| Smart Fish Bar (Exwick) Ltd | Hospitality | 2024 |
| Smart Heating Services Ltd | Professional & scientific | 2015 |
| Smart Radiology Ltd | Health & social care | 2020 |
| Smart System AV Ltd | Construction | 2020 |
| Smart Trade Limited | Information & communication | 1997 |
| Smart Works (SW) Ltd | Administrative & support | 2008 |
| Smarteco Living Ltd | Real estate | 2022 |
| Smarter Property Builders Limited | Construction | 2024 |
| Smarter Property Consultancy Limited | Real estate | 2024 |
| Smarti Environmental Holdings Limited | Financial services | 2023 |
| Smarti Environmental Limited | Professional & scientific | 2014 |
| Smartmove Residences Ltd | Real estate | 2025 |
| Smarton Limited | Extraterritorial | 2012 |
| Smartrex Development Limited | Wholesale & retail | 2010 |
| Smashem Limited | Construction | 2023 |
| SMC (Exeter) Limited | Wholesale & retail | 1999 |
| SMC UN- Limited | Information & communication | 2025 |
| Smha Management Limited | Real estate | 2024 |
| SMI Properties Limited | Real estate | 2009 |
| Smik Distribution Ltd | Wholesale & retail | 2022 |
| Smilover Limited | Health & social care | 2026 |
| Smith and Sons Construction Ltd | Construction | 2004 |
| SMK Services (South West) Ltd | Construction | 2015 |
| Smkd Foods UK Ltd | Manufacturing | 2025 |
| Smod Properties Ltd | Real estate | 2023 |
| Smoke Hub Distribution Limited | Administrative & support | 2023 |
| Smokehub V2 Limited | Administrative & support | 2024 |
| Smoker and the Bandit Ltd | Hospitality | 2023 |
| Smooth Peach Ltd | Other services | 2026 |
| SMSL1 Limited | Energy | 2016 |
| SMSL2 Limited | Energy | 2016 |
| SMSL3 Limited | Energy | 2016 |
| SMSL4 Limited | Energy | 2016 |
| SMT Motors Ltd | Wholesale & retail | 2024 |
| Smugglers (Milford on Sea) Ltd | Hospitality | 2022 |
| SMV Commercials Limited | Wholesale & retail | 2009 |
| SMW (SW) Ltd | Hospitality | 2021 |
| Snack Box (Devon) Ltd | Hospitality | 2024 |
| Snag That Ltd | Construction | 2011 |
| Snap Automotive Limited | Wholesale & retail | 2021 |
| Snap Bidco Limited | Financial services | 2022 |
| Snap Midco Limited | Financial services | 2022 |
| Snapdragon Property Holdings Ltd | Real estate | 2022 |
| Snapshot (SW) Limited | Real estate | 2023 |
| Snne Ltd | Manufacturing | 2018 |
| Snoot Ltd | Information & communication | 2022 |
| Snow and Paddles Ltd | Administrative & support | 2022 |
| Snow Medical Ltd | Health & social care | 2019 |
| Snowdon Energy Limited | Energy | 2012 |
| Snowshoes Media Ltd | Information & communication | 2004 |
| SO Simple Baits Limited | Manufacturing | 2024 |
| SO, Let’S Talk Ltd | Information & communication | 2017 |
| Soar Mill Ltd | Other services | 2025 |
| Soby Mews Management Company Limited | Households | 2017 |
| Social Enterprise Mark CIC | Other services | 2010 |
| Socially Tuned Limited | Professional & scientific | 2013 |
| Sods Ltd | Professional & scientific | 2020 |
| Software Entity Limited | Information & communication | 1995 |
| Sofyn Connect Ltd | Transport & logistics | 2026 |
| Sofyn Express Ltd | Transport & logistics | 2026 |
| Sofyn Logistics Ltd | Construction | 2025 |
| Soil Property Investments Limited | Real estate | 2025 |
| SOL Invictus Limited | Other services | 2025 |
| Solace INT Ltd | Professional & scientific | 2024 |
| Solagen Limited | Manufacturing | 2001 |
| Solaris Outdoor Ltd | Wholesale & retail | 2026 |
| Solidarity IT Ltd | Information & communication | 2016 |
| Solis Outdoor Living Ltd | Manufacturing | 2025 |
| Sollus Compliance Services Limited | Water & waste | 2025 |
| Sollus Solutions Limited | Professional & scientific | 2022 |
| Solnet Group UK Limited | Construction | 2025 |
| Solomons Farm Ltd | Agriculture & fishing | 2024 |
| Solstice (Exeter) Ltd | Transport & logistics | 2015 |
| Solstice Recruitment Ltd | Administrative & support | 2017 |
| Solution Focused Therapy and Professional Development South West Limited | Health & social care | 2022 |
| Solutionsfd Ltd | Professional & scientific | 2022 |
| Soluxe Ltd | Construction | 2019 |
| Solve-It Southwest Limited | Information & communication | 2004 |
| Somboon Ltd | Wholesale & retail | 2015 |
| Somerset Building & Development Limited | Construction | 2011 |
| Somerset Construction Training (Grants) Ltd | Administrative & support | 2013 |
| Somerset Construction Training Limited | Administrative & support | 2008 |
| Somerset County Cars Limited | Wholesale & retail | 2001 |
| Somerset Education Alliance Ltd | Administrative & support | 2022 |
| Somerset Lower Limb Limited | Health & social care | 2019 |
| Somerset Plant Services Ltd | Manufacturing | 2019 |
| Sometimes Therapy Services Ltd | Education | 2026 |
| Sonador Ltd | Real estate | 2019 |
| SONNET18 Ltd | Professional & scientific | 2026 |
| Sons Real Estate Ltd | Real estate | 2021 |
| Sophie Chestnut Ltd | Wholesale & retail | 2024 |
| Sophie Mary Aesthetics Ltd | Other services | 2025 |
| SOS Awareness Limited | Education | 2023 |
| SOS Global | Education | 2008 |
| SOS Roofing Ltd | Construction | 2025 |
| Soska Properties Ltd | Real estate | 2024 |
| Soulwindow Limited | Health & social care | 2023 |
| Sound Events Ltd | Administrative & support | 2010 |
| Sound Gallery CIC | Manufacturing | 2007 |
| Soup Trader Ltd | Wholesale & retail | 2006 |