| Shotley Marina Limited | Arts & recreation | 1993 |
| Shotter Investments Limited | Real estate | 2017 |
| Shourai Marine Claims Ltd | Transport & logistics | 2022 |
| Shourai Properties Ltd | Real estate | 2023 |
| Shoutly Ltd. | Information & communication | 2025 |
| Shrublands Court Residents Association (Tunbridge Wells) Limited | Households | 1974 |
| Shruti Soni Ltd | Professional & scientific | 2014 |
| Shutter Base Limited | Construction | 2023 |
| Shutter Studio Limited | Construction | 2021 |
| Sienna Building Limited | Real estate | 2019 |
| Sight SWS Ltd | Manufacturing | 2024 |
| Signature Cashmere Limited | Wholesale & retail | 2022 |
| Signature Homecare Limited | Extraterritorial | 2021 |
| Signature Sports Products Ltd | Wholesale & retail | 2019 |
| Silchester Asset Management Limited | Real estate | 2013 |
| Silico Research Limited | Professional & scientific | 1996 |
| Silk Mills Close Management Company Limited | Real estate | 1997 |
| Silk Screening Print Services Limited | Manufacturing | 2015 |
| Silkwood Capital Ltd | Financial services | 2025 |
| Silver Teal Ltd | Professional & scientific | 2023 |
| Silverleigh Spa Limited | Arts & recreation | 2009 |
| Silverley Limited | Financial services | 2021 |
| Silverlining Printing Ltd | Manufacturing | 2023 |
| Silverray & Sons Limited | Real estate | 2026 |
| Silvertongue Marketing Ltd | Professional & scientific | 2026 |
| Simba Property Management Limited | Real estate | 2012 |
| Simber Consulting Limited | Professional & scientific | 2015 |
| Similarish Ltd | Wholesale & retail | 2022 |
| Simko Limited | Manufacturing | 2024 |
| Simmim Limited | Hospitality | 2025 |
| Simon Sivyer Associates Ltd | Professional & scientific | 2025 |
| Simon Townshend Limited | Professional & scientific | 2009 |
| Simon's Tidy Gardens Limited | Other services | 2003 |
| Simple Clean Limited | Construction | 2016 |
| Simple Drainage Limited | Water & waste | 2025 |
| Simple Machine Limited | Information & communication | 2014 |
| Simplicius Finance Transformation Ltd | Other services | 2016 |
| Simply Natures Way Ltd | Manufacturing | 2017 |
| Simply Private Limited | Manufacturing | 2013 |
| Simply Staffed Ltd | Administrative & support | 2023 |
| Simpson Froud LLP | | 2013 |
| Simwel Properties Ltd. | Administrative & support | 2021 |
| Sinclair Treasury Consultants Limited | Professional & scientific | 2022 |
| Sine Health Limited | Information & communication | 2025 |
| Sinoble Limited | Professional & scientific | 2024 |
| Siraj Journeys Limited | Administrative & support | 2025 |
| Sirena Vista Global Trading Limited | Wholesale & retail | 2026 |
| Sirium Limited | Real estate | 2017 |
| Sirium Solutions Limited | Information & communication | 2018 |
| Site Sound Limited | Construction | 2008 |
| Site Studios Ltd | Construction | 2025 |
| Sitex Industrial Limited | Wholesale & retail | 2017 |
| Sixxx Records Limited | Administrative & support | 2003 |
| SJ Shaw Consulting Ltd | Professional & scientific | 2008 |
| SJB Building Services Limited | Construction | 2018 |
| SJF Associates UK Ltd | Real estate | 2024 |
| SJP Body Repairs Ltd | Wholesale & retail | 2022 |
| SJP Van Repairs Ltd | Wholesale & retail | 2024 |
| SK Gym Group Limited | Arts & recreation | 2017 |
| SK Hotel Associates Ltd | Professional & scientific | 2025 |
| SKA Brockley Limited | Wholesale & retail | 2017 |
| Skillclear Limited | Information & communication | 2002 |
| Skillsprint CIC | Education | 2025 |
| Skin Food. Ltd | Wholesale & retail | 2025 |
| Skin in the Game London Ltd | Wholesale & retail | 2024 |
| Skipjak Technologies Ltd | Information & communication | 2024 |
| Skull Mountain Ltd | Professional & scientific | 2016 |
| Sky Osei-Mensah Associates Ltd | Professional & scientific | 2023 |
| Skyfield Construction Ltd | Construction | 2022 |
| Skyfield Developments Ltd | Construction | 2024 |
| Skyla MAE Lifestyle Ltd | Wholesale & retail | 2023 |
| Skyline Claims Solutions Ltd | Professional & scientific | 2026 |
| Skyline Engineering (South East) Limited | Construction | 2012 |
| Skytree Media Ltd | Information & communication | 2023 |
| Slate & Stone Developments Ltd | Construction | 2026 |
| Slater Watson Ltd | Information & communication | 2020 |
| Sleep & Business School Limited | Administrative & support | 2026 |
| Slenderline Glass Ltd | Construction | 2011 |
| SLH Bookkeeping & Accounts Ltd | Professional & scientific | 2023 |
| Slipper Media Ltd | Information & communication | 2017 |
| SLJ Fitness Limited | Arts & recreation | 2017 |
| Sloane Blaire Automotive Group Ltd | Wholesale & retail | 2026 |
| Slow Cheetah Developments Ltd | Information & communication | 2026 |
| Smart Fire Health and Safety Ltd | Construction | 2002 |
| Smart Office Solutions Ltd | Information & communication | 2019 |
| Smart Real Properties Ltd | Real estate | 2016 |
| Smartample Solutions Limited | Information & communication | 2005 |
| Smartatech Limited | Information & communication | 2009 |
| Smartclaim Technology Ltd | Information & communication | 2024 |
| Smartfix I.T. Limited | Information & communication | 2003 |
| Smartlayer.Ai Limited | Information & communication | 2022 |
| Smartwave Cleaning Services Ltd | Administrative & support | 2021 |
| Smartzell International Limited | Wholesale & retail | 2016 |
| Smashing Print Ltd | Information & communication | 2014 |
| Smidt Scaffolding Ltd | Construction | 2025 |
| Smith Research and Holdings Limited | Professional & scientific | 2025 |
| Smks Studios Ltd | Information & communication | 2023 |
| Smokers Retreat Ltd | Wholesale & retail | 2023 |
| Smpl Limited | Wholesale & retail | 2021 |
| SMPLJ2 Property Ltd | Real estate | 2024 |