| SC Conversions Ltd | Manufacturing | 2013 |
| SC General Construct Ltd | Construction | 2018 |
| SC Paint Specialists Ltd | Construction | 2017 |
| SC Pet Services Limited | Agriculture & fishing | 2025 |
| Scafftec Ltd | Construction | 2017 |
| Scale UP Software Ltd | Professional & scientific | 2025 |
| Scarletpl Ltd | Manufacturing | 2013 |
| Scarpin Solutions Ltd | Extraterritorial | 2020 |
| SCC (Cornwall) Limited | Real estate | 2010 |
| SCC (South West) Limited | Real estate | 2000 |
| SCC Commercials Ltd | Other services | 2017 |
| SCD Comps Limited | Arts & recreation | 2026 |
| SCE Electrical Services Limited | Construction | 2010 |
| Scenic Ltd | Real estate | 2025 |
| Scentials Fragrances Ltd | Wholesale & retail | 2026 |
| Schock German Quality Built in Ltd | Extraterritorial | 2009 |
| School House (Devon) Limited | Hospitality | 2017 |
| Schottel UK Ltd | Wholesale & retail | 2025 |
| Science Pro Consulting Ltd | Professional & scientific | 2024 |
| SCJ Futures Ltd | Professional & scientific | 2015 |
| Scoble & SON Limited | Construction | 2022 |
| Scooby-Dees Limited | Other services | 2009 |
| Scorpion Technologies Ltd | Information & communication | 2026 |
| Scott Developments (SW) Ltd | Real estate | 2026 |
| Scott Moore Plastering Limited | Construction | 2021 |
| Scott Rennie Plumbing and Heating Ltd | Construction | 2024 |
| Scowcroft Lettings Ltd | Real estate | 2024 |
| SCR Consult Ltd | Professional & scientific | 2021 |
| Scrapavehicle.Co.Uk Limited | Wholesale & retail | 2026 |
| Scratchperfect Limited | Construction | 2014 |
| Scribbling Media Limited | Arts & recreation | 2016 |
| Scrubhub SW Ltd | Administrative & support | 2024 |
| Scsw Solutions Ltd | Administrative & support | 2024 |
| Scutum Digital Ltd | Administrative & support | 1996 |
| Scutum South West Limited | Administrative & support | 1998 |
| Scylla Reef Limited | Arts & recreation | 2004 |
| SD Innovations Shaun Ltd | Construction | 2025 |
| SD South West Limited | Real estate | 2023 |
| SD Systems Ltd | Information & communication | 2019 |
| SDE Scaffolding Ltd | Construction | 2025 |
| SDG Group Limited | Construction | 2019 |
| Sdmurphy Electrical Limited | Professional & scientific | 2017 |
| SDS Civils (SW) Ltd. | Construction | 2016 |
| Sea Breeze Salcombe Limited | Administrative & support | 2023 |
| Sea Major Limited | Professional & scientific | 2016 |
| Sea to Shore Ltd | Administrative & support | 2023 |
| Sea View Barber Ltd | Other services | 2024 |
| Sea View Terrace Management Company Limited | Extraterritorial | 1995 |
| Sea Views Property Ltd | Real estate | 2021 |
| Seabound Estates Limited | Real estate | 2025 |
| Seacrew Ltd | Real estate | 2020 |
| Seal-Corp Ltd | Transport & logistics | 2017 |
| Sealed UP Nottingham Ltd | Administrative & support | 2018 |
| Sealion Futures Limited | Real estate | 2025 |
| Sealsmart Roofing Contractors Ltd | Construction | 2025 |
| Seamoor Property Limited | Real estate | 2024 |
| Seamore Management Company Limited | Households | 2002 |
| Sean Rees Engineering Services Ltd | Construction | 2011 |
| Sean's Tyre Recycling Limited | Water & waste | 2026 |
| Searegs Training Ltd | Education | 2014 |
| Searles Ltd | Real estate | 2016 |
| Seascape Freehold Newquay Ltd | Real estate | 2023 |
| Seascape Management Newquay Limited | Real estate | 2015 |
| Seaside Plumbing and Heating Ltd | Construction | 2024 |
| Seaton Park House Limited | Construction | 2020 |
| SEB Property Group Ltd | Extraterritorial | 2014 |
| Sebastian and Fawn Psychology Ltd | Health & social care | 2022 |
| Seco Group Ltd | Construction | 2024 |
| Seco Holdings Limited | Professional & scientific | 2019 |
| Seco Support Limited | Health & social care | 2019 |
| SECOND2NONE Property Management Services (Salcombe) Limited | Construction | 2018 |
| Secret Level Ltd | Wholesale & retail | 2017 |
| Secsystems Limited | Information & communication | 2023 |
| Sector IT Consultation Ltd | Information & communication | 2026 |
| Secure Open Storage Limited | Real estate | 2012 |
| Secure Storage Solutions (Devon) Ltd | Other services | 2016 |
| Secured Storage Ltd | Transport & logistics | 2019 |
| Securewest International (Risk Management) Limited | Other services | 2000 |
| Security and Communications Systems Ltd | Information & communication | 2012 |
| Security Management South West Limited | Administrative & support | 2005 |
| Security Middle East Ltd | Professional & scientific | 2017 |
| Securtify Ltd | Wholesale & retail | 2026 |
| Seddon Collings LLP | | 2017 |
| Sedgeford Developments Limited | Construction | 1986 |
| Seed of Hope CIC | Health & social care | 2017 |
| Seft Care Limited | Health & social care | 2022 |
| Sekoya Limited | Professional & scientific | 2013 |
| SEL Construction Ltd | Construction | 2019 |
| Selamma Takeaway Ltd | Hospitality | 2025 |
| Select Appliances Ltd | Wholesale & retail | 2002 |
| Select South West Tours Limited | Administrative & support | 2015 |
| Select Vehicle Leasing Limited | Administrative & support | 2012 |
| Select Vending (Wholesale) Limited | Manufacturing | 1998 |
| Selflor Limited | Construction | 2014 |
| Sellaman Ltd | Wholesale & retail | 2026 |
| Selvaleela Limited | Information & communication | 2025 |
| Selwyn Radley Associates Limited | Administrative & support | 2016 |
| Selwyn Stevens International Ltd | Administrative & support | 2016 |
| Sement Bricklaying Contractors Limited | Construction | 2012 |
| Semiology Ltd | Financial services | 2025 |