| Sheval Inns Limited | Hospitality | 2006 |
| SHI Golden China Ltd | Hospitality | 2022 |
| Shields Healthcare Advisory Limited | Public administration | 2015 |
| Shift Vending Ltd | Wholesale & retail | 2024 |
| Shigooinvestment Ltd | Construction | 2016 |
| Shin Shin Aikido Ltd | Other services | 2024 |
| Shine & Rise Ltd | Extraterritorial | 2022 |
| Shine RAD Ltd | Health & social care | 2023 |
| Shining Star Hand Car Wash Ltd | Administrative & support | 2017 |
| Shiny Wash Ltd | Administrative & support | 2023 |
| Shiplink Ltd | Administrative & support | 2024 |
| Shippey Consultants Ltd | Water & waste | 2015 |
| Shirlden Homes Limited | Real estate | 2022 |
| Shobrook & Company Ltd. | Real estate | 2002 |
| Shobrook Auctions Ltd. | Administrative & support | 2002 |
| Shobrook Management Ltd. | Real estate | 2002 |
| SHOP2U Ltd | Wholesale & retail | 2024 |
| SHOP4MUM Ltd | Information & communication | 2019 |
| Shopfitting by SWS Ltd | Construction | 2010 |
| Shore Building Services Ltd | Manufacturing | 2017 |
| Shore Side Pursers Ltd | Information & communication | 2019 |
| Shore Thing Estates Ltd | Real estate | 2023 |
| Shore Thing Property Investments Ltd | Real estate | 2023 |
| Shore Thing Property Management Limited | Hospitality | 2026 |
| Shorepoint Self Management Ltd | Households | 2012 |
| Short Term Accommodation Plymouth Ltd | Real estate | 2018 |
| Shortflow Plumbing and Heating Limited | Construction | 2015 |
| Shortridge Management Limited | Households | 2024 |
| Shot Construction Ltd | Construction | 2019 |
| Shred Comps Limited | Arts & recreation | 2024 |
| Shred OR Dead Ltd | Hospitality | 2018 |
| Shrimpy Limited | Hospitality | 2014 |
| SI Developments Ltd | Real estate | 2023 |
| SI Fuels Ltd | Wholesale & retail | 2018 |
| Siam Thai Takeaway Ltd | Hospitality | 2025 |
| Sicranium Ltd | Wholesale & retail | 2018 |
| Siddons Scaffolding Services Limited | Construction | 2025 |
| Sidewinder Holidays Ltd | Real estate | 2022 |
| Sidrim Ltd | Wholesale & retail | 2020 |
| Sigma Doors and Shutters Limited | Construction | 2022 |
| Sigma Precision Engineering Ltd. | Manufacturing | 2002 |
| Sigmapoint Resources Limited | Professional & scientific | 2023 |
| Signature Commercial & Construction Ltd | Administrative & support | 2025 |
| Signature Strawberries Ltd | Hospitality | 2021 |
| Signature Streetwear Ltd | Wholesale & retail | 2024 |
| Significant Print and Design Limited | Manufacturing | 2010 |
| Significant Signs Limited | Manufacturing | 2001 |
| SIL Plastering Projects Limited | Extraterritorial | 2022 |
| Silent Success Ltd | Professional & scientific | 2018 |
| Silent Successes Ltd | Extraterritorial | 2020 |
| Silhouette Research & Technology Limited | Information & communication | 2010 |
| Silicon Sensing Products (UK) Limited | Manufacturing | 1998 |
| Silicon Sensing Systems Limited | Manufacturing | 1998 |
| Silks Civil Engineering Ltd | Construction | 2025 |
| Siloet Ltd | Information & communication | 2014 |
| Silver Dragon SW Ltd | Hospitality | 2024 |
| Silver Lining Services Ltd | Health & social care | 2025 |
| Silver Mountain Cards Ltd | Wholesale & retail | 2025 |
| Silver Republic Ltd | Extraterritorial | 2025 |
| Silver Security London Ltd | Administrative & support | 2018 |
| Simon Barnes Driving School Limited | Education | 2026 |
| Simon Chaudoir DOP Limited | Professional & scientific | 2026 |
| Simon Coleridge Orthopaedics Ltd | Health & social care | 2009 |
| Simon Gillbard Construction Ltd | Construction | 2022 |
| Simon Invest Golf Limited | Arts & recreation | 2017 |
| Simon M S Mayhew Independent Financial Adviser Limited | Financial services | 2006 |
| Simon Plend Limited | Information & communication | 2016 |
| Simon Pope Consulting Limited | Information & communication | 2008 |
| Simon Russell Studio Ltd | Professional & scientific | 2020 |
| Simpel Wetsuits Limited | Financial services | 2023 |
| Simple Solar (SW) Ltd | Construction | 2021 |
| Simplecrumb Ltd | Information & communication | 2017 |
| Simply Cleaning Essex Ltd | Administrative & support | 2023 |
| Simply Construction (SW) Ltd | Construction | 2024 |
| Simply Kitchens UK Limited | Wholesale & retail | 2009 |
| Simply Lloyd Limited | Wholesale & retail | 2019 |
| Simply Maintenance (SW) Ltd | Construction | 2022 |
| Simply Safe Storage Ltd | Construction | 2026 |
| Simply Spotless by Gemma Stephens Ltd | Administrative & support | 2026 |
| Simply Translation Limited | Professional & scientific | 2010 |
| Simply Wealth Ltd. | Professional & scientific | 2010 |
| Sims Accommodation Limited | Hospitality | 2026 |
| Sims Brothers (Plymouth) Limited | Construction | 2003 |
| Sims Financial Management Ltd | Financial services | 2016 |
| Sinclair House Residents Company Limited | Households | 2002 |
| Sionis Launchx Limited | Professional & scientific | 2019 |
| Sionis Ltd | Information & communication | 2015 |
| SIR FIX a Lock Limited | Manufacturing | 2011 |
| Siraj Sons Limited | Hospitality | 2019 |
| SIS Engineering Services Limited | Professional & scientific | 2015 |
| Sister Snacks Limited | Hospitality | 2026 |
| Sister Vivi Limited | Wholesale & retail | 2023 |
| Sisters Talk CIC | Education | 2025 |
| Sisua Group Limited | Hospitality | 2026 |
| SITES2DAY Ltd | Information & communication | 2026 |
| Sixteen Management Limited | Households | 2006 |
| Sizzling Grill Barbican Ltd | Hospitality | 2018 |
| SJ Murphy Group Ltd | Financial services | 2025 |
| SJ Renovation and Maintenance Limited | Construction | 2024 |
| SJC Specialised Electrical Services Ltd | Manufacturing | 2023 |