| Soulbird Ltd | Health & social care | 2025 |
| Sound Law Ltd | Other services | 2024 |
| Sound Minds & Solid Hearts Limited | Education | 2018 |
| Sound Minds and Strong Hearts Community Interest Company | Education | 2017 |
| Sourceking Properties Limited | Real estate | 2024 |
| South East Building Services (UK) Ltd | Construction | 2010 |
| South East Climbing - Chatham Limited | Arts & recreation | 2023 |
| South East Corporation Ltd | Construction | 2020 |
| South East Double Glazing Ltd | Construction | 2017 |
| South East Drainage Ltd | Water & waste | 2019 |
| South East Electrical Limited | Construction | 2008 |
| South East Portable Appliance Testing Ltd | Professional & scientific | 2023 |
| South East Property Solutions Ltd | Real estate | 2025 |
| South Eastern Access Ltd | Construction | 2018 |
| South Essex Sand & Gravel Limited | Administrative & support | 2009 |
| South London Plumbing Services Ltd | Construction | 2020 |
| South Maritime Residents Limited | Other services | 1996 |
| South Patagonia Ltd | Wholesale & retail | 2025 |
| South Place Construction Ltd | Construction | 2023 |
| Southeast Contracting Limited | Construction | 2018 |
| Southeast Repointing Specialists Ltd | Construction | 2024 |
| Southeast Waste Water Removal Limited | Water & waste | 2025 |
| Southern Carpentry & Sons Ltd | Construction | 2025 |
| Southern Properties & Developments Ltd | Real estate | 2019 |
| Southfleet Investments Limited | Construction | 1962 |
| Southfleet Solutions Ltd | Construction | 2021 |
| Southill MOT Centre Ltd | Wholesale & retail | 2025 |
| SP Mayer Limited | Real estate | 2025 |
| SP Silicone Sealants Limited | Construction | 2025 |
| Space Finish Limited | Construction | 2026 |
| Space Reset Ltd | Administrative & support | 2026 |
| Spaford Electro and Mechanic Services Limited | Construction | 1978 |
| Sparkle Oak Cleaning Solutions Limited | Administrative & support | 2025 |
| Sparkling Gems Ltd | Wholesale & retail | 2024 |
| Sparkling Ideas Limited | Information & communication | 2009 |
| Sparkling Staffing Ltd | Administrative & support | 2018 |
| Sparks Psychology Ltd | Education | 2026 |
| Sparks That FLY Ltd | Construction | 2024 |
| Spear Point Recruitment Limited | Construction | 2015 |
| Spec Motion Ltd | Administrative & support | 2019 |
| Speedadmin Ltd | Information & communication | 2023 |
| Speedex Carriers Limited | Transport & logistics | 2020 |
| Speedy Sheet Metal Limited | Manufacturing | 1973 |
| Spence Land & Development Limited | Real estate | 2009 |
| Spice Children Holdings Ltd | Real estate | 2022 |
| Spice Village Lordswood Ltd | Hospitality | 2024 |
| Spikeline Ltd | Construction | 2019 |
| Spinosaurus Media Ltd | Professional & scientific | 2020 |
| SPJ Plumbing Services Ltd | Construction | 2022 |
| Spoon Chatham Ltd | Hospitality | 2022 |
| Spooner Plumbing & Heating Limited | Construction | 2002 |
| Sportline Management Ltd | Arts & recreation | 2014 |
| Sports 4 Change C.I.C. | Education | 2022 |
| Sports Power Limited | Wholesale & retail | 1995 |
| SPORTS4ALL Curriculum Limited | Education | 2026 |
| Spotlites Theatre Company Limited | Arts & recreation | 2004 |
| Spotted Tiger Coaching and Consulting Limited | Professional & scientific | 2023 |
| SPR Trading Limited | Hospitality | 2025 |
| Spraytone Finishing Limited | Construction | 2008 |
| Spreading Sparks Limited | Construction | 2026 |
| Spree NON Destructive Testing Co Ltd | Professional & scientific | 2025 |
| Springate Close Management Company Ltd | Households | 2022 |
| Sprinkler ED Limited | Administrative & support | 2005 |
| SPS Property Management Southeast Limited | Real estate | 2019 |
| Square Bubble Factory Limited | Professional & scientific | 2013 |
| Squirrell's Riding School Ltd | Arts & recreation | 2021 |
| Squirrells Livery Limited | Arts & recreation | 2012 |
| SR & Co Ventures Ltd | Real estate | 2025 |
| SR Dreams Ltd | Real estate | 2025 |
| SR Medicare Limited | Health & social care | 2012 |
| SRF Carpentry Ltd | Construction | 2021 |
| SRG Sandhu Limited | Wholesale & retail | 2022 |
| SRH (Electrical Engineering) Limited | Administrative & support | 2009 |
| SRH Psychology Ltd | Education | 2024 |
| Srirangam Ltd | Real estate | 2020 |
| Srish.S.Indian.Takeaway Ltd | Hospitality | 2023 |
| SRS Energy Solutions Limited | Administrative & support | 2019 |
| SS Medical Solutions Ltd | Health & social care | 2023 |
| Ssjes Construction Limited | Construction | 2024 |
| SSK Hair and Beauty Limited | Other services | 2025 |
| SSM Enterprises Ltd | Wholesale & retail | 2025 |
| ST Augustine's Past Students Union - UK Ltd | Education | 2024 |
| ST Bambinos Nursery and Preschool Ltd | Education | 2018 |
| ST Charles Medics Ltd | Health & social care | 2024 |
| ST George's Place Limited | Financial services | 2021 |
| ST George's Place Property Limited | Real estate | 2021 |
| ST George's School of Business & Finance Ltd | Education | 2018 |
| ST Leonards Place Ltd. | Health & social care | 1995 |
| ST Mary's Island Planners Ltd | Professional & scientific | 2026 |
| ST Mary's Island Residents Association Limited | Other services | 1996 |
| ST. Anselm's Nursing Home Limited | Health & social care | 1991 |
| ST. James's Counsel Limited | Professional & scientific | 2024 |
| ST. Mary's Healthcare and Recruitment Ltd | Administrative & support | 2022 |
| ST. Omer Limited | Information & communication | 2012 |
| Stable Software Ltd | Wholesale & retail | 2025 |
| Stados Ltd | Professional & scientific | 2021 |
| Stagan Limited | Real estate | 1998 |
| Stage Mobile Limited | Administrative & support | 2017 |
| Stamford Brickwork Limited | Construction | 2021 |
| Stamford Construction Limited | Construction | 2012 |