| Saint John Patrick Communications Limited | Information & communication | 2026 |
| Samco & Shrim Farmers Limited | Wholesale & retail | 1968 |
| Sandra Jenner Limited | Professional & scientific | 2010 |
| Sarah NYE Architecture Ltd | Professional & scientific | 2016 |
| SC Connor Limited | Administrative & support | 2008 |
| Scoria Fireplaces Limited | Wholesale & retail | 2007 |
| Scott Wilson Consulting Ltd | Professional & scientific | 2026 |
| SCR Contracts Limited | Extraterritorial | 2015 |
| Sea MAR Management Accounting Ltd | Information & communication | 2010 |
| Sears Investment Group Limited | Financial services | 2025 |
| Secio Systems Limited | Professional & scientific | 2023 |
| Seko UK Limited | Wholesale & retail | 1998 |
| Sendhurst Landscapes Limited | Administrative & support | 2019 |
| Senkenken Limited | Professional & scientific | 1999 |
| Serenity Gems Limited | Manufacturing | 2025 |
| Sglimited Limited | Construction | 2024 |
| Shaws Contractors Limited | Construction | 2011 |
| Shirehall Apartments Manco Limited | Households | 2024 |
| SI Medical Limited | Health & social care | 2002 |
| Silver Oak Ltd | Construction | 2021 |
| Sims Engineering Limited | Manufacturing | 1999 |
| Sirius Advisory Services Limited | Professional & scientific | 2016 |
| Sixlands Ltd | Transport & logistics | 2016 |
| SJ Crystals Ltd | Wholesale & retail | 2025 |
| SKV (Stortford) Properties Ltd | Real estate | 2023 |
| Slideway Associates Limited | Information & communication | 1997 |
| SM Productions Ltd | Information & communication | 2015 |
| Smart Marble Group Ltd | Manufacturing | 2024 |
| SMF Developments Limited | Construction | 2019 |
| Smile Europe Group Ltd | Other services | 2026 |
| SML Consulting Ltd | Professional & scientific | 2017 |
| Solace Healing Ltd | Other services | 2025 |
| Soul Studios Sessions Ltd | Education | 2019 |
| South Sea 2010 Limited | Real estate | 2010 |
| Southmill Court (Bishop's Stortford) Management Limited | Households | 2002 |
| Southsea Road Residents Company Limited | Professional & scientific | 2013 |
| Sovereign Development Systems Limited | Information & communication | 1994 |
| Spiralhold Limited | Financial services | 2023 |
| Spot Reels Ltd | Information & communication | 2008 |
| ST1LLL Limited | Information & communication | 2025 |
| Stakebase Limited | Professional & scientific | 1985 |
| Stanley TEE LLP | | 2007 |
| Stanley TEE Trust Corporation Limited | Administrative & support | 2025 |
| Stansted Airport Taxis Limited | Extraterritorial | 2024 |
| Stansted Lodge Limited | Hospitality | 2005 |
| Star Agro-Chem Limited | Wholesale & retail | 1984 |
| Station Coach Works Holdings Limited | Real estate | 2000 |
| Steed and Lead Ltd | Agriculture & fishing | 2020 |
| Stephanie DE Howes Limited | Information & communication | 2013 |
| Stephen Tapper Planning Limited | Professional & scientific | 2014 |
| Stericlick UK Limited | Administrative & support | 2016 |
| Steve Bates Photography Ltd | Professional & scientific | 2012 |
| Stingray J Limited | Information & communication | 2000 |
| Stort Builders Limited | Construction | 1991 |
| Stort Chemicals Limited | Wholesale & retail | 1982 |
| Stort Dog Walking Solutions Ltd | Other services | 2022 |
| Stort Living Ltd | Real estate | 2019 |
| Stort View Court Ltd | Real estate | 2023 |
| Stortford Glass Centre Limited | Wholesale & retail | 1985 |
| Stortford Gymnastics Club | Arts & recreation | 2017 |
| Stortford Music Festival C.I.C. | Arts & recreation | 2010 |
| Stortford Property Ltd | Real estate | 2022 |
| Strategic Mentoring Ltd | Education | 2019 |
| Stratification Ltd | Information & communication | 2016 |
| Streat Treats Limited | Hospitality | 2023 |
| Stuarts (Bishops Stortford) Management Company Limited | Real estate | 2002 |
| Sunnyfields Education Services Ltd | Education | 2024 |
| Sunx Marketing Ltd | Information & communication | 2022 |
| Surecare Residential Ltd | Health & social care | 2008 |
| Surefix Crew Limited | Construction | 2025 |
| SW Walks Limited | Other services | 2019 |
| Swan Street Management Company Limited | Households | 2019 |
| Sweet Hustle Ltd | Hospitality | 2023 |
| Swso Productions Limited | Arts & recreation | 2019 |
| Sympetrus Ltd | Professional & scientific | 2017 |
| SYN2GEN Limited | Professional & scientific | 2009 |
| Synergy Dance Championships Limited | Arts & recreation | 2023 |
| T. J Barr Interiors Limited | Construction | 2013 |
| T.F. Interiors Limited | Construction | 2004 |
| TAG Aviation (Stansted) Ltd | Manufacturing | 2007 |
| Tallent and Ryan Ltd | Administrative & support | 2020 |
| Tandi Sprinklers LLP | | 2016 |
| Tatchco Ltd | Professional & scientific | 2014 |
| Tavent Limited | Construction | 2025 |
| TDM Franchise Limited | Wholesale & retail | 2018 |
| Technical Press Supplies Limited | Manufacturing | 1998 |
| Tees Financial Limited | Financial services | 2001 |
| Tees House Management Company Limited | Professional & scientific | 2015 |
| Temah Consulting Limited | Professional & scientific | 2012 |
| Templeman & Harris Limited | Health & social care | 2002 |
| Tetrarchy Limited | Other services | 2025 |
| TFT Production Ltd | Administrative & support | 2026 |
| THE Art Buyer Ltd | Wholesale & retail | 2016 |
| THE Artbuying Company Limited | Professional & scientific | 2008 |
| THE Barn Corporation Limited | Hospitality | 2003 |
| THE Beautiful Ugley Chequers Limited | Hospitality | 2009 |
| THE Chicken Hatch Limited | Hospitality | 2018 |
| THE Digital Pocahontas Limited | Arts & recreation | 2018 |
| THE Flying Seagull Project | Arts & recreation | 2013 |
| THE Horse & Country Store Limited | Professional & scientific | 1985 |