| SIR Lami Limited | Health & social care | 2020 |
| Sisi Boutique Ltd | Wholesale & retail | 2025 |
| Sister's Trading Ltd | Wholesale & retail | 2024 |
| Sister’S Property Investment Limited | Real estate | 2026 |
| Skelmersdale Properties Ltd | Financial services | 2017 |
| Skill at Arms Limited | Arts & recreation | 2020 |
| Skirts 2 Skills Ltd | Wholesale & retail | 2026 |
| Sky Haven Digital Ltd | Information & communication | 2026 |
| Skyline Court RTM Company Limited | Households | 2008 |
| Slay Sustainable Fashion Limited | Wholesale & retail | 2025 |
| SLP Builders Ltd | Construction | 2022 |
| Smart Bookkeeping Services (Essex) Limited | Administrative & support | 2018 |
| Smartline Management Ltd | Professional & scientific | 2026 |
| SMC Electrical Essex Limited | Construction | 2018 |
| Smith Family Funeral Directors Ltd | Other services | 2023 |
| Smith Farms (Clacton) Limited | Agriculture & fishing | 1947 |
| Smrd & Co Ltd | Real estate | 2025 |
| Snappysnaps Clacton Ltd | Wholesale & retail | 2022 |
| Snootiful Hound Ltd | Wholesale & retail | 2023 |
| Sola-Soba Enterprise Ltd | Administrative & support | 2022 |
| Solo Cheese Ltd | Hospitality | 2017 |
| Solutions Hair & Beauty Ltd | Other services | 2018 |
| Somerset Financial Services Limited | Financial services | 2017 |
| Somewhere to Live Ltd | Real estate | 2002 |
| Sourceted Limited | Wholesale & retail | 2021 |
| Southcliffe Court Management Company Ltd. | Households | 1989 |
| Southern Property (UK) Limited | Real estate | 2006 |
| Spa Productions Limited | Arts & recreation | 2025 |
| Spades Properties Limited | Real estate | 2012 |
| Specialised Engineering and Fabrication Ltd | Professional & scientific | 2020 |
| Spectrum Investigations Ltd | Administrative & support | 2021 |
| Spectrum Media & Management Ltd. | Information & communication | 2019 |
| Spirit & Spice Ltd | Wholesale & retail | 2022 |
| Spirit Brands Ltd | Wholesale & retail | 2013 |
| SPK Fire Ltd | Construction | 2026 |
| Splashnet Limited | Information & communication | 2022 |
| Springfield Court RTM Company Limited | Households | 2005 |
| Spuklpmc Ltd | Real estate | 2022 |
| SRW Electrical Limited | Construction | 2016 |
| SRW GRP Ltd | Extraterritorial | 2021 |
| Ssgleds Limited | Energy | 2026 |
| ST Andrews House RTM Company Limited | Households | 2023 |
| ST Helena Financial Limited | Financial services | 2018 |
| ST Margarets Gardens (Chelmsford) Management Company Limited | Households | 1993 |
| ST Osyth Boatyard Ltd | Manufacturing | 2014 |
| ST Osyth Butchers Ltd | Wholesale & retail | 2013 |
| ST Osyth Preschool CIC | Education | 2010 |
| St-Johns Oak Clacton Ltd | Real estate | 2023 |
| ST. Barnabas Court Limited | Households | 2007 |
| ST. Paul's Management Company Clacton on Sea Limited | Extraterritorial | 2005 |
| Stagefrights Murder Mysteries LLP | | 2023 |
| Stainton Road 1960 Limited | Extraterritorial | 2014 |
| Standby Driving Instructor Limited | Education | 2025 |
| Stannardconsultants Limited | Professional & scientific | 2026 |
| Stannett Electrical Ltd | Construction | 2025 |
| Star Nails & Beauty (Clacton) Limited | Other services | 2014 |
| Star Nails Clacton Ltd | Other services | 2026 |
| Starkey Property Developments Limited | Real estate | 2025 |
| Startup Networks Limited | Administrative & support | 2024 |
| Station Road Convenience Ltd | Wholesale & retail | 2024 |
| Status QUO Limited | Professional & scientific | 1998 |
| Stavert Mode Ltd | Wholesale & retail | 2026 |
| Steam Powered Education Ltd | Education | 2019 |
| Stebbing and Sons Limited | Agriculture & fishing | 1959 |
| Steels Plumbing & Heating Ltd | Construction | 2019 |
| Steffy Autos Ltd | Wholesale & retail | 2024 |
| Stephen Rampton Limited | Construction | 2015 |
| Stevieb Properties Limited | Real estate | 2023 |
| Sting Ltd | Real estate | 2025 |
| Stone Hall Homes Management Company Limited | Households | 2018 |
| Stonehouse Tiling Limited | Construction | 2026 |
| Storage Solutions (E & S) Limited | Administrative & support | 2011 |
| Stronger Maths Limited | Education | 2022 |
| Sttav Group Limited | Construction | 2017 |
| Stuart Poulton Limited | Other services | 2004 |
| Stylegain Ltd | Hospitality | 2008 |
| Subtle Studio Aesthetics Ltd | Other services | 2023 |
| SUE MAY Consulting Ltd | Professional & scientific | 2011 |
| Summit Group Solutions Ltd | Professional & scientific | 2026 |
| Sun Spa 11 Ltd | Other services | 2024 |
| Sunkissed Barbers & Beauty Salon Ltd | Other services | 2025 |
| Sunnyside Homes Ltd | Construction | 1998 |
| Sunnyside Mews Ltd | Real estate | 2014 |
| Super Leisure Limited | Wholesale & retail | 2011 |
| Supreme Auto Services Ltd | Wholesale & retail | 2021 |
| Supreme Installs Ltd | Construction | 2024 |
| Supreme Moisture Ltd | Wholesale & retail | 2026 |
| Surffix Ltd. | Administrative & support | 2026 |
| Surprised Hotdog Limited | Wholesale & retail | 2021 |
| SW Highways Ltd | Transport & logistics | 2021 |
| SW Small Ltd | Construction | 2018 |
| Swan Taxis Clacton Ltd | Transport & logistics | 2006 |
| Swbc Essex Limited | Transport & logistics | 2026 |
| Swinbourne GAS Services Ltd | Construction | 2017 |
| Sycamore Place Limited | Households | 2019 |
| Systra AI Ltd | Information & communication | 2024 |
| T J Construction Ltd | Manufacturing | 2019 |
| T M GAS Limited | Construction | 2019 |
| T&D Contractors (Essex) Ltd | Construction | 2023 |
| T&K Building and Construction Limited | Construction | 2014 |