| S. Notaro Limited | Construction | 1965 |
| S.A. Webber Limited | Construction | 2019 |
| S.J&I.S Ltd | Real estate | 2025 |
| S.L Automotive (SW) Ltd | Wholesale & retail | 2025 |
| S.P.F.Associates Limited | Professional & scientific | 1999 |
| S.Roberts & Son(Bridgwater)Limited | Transport & logistics | 1962 |
| SA Saray Ltd | Hospitality | 2021 |
| Saanvi Investments (UK) Ltd | Real estate | 2024 |
| Sabelwood (Block Management) Limited | Real estate | 2013 |
| Sabena Limited | Wholesale & retail | 2024 |
| Safe Mobile Solutions (Devizes) Ltd | Wholesale & retail | 2025 |
| Safe Moving & Handling Limited | Wholesale & retail | 2015 |
| Safer Environment Limited | Professional & scientific | 2022 |
| Safety at Smallmoor CIC | Administrative & support | 2024 |
| Sage and Thyme Ltd | Professional & scientific | 2018 |
| Sahin & Falco Limited | Hospitality | 2022 |
| Sakant Construction and Solutions Limited | Construction | 2015 |
| Salant Ltd | Administrative & support | 2002 |
| Sally's School of Motoring Limited | Administrative & support | 2006 |
| Salter Civils & Groundworks Ltd | Construction | 2021 |
| Salter Plant Services Limited | Manufacturing | 2023 |
| Salter Properties SW Ltd | Households | 2026 |
| SAM and Kate Properties Ltd | Real estate | 2025 |
| Sammi Property Limited | Real estate | 2024 |
| Samson Landscaping Ltd | Administrative & support | 2017 |
| Samuel Thompson Corporate Limited | Professional & scientific | 2012 |
| Samuel Thompson Property Limited | Hospitality | 2025 |
| Samuel Whittlesea Limited | Financial services | 2015 |
| Sam’S Fresh Kitchen Ltd | Hospitality | 2022 |
| Sanctuary Stud Ltd | Agriculture & fishing | 2019 |
| Sandals for Edom Limited | Health & social care | 2016 |
| Sandpaper Leadership Limited | Professional & scientific | 2018 |
| Sarah Navoy ND Services Ltd | Health & social care | 2025 |
| SAS Decorators Limited | Construction | 2018 |
| SAS Motorcycle Tours Ltd | Administrative & support | 2026 |
| SAS Rendering Limited | Construction | 2025 |
| Sassy Sorority Limited | Wholesale & retail | 2026 |
| Saunders Advanced Allied Health Professionals Limited | Health & social care | 2024 |
| Savannah Property Services Ltd | Construction | 2021 |
| Saving Santa Claus Limited | Information & communication | 2017 |
| Saxon LEA Drainage Services Limited | Households | 1997 |
| Saxons Block Management Limited | Real estate | 2022 |
| Saxons Safety Services Ltd | Professional & scientific | 2024 |
| SBC Contracting Ltd | Transport & logistics | 2019 |
| SBM Secretarial Services Ltd | Real estate | 2025 |
| Sbmc Property Group Ltd | Real estate | 2026 |
| SBT Solutions Ltd | Manufacturing | 2025 |
| Scaff West Rigging Ltd | Information & communication | 2015 |
| Scale Your Trade Limited | Other services | 2019 |
| Scan Film OR Store Holdings Limited | Financial services | 2024 |
| Scan Film OR Store Limited | Administrative & support | 2009 |
| Scapex Grounds Maintenance Ltd | Administrative & support | 2024 |
| SCC Private Members Ltd | Other services | 2020 |
| SCG Fencing Limited | Construction | 2014 |
| Scorpion Dynamics Ltd | Professional & scientific | 2014 |
| Scribe Lounge Pro Ltd | Information & communication | 2020 |
| SD Fleet Services Ltd | Transport & logistics | 2026 |
| SDI Property Holdings Limited | Real estate | 2025 |
| Searle Compliance Solutions Limited | Administrative & support | 2013 |
| Sears Developments Limited | Construction | 2015 |
| Sears Real Estate Limited | Real estate | 2018 |
| Seasonal Attractions Ltd | Hospitality | 2023 |
| Seawide Consulting Limited | Professional & scientific | 2000 |
| Seccro Limited | Professional & scientific | 2018 |
| Second Swing Golf Ltd | Wholesale & retail | 2025 |
| Secretariat Support Solutions Ltd | Professional & scientific | 2018 |
| Secureproject Property Management Limited | Households | 1986 |
| Sedgemoor Accountancy Services Limited | Professional & scientific | 2009 |
| Sedgemoor Community Connector CIC | Health & social care | 2025 |
| Sedgemoor Community Transport | Transport & logistics | 2003 |
| Sedgemoor Fire Prevention Limited | Administrative & support | 2002 |
| Sedgemoor Fire Protection Limited | Administrative & support | 2018 |
| Sedgemoor FM CIC | Information & communication | 2022 |
| Sedgemoor Group Ltd | Hospitality | 2016 |
| Sedgemoor Property Investments Ltd | Real estate | 2025 |
| Sedgemoor Solutions Limited | Professional & scientific | 2023 |
| Sedgemoor Vintage Club Limited | Other services | 1995 |
| Sedgemoors Lamb Lane Management Company Limited | Households | 2007 |
| Sedgmoore Doggie Splash & Daycare Limited | Other services | 2021 |
| Seine Paris Ltd | Wholesale & retail | 2013 |
| Self Assessment Returns Ltd | Professional & scientific | 2022 |
| Semmelweis TV Series Ltd | Arts & recreation | 2023 |
| Seren Skills Network Ltd | Professional & scientific | 2019 |
| Servicesense Ltd | Information & communication | 2024 |
| Seventy Seven D Limited | Households | 2018 |
| Severn Delta Limited | Manufacturing | 2001 |
| Sewells Consulting Limited | Information & communication | 2015 |
| SGL PUB Management Ltd | Hospitality | 2025 |
| SH Operations Limited | Professional & scientific | 2026 |
| Shamz Peri Peri Ltd | Hospitality | 2024 |
| Shapwick Community Playing Field Company Limited | Arts & recreation | 2010 |
| Sharpak Bridgwater Limited | Manufacturing | 2010 |
| Shaun LEE Ltd | Construction | 2019 |
| Shaun Vincent General Building Contractors Ltd | Construction | 2011 |
| Shavarath Limited | Wholesale & retail | 2013 |
| Shearing Building Services Ltd | Other services | 2012 |
| Shelbak Ltd | Real estate | 2025 |
| Sheppard Industries Limited | Professional & scientific | 2014 |
| Shepton Estates Limited | Professional & scientific | 2013 |
| Shibuya Style Ltd | Wholesale & retail | 2025 |