | 2023 |
| Sfiar Ltd | Other services | 2014 |
| SG Glazing Limited | Construction | 2020 |
| SHA Supply & Co Limited | Administrative & support | 2026 |
| Shaema Properties Ltd | Real estate | 2017 |
| Shammah-Vital Services Ltd | Real estate | 2025 |
| Shan Science Ltd | Education | 2025 |
| Shark Motor Group Ltd | Professional & scientific | 2026 |
| Shaw Primary Academy | Education | 2012 |
| Shepherds Walk Homes Ltd | Construction | 2018 |
| Sheraz Limited | Transport & logistics | 2015 |
| Shile Property Limited | Real estate | 2023 |
| Shiloh Property Solutions Ltd | Households | 2024 |
| Shindygb Limited | Health & social care | 2026 |
| Ship Lane Autos Ltd | Wholesale & retail | 2023 |
| Shiphrah Puah Ltd | Professional & scientific | 2018 |
| SHO Services Limited | Health & social care | 2022 |
| Shopfront Solutions UK Ltd | Manufacturing | 2017 |
| Shopperxx Mart Limited | Wholesale & retail | 2025 |
| Shoppingbucket Limited | Wholesale & retail | 2025 |
| Shreeji Venture Ltd | Wholesale & retail | 2024 |
| SHY Investments (International) Limited | Wholesale & retail | 2008 |
| Signature Craftz Ltd | Other services | 2019 |
| Sigr AI Limited | Other services | 2025 |
| Silgo Lubricants Limited | Wholesale & retail | 1973 |
| Silvio DE Marin Ltd | Construction | 2021 |
| SIM Gear Giveaways Ltd | Other services | 2023 |
| Sima Sells Ltd | Wholesale & retail | 2025 |
| Similee Limited | Health & social care | 2018 |
| Simply EV Limited | Wholesale & retail | 2024 |
| Siroc Properties Ltd | Real estate | 2022 |
| Siroc Solutions Limited | Real estate | 2022 |
| Siziba Inc Limited | Health & social care | 2018 |
| SJD Commerce Ltd | Wholesale & retail | 2026 |
| SJM and Sons Interiors Ltd | Construction | 2024 |
| Skaira Consulting Limited | Information & communication | 2022 |
| Skill Axis Ltd | Administrative & support | 2024 |
| SKS Domos Ltd | Real estate | 2025 |
| Sky Elite Estate and Properties Management Ltd | Real estate | 2021 |
| Sky Moon Cars Ltd | Wholesale & retail | 2018 |
| Skyline Therapies Consultancy Ltd | Public administration | 2024 |
| Skyworth Investment Limited | Mining & quarrying | 2018 |
| Slemendon Solutions Ltd | Information & communication | 2018 |
| Smarr PCO Ltd | Administrative & support | 2024 |
| Smart Elec-Trix Ltd | Construction | 2022 |
| Smellie Designs Limited | Professional & scientific | 1998 |
| Smithsglobalenergy Ltd | Construction | 2025 |
| Smqb Rentals Limited | Households | 2017 |
| SNI Properties Limited | Real estate | 2019 |
| SOA Holdings Limited | Real estate | 2023 |
| Sofy & Lara Ltd | Transport & logistics | 2020 |
| Solinx Global Limited | Information & communication | 2009 |
| Solomon UK Services Limited | Construction | 2018 |
| Solvik Haulage Ltd | Transport & logistics | 2022 |
| Soni Transport Limited | Transport & logistics | 2023 |
| Sonora Ltd | Other services | 2014 |
| Sonrak Limited | Wholesale & retail | 1994 |
| Sook Ventures Ltd | Information & communication | 2018 |
| Sophia Construct Ltd | Other services | 2016 |
| Sophos Operational Solutions Ltd | Water & waste | 2015 |
| Sorin Handyman Limited | Other services | 2010 |
| Soritrans Ltd | Transport & logistics | 2018 |
| SOS Cleaning& Disinfecting Ltd | Administrative & support | 2020 |
| South Close Residents Company Limited | Extraterritorial | 2014 |
| Southeast Painting Contractors Ltd | Construction | 2025 |
| Southminster Limited | Construction | 1995 |