| Rosewood Projects Group Ltd | Construction | 2026 |
| Ross Business Solutions Limited | Professional & scientific | 2002 |
| Rural Health & Fitness Ltd | Health & social care | 2020 |
| Rural Health and Wellness Ltd | Other services | 2025 |
| Rush Green Preschool Ltd | Education | 2016 |
| Russell Utilities Ltd | Construction | 2012 |
| S a Tax Services Limited | Professional & scientific | 2021 |
| S F Assets Ltd | Real estate | 2022 |
| S&D Barbers Ltd | Other services | 2023 |
| S&G Photography Ltd | Extraterritorial | 2019 |
| S. T. Automotive Solutions Ltd | Other services | 2025 |
| S.A.L.E. Property Limited | Real estate | 2019 |
| Sajem Sourcing Ltd | Manufacturing | 2021 |
| Saker Estates Limited | Real estate | 2008 |
| Sally Lunn Management Limited | Real estate | 1986 |
| Sally's Skates Limited | Arts & recreation | 2012 |
| SAM Gilley Boxing Limited | Arts & recreation | 2025 |
| Satnam Convenience UK Limited | Wholesale & retail | 2017 |
| SAW Mill Road Management Ltd | Real estate | 2023 |
| Schwier Farms Limited | Agriculture & fishing | 1953 |
| Scribe Ltd | Construction | 1997 |
| Searlco Ltd | Professional & scientific | 2020 |
| Seashell Consulting Limited | Professional & scientific | 2024 |
| Seasoned Events Limited | Hospitality | 2000 |
| Seasoned Venues Ltd | Hospitality | 2000 |
| Seaview Avenue (Vange) Residents Association Limited | Real estate | 1991 |
| Security Image Solutions Ltd | Construction | 2003 |
| Sejuiced Limited | Manufacturing | 2004 |
| Sentinel UK Group Ltd | Information & communication | 2026 |
| Servus Enterprises Limited | Professional & scientific | 2018 |
| Setserve Ltd | Professional & scientific | 2023 |
| SF Ticket Bookers Ltd | Arts & recreation | 2021 |
| Shanbell Limited | Administrative & support | 2000 |
| Shea Lolin Limited | Arts & recreation | 2011 |
| Sheridan Enterprises Ltd | Transport & logistics | 2023 |
| Shiloh Ministries Limited | Other services | 2014 |
| Shiloh Networking Group Limited | Professional & scientific | 2014 |
| Shoreline Construction Limited | Construction | 1998 |
| Shotokan Karate Clubs Ltd | Arts & recreation | 2019 |
| Showcase AVI Ltd | Other services | 2014 |
| Showcase Group Holdings Limited | Financial services | 2024 |
| Showcase Interiors Limited | Wholesale & retail | 2007 |
| Showcase PSR Limited | Wholesale & retail | 2007 |
| Showcase PSR Portsdown Limited | Wholesale & retail | 1983 |
| Shreeve and SON Limited | Construction | 2012 |
| Shreeve Building Ltd | Construction | 2026 |
| Sigma Consulting Limited | Information & communication | 1996 |
| Simple Management Systems Limited | Professional & scientific | 2023 |
| Simply Ironing Ltd | Other services | 2022 |
| Simpsons Bespoke Interiors Limited | Construction | 2010 |
| Site Snacks Ltd | Wholesale & retail | 2026 |
| Sjkr Limited | Real estate | 2025 |
| SJM Health Limited | Financial services | 2009 |
| Skautoandgm Ltd | Wholesale & retail | 2021 |
| Skin by Carly Kent Ltd | Other services | 2022 |
| Skipduct Ltd | Construction | 2019 |
| Sky Blue (Colchester) Ltd | Manufacturing | 2024 |
| Skytrack Worldwide Limited | Transport & logistics | 2004 |
| Skywalker Roofing Limited | Construction | 2025 |
| Slrkproperties Limited | Hospitality | 2025 |
| SLS Concept Limited | Real estate | 2018 |
| Smart Choice Alloys Ltd | Wholesale & retail | 2025 |
| Smart Choice Flooring Ltd | Construction | 2025 |
| Smartway Scaffolding Ltd | Construction | 2023 |
| SMR Advanced Healthcare Solutions Limited | Health & social care | 2012 |
| Snapit Screw International Limited | Manufacturing | 2013 |
| SNC Plant Solutions Ltd | Manufacturing | 2016 |
| Solomon Electrical Services Limited | Administrative & support | 2003 |
| Somfero Group Limited | Professional & scientific | 2013 |
| SOS Cleaning Agency Ltd | Administrative & support | 2025 |
| South Essex Environmental Solutions Limited | Construction | 2017 |
| Southeast Flooring Services Ltd | Construction | 2024 |
| Sovereign Storage Ltd | Transport & logistics | 2023 |
| Speech Therapy Services London Ltd | Education | 2015 |
| Spencer Smith Partners Ltd | Real estate | 2025 |
| Speyhawk Cleaning Services Ltd | Administrative & support | 2022 |
| SPK Pallets Limited | Wholesale & retail | 2026 |
| Splendid Cars Ltd | Wholesale & retail | 2022 |
| Splendid Hand Car Wash Ltd | Other services | 2011 |
| Sprays and Rays Limited | Other services | 2005 |
| Spring Court (Hermon Hill) Limited | Professional & scientific | 2000 |
| SR Employment and Training CIC | Administrative & support | 2015 |
| ST George Homes Ltd | Extraterritorial | 2023 |
| ST George Residential Limited | Real estate | 2015 |
| ST James (1) Management Company Limited | Households | 2004 |
| ST Jude and ST James Limited | Other services | 2025 |
| ST Mary Kiro Mina Courier Limited | Transport & logistics | 2002 |
| ST. James Court (Highwoods) Management Limited | Households | 1988 |
| Stac Search Limited | Administrative & support | 2024 |
| Stag Building Services Limited | Construction | 2002 |
| Stallion Distribution Ltd | Transport & logistics | 2023 |
| Stambridge Developments Ltd | Financial services | 2014 |
| Stambridge Management Limited | Households | 2023 |
| Stamps and Stamps Limited | Professional & scientific | 2026 |
| Stand UP Pubs Ltd | Hospitality | 2022 |
| Stanford Rivers Hall Farm Management Company Limited | Households | 1999 |
| STANLEY111 Limited | Manufacturing | 2014 |
| Star 32 Property Management Ltd | Real estate | 2022 |
| Starry Eyed Events Ltd | Professional & scientific | 2018 |
| Starz Presents Limited | Information & communication | 2024 |