| Rutlen IT Ltd | Information & communication | 2024 |
| RV VET Limited | Professional & scientific | 2017 |
| Ryelake Limited | Professional & scientific | 2018 |
| Ryga Properties Limited | Construction | 1970 |
| S & E Invest Ltd | Real estate | 2014 |
| S & L Contracting Limited | Construction | 1989 |
| S & V Traders Limited | Wholesale & retail | 2016 |
| S and V Projects Ltd | Real estate | 2019 |
| S Deacon QA Consultants Ltd | Health & social care | 2022 |
| S Ford Electrical Ltd | Construction | 2022 |
| S J Durman Flooring Ltd | Construction | 2009 |
| S&Fr Investments Limited | Real estate | 2022 |
| S&I Projects Ltd | Construction | 2019 |
| S&K Trading Ltd | Wholesale & retail | 2021 |
| S&W Support Ltd | Professional & scientific | 2023 |
| S. B. Watson & Sons Glazing Contractors Ltd | Construction | 2012 |
| S. E. Appliance Services Ltd | Manufacturing | 2017 |
| S.A.S. Small Animal Surgery Limited | Professional & scientific | 2023 |
| S.B. & C.Developments Limited | Real estate | 1962 |
| S.G.Generals Building Ltd | Construction | 2016 |
| S.Southey Consultancy Ltd | Public administration | 2014 |
| S.T.W. Finance and Leasing Company Limited | Transport & logistics | 2000 |
| Safe Refuge Ltd | Hospitality | 2020 |
| Sagrada Familia Limited | Information & communication | 2022 |
| Saitch & Co Ltd | Construction | 2026 |
| Saksinto Ltd | Arts & recreation | 2018 |
| Salkind Imports Ltd. | Real estate | 1988 |
| Sally Torr Trends Limited | Wholesale & retail | 2025 |
| Salpro Estates Ltd | Real estate | 2020 |
| Samdav Ltd | Health & social care | 2021 |
| Sapore the Italian House Ltd | Hospitality | 2025 |
| Sarah Khariuk Limited | Health & social care | 2012 |
| Savortime Ltd | Wholesale & retail | 2024 |
| Sawaddee Thai Food Limited | Hospitality | 2017 |
| Saxby Home Solutions Ltd | Construction | 2025 |
| Saxons Auto Services Limited | Wholesale & retail | 2016 |
| Saxons MOT Services Limited | Wholesale & retail | 2017 |
| SB & FF Properties Limited | Real estate | 2025 |
| SB Landscapes and Groundworks Ltd | Construction | 2024 |
| SBJ Services (Essex) Limited | Administrative & support | 2014 |
| SBL Fire Solutions Ltd | Construction | 2011 |
| SC Health Care Solutions Limited | Administrative & support | 2024 |
| Scaffold Lift Specialists Limited | Construction | 2021 |
| Scallywags Day Nursery Limited | Health & social care | 2005 |
| Scallywags Nursery Chelmsford Limited | Health & social care | 2009 |
| Scenic Groundcare Ltd | Administrative & support | 2017 |
| School of Aesthetic Medicine Limited | Education | 2021 |
| School of Hair & Beauty by Helen Jane Limited | Education | 2026 |
| Sclect Properties Limited | Real estate | 2018 |
| Scott Mcarthur Engineering Contractors Limited | | 1963 |
| Scott's Carpets Vinyl Wood Limited | Construction | 2022 |
| Scouts of Leigh Limited | Hospitality | 2018 |
| Screedflo Ltd | Construction | 2006 |
| Screedflo.Co.Uk Ltd | Professional & scientific | 2006 |
| Scriptex Property Services Ltd | Real estate | 2026 |
| Scriptex Services Ltd | Construction | 2021 |
| SD Mclaughlin and Associates Ltd | Health & social care | 2026 |
| SDW Engineering Ltd | Professional & scientific | 2025 |
| Sealant Application Specialists Limited | Construction | 2001 |
| Sealbase Limited | Construction | 2014 |
| Sealed Units Direct Limited | Manufacturing | 2025 |
| Seales Specialist Services Division Ltd | Administrative & support | 2017 |
| Second Hand Toys Bexley Limited | Wholesale & retail | 2024 |
| Secondary Glazing Online Limited | Manufacturing | 2026 |
| Security Product Installations Ltd | Other services | 2019 |
| Security Recruitment Specialists Worldwide Limited | Administrative & support | 2013 |
| SEG Orthodontics Ltd | Health & social care | 2024 |
| Selim Cleaning Ltd | Administrative & support | 2023 |
| Senovo Resourcing Ltd | Administrative & support | 2025 |
| Sentinel Contracting Group Limited | Financial services | 2020 |
| Sentinel Contracting PLC | Construction | 2014 |
| Sequel Construction Ltd | Construction | 2020 |
| Serena Days Limited | Wholesale & retail | 2020 |
| Serendipity Cafe Southend C.I.C. | Hospitality | 2022 |
| SET Mechanical & Electrical Services Ltd | Construction | 2021 |
| Sevyn HQ Ltd | Wholesale & retail | 2025 |
| SFB Solutions Limited | Administrative & support | 2017 |
| SGB (SW) Properties Limited | Real estate | 2018 |
| SGS Electrical Ltd | Construction | 2018 |
| Sharp Skills Limited | Education | 2019 |
| Shaves Building & Electrical Services Ltd | Construction | 2021 |
| Shel's N Tel's Ltd | Other services | 2026 |
| Sheridan House Limited | Real estate | 1997 |
| Sheriffs Fencing Ltd | Wholesale & retail | 2024 |
| Sherwood Taylor & Whyte Limited | Professional & scientific | 2002 |
| Shiftall Limited | Real estate | 1973 |
| Ship and Trade Corporate Services Ltd | Administrative & support | 2012 |
| Ship's Dog Publishing Ltd | Information & communication | 2020 |
| Shirestride Limited | Real estate | 1999 |
| SHL Utilities Ltd | Construction | 2022 |
| Shoad Consultancy Ltd | Professional & scientific | 2019 |
| Shoebury Hotel Limited | Real estate | 2011 |
| SHOP321 Ltd | Wholesale & retail | 2015 |
| SHOP4321 Ltd | Wholesale & retail | 2020 |
| Shoulder of Mutton Ltd | Hospitality | 2025 |
| Sibbons Plumbing Ltd | Construction | 2026 |
| Silk Road Daughters Limited | Wholesale & retail | 2023 |
| Silk Road Junior Limited | Wholesale & retail | 2023 |
| Silk Road MEN Limited | Wholesale & retail | 2023 |
| Silk Road Sons Limited | Wholesale & retail | 2023 |