| Sandys Deliveries Ltd | Transport & logistics | 2025 |
| Sandysike Management Company Limited | Households | 2006 |
| Sandysike Pumping Station Limited | Real estate | 2010 |
| Sangha Body Heart Mind Ltd | Health & social care | 2025 |
| Saniclean Limited | Administrative & support | 2016 |
| Sanitiglow Ltd | Administrative & support | 2025 |
| Sannas Limited | Hospitality | 2016 |
| Santo MIL Properties Ltd | Real estate | 2023 |
| Santrexx Limited | Information & communication | 2025 |
| Sapientia Holdings Limited | Financial services | 2024 |
| Sarah AMY Story Associates Limited | Administrative & support | 2012 |
| Sarah Linnett Childcare (Carlisle) Ltd | Education | 2021 |
| Sare Properties Limited | Construction | 2006 |
| Sark Agri Limited | Administrative & support | 2024 |
| Sarkaar Trading Ltd | Wholesale & retail | 2023 |
| Satu Interiors Limited | Wholesale & retail | 2001 |
| Saturn Four Media Ltd | Professional & scientific | 2025 |
| SAW Taverns Limited | Hospitality | 2026 |
| Sawyers Windows & Construction Ltd | Construction | 2009 |
| Saxon Pazey Ltd | Wholesale & retail | 2023 |
| SB Properties (Cumbria) Ltd | Real estate | 2020 |
| SBC Diamond Drilling Limited | Construction | 2006 |
| SBK Groundworks Ltd | Construction | 2025 |
| SC & Sons Electrical Services Ltd | Construction | 2025 |
| SC Fabrication (North) Limited | Manufacturing | 2021 |
| Scafell Hotel Limited | Hospitality | 1950 |
| Scafell Roofing Limited | Construction | 2018 |
| Scaffolding Solutions (Carlisle) Ltd | Construction | 2016 |
| Scai Angels Ltd | Hospitality | 2023 |
| Scaleby Estates Limited | Real estate | 2025 |
| Scalesceugh Gardens (Carleton) Management Company Limited | Households | 2001 |
| Scallow Farm Limited | Hospitality | 2025 |
| Scenicdowntownhideaways Ltd | Hospitality | 2024 |
| Scholars Green (Distington) Management Limited | Households | 2013 |
| School Close (Raughton Head) Management Company Limited | Households | 2022 |
| Science for Sustainable Agriculture | Information & communication | 2022 |
| Scorpio Consumer Electronics Limited | Wholesale & retail | 2023 |
| Scotby Consulting Limited | Professional & scientific | 2021 |
| Scotby Grange Management Limited | Households | 2007 |
| Scotby Green Steading Management Company Limited | Households | 2023 |
| Scotby Grove (Scotby) Management Company Limited | Real estate | 2025 |
| Scotnic Holdings Limited | Financial services | 2007 |
| Scott & Cain Ltd | Real estate | 2024 |
| Scott Advisory Group Limited | Professional & scientific | 2025 |
| Scott Consumer Finance Limited | Financial services | 2018 |
| Scott Motor Finance Ltd | Financial services | 2019 |
| Scott Self Storage (Cumbria) Limited | Real estate | 1984 |
| Scott Self Storage Limited | Financial services | 2024 |
| Scott X Limited | Wholesale & retail | 2018 |
| Scotts Taxis Services Ltd | Transport & logistics | 2022 |
| Scowie Holdings Limited | Professional & scientific | 2015 |
| Scrap the 9 to 5 Ltd | Administrative & support | 2016 |
| Scrutineers & Associates Limited | Professional & scientific | 2013 |
| SD Executive Ltd | Transport & logistics | 2023 |
| Sean C Reed Limited | Real estate | 2015 |
| Sean Crilley Funeral Directors Limited | Other services | 2018 |
| Sean Tyrrell Roofing Limited | Construction | 2021 |
| Search Apparel Ltd | Wholesale & retail | 2018 |
| Seat Hill | Agriculture & fishing | 2011 |
| Seavor 1984 Limited | Financial services | 2026 |
| Seavor Limited | Professional & scientific | 2014 |
| Sebergham Motors Limited | Wholesale & retail | 2022 |
| Sebergham Services Limited | Wholesale & retail | 2003 |
| Secnet Design and Consultancy Limited | Information & communication | 2024 |
| Second Potato Ltd | Real estate | 2018 |
| Secret Garden at Maceys Ltd | Other services | 2016 |
| Segand Property Ltd | Real estate | 2024 |
| Sellittrade.Com Limited | Wholesale & retail | 2018 |
| Selshaw Investments Ltd | Real estate | 2013 |
| Selshaw Property Ltd | Real estate | 2011 |
| Sensible Choice IT Limited | Information & communication | 2011 |
| Sentinell Security Limited | Administrative & support | 2025 |
| SEP Construction Limited | Construction | 2012 |
| Sequrit Limited | Information & communication | 2009 |
| Sesar Property Investments Ltd | Real estate | 2020 |
| Settle & Carlisle Railway Properties Limited | Wholesale & retail | 1999 |
| Seven Spencer Holdings Ltd | Real estate | 2024 |
| SEVENTY3 Automotive Limited | Wholesale & retail | 2022 |
| SEW the Reel Ltd | Manufacturing | 2020 |
| Sewing Solutions Carlisle Ltd | Other services | 2026 |
| SF Force Limited | Other services | 2014 |
| Sfel Bluebell Limited | Energy | 2022 |
| Sfel Burgh Limited | Extraterritorial | 2022 |
| Sfel Four Limited | Energy | 2023 |
| Sfel One Limited | Energy | 2023 |
| Sfel Scott Limited | Energy | 2022 |
| Sfel Three Limited | Extraterritorial | 2023 |
| Sfel Two Limited | Energy | 2023 |
| Sfel Whistleberry Limited | Energy | 2022 |
| Sfel Willow Limited | Energy | 2022 |
| Sfel Windsor Limited | Extraterritorial | 2022 |
| SFM Deliveries Ltd | Transport & logistics | 2021 |
| Shaarawy Ltd | Transport & logistics | 2025 |
| Shad Style Ltd | Other services | 2024 |
| Shaddon Mill Limited | Households | 2005 |
| Shadreck Makosa Limited | Health & social care | 2024 |
| Shagas IT Ltd | Information & communication | 2026 |
| Shaha Restaurant (Carlisle) Ltd | Hospitality | 2025 |
| Shaha Restaurant Ltd | Hospitality | 2017 |
| Shahryar Sales Services Ltd | Wholesale & retail | 2023 |