| Shebahn Limited | Administrative & support | 2026 |
| Shed Loads of FUN Limited | Education | 2016 |
| Sheehy Visuals Ltd | Information & communication | 2026 |
| Sheepdip Media Limited | Transport & logistics | 2012 |
| Sheldon Peever Studio Limited | Professional & scientific | 2015 |
| Sheldrake (HTH) Services Limited | Health & social care | 2024 |
| Shelf Names Limited | Extraterritorial | 2012 |
| Shenly Food Ltd | Other services | 2019 |
| Shepard Price Limited | Professional & scientific | 2000 |
| Shepheard Industrial Ltd | Manufacturing | 2022 |
| Shepheard Property Limited | Real estate | 2019 |
| Shepherd's Landscape and Garden Services Ltd | Administrative & support | 2019 |
| Sheraton Blinds (Holdings) Limited | Professional & scientific | 2013 |
| Sheraton Blinds Limited | Manufacturing | 1977 |
| Sheri Trans Ltd | Transport & logistics | 2021 |
| Sheriah Properties Ltd | Real estate | 2026 |
| Sherpa Environmental Ltd | Water & waste | 2014 |
| Sherrards Solicitors LLP | | 2010 |
| Shields Music & Touring Limited | Information & communication | 2025 |
| Shining Bright Productions Limited | Information & communication | 2022 |
| Shire Park Limited | Real estate | 1986 |
| Shire Reeve Limited | Professional & scientific | 2016 |
| Shire School of Motoring Limited | Education | 2011 |
| Shiredrive Ltd | Education | 1994 |
| Shivanj Ltd | Real estate | 2022 |
| SHM Fire Consultancy Limited | Public administration | 2025 |
| Shojin Financial Services Limited | Financial services | 2015 |
| Shojin Property Partners Limited | Financial services | 2015 |
| Sholls UK Ltd | Professional & scientific | 2020 |
| Shona Davies Ltd | Professional & scientific | 2019 |
| Shona Ferguson Consultancy Ltd | Professional & scientific | 2019 |
| Shop Smaart Ltd | Extraterritorial | 2023 |
| Shop West One Limited | Wholesale & retail | 2017 |
| Shoreditch Studios Limited | Other services | 2006 |
| Shoroma Global Limited | Health & social care | 2021 |
| Shortpause Limited | Arts & recreation | 1996 |
| Show HOW Ltd | Professional & scientific | 2013 |
| Showtime DJS & Events Ltd | Arts & recreation | 2025 |
| Shree Varahi Ltd | Real estate | 2023 |
| Shrink Wrapped Developments Ltd | Real estate | 2025 |
| Shrirama Ltd | Hospitality | 2024 |
| Shrublands Close Limited | Households | 1995 |
| Shrublands Management Limited | Households | 2007 |
| Shudhco. Ltd | Wholesale & retail | 2026 |
| SHY and Mighty Ltd | Administrative & support | 2016 |
| Siam Cooking Ltd | Hospitality | 2019 |
| Sianswimwear Limited | Manufacturing | 2014 |
| Sid's Art House Ltd | Education | 2026 |
| Sidelight AI Limited | Information & communication | 2025 |
| Sidequest Apparel Ltd | Wholesale & retail | 2021 |
| Sidequest TGC Ltd | Wholesale & retail | 2021 |
| Siena Transform Limited | Professional & scientific | 2024 |
| Sigil Initiative Ltd | Information & communication | 2018 |
| Sigma Medical Supplies Ltd | Manufacturing | 2019 |
| Signal House Studios Ltd | Information & communication | 2025 |
| Signal Void Radiology Ltd | Professional & scientific | 2025 |
| Signature Collective Ltd | Manufacturing | 2025 |
| Signature Executive Ltd | Professional & scientific | 2026 |
| Signature House Management Harpenden Limited | Real estate | 2024 |
| Silence VC Nominees Limited | Financial services | 2023 |
| Silkside Capital Limited | Real estate | 2021 |
| Silver Angold Limited | Manufacturing | 2024 |
| Silver Business Consulting Limited | Professional & scientific | 2009 |
| Silver Ferret Property Ltd | Real estate | 2025 |
| Silver Ibex Limited | Professional & scientific | 2026 |
| Silverfern Gardening Limited | Other services | 2007 |
| Silverjack Limited | Administrative & support | 2018 |
| Silversurfers Limited | Information & communication | 2012 |
| Silvery Moon (Adsar) Limited | Administrative & support | 2017 |
| Simetria Limited | Construction | 2019 |
| Simon David Edward Lucas Ltd | Extraterritorial | 2022 |
| Simon Jarratt Photography Limited | Professional & scientific | 2015 |
| Simon Knight Architects Ltd | Professional & scientific | 2021 |
| Simon L Taylor Limited | Professional & scientific | 2011 |
| Simon Lane Remastered (SLR) Ltd | Wholesale & retail | 2024 |
| Simon Phipps Associates Ltd | Professional & scientific | 2012 |
| Simon Tyers TV Limited | Arts & recreation | 2005 |
| Simon Wright Consulting Ltd | Professional & scientific | 2021 |
| Simon Wright Investments Limited | Financial services | 2026 |
| Simple Savings Ltd | Financial services | 1999 |
| SIMPLEIT4U Ltd | Information & communication | 2018 |
| Simplex Thinking Ltd | Information & communication | 2023 |
| Simplifysafety Ltd | Professional & scientific | 2012 |
| Simply Aura Ltd | Professional & scientific | 2006 |
| Simply Bathrooms D.A. Limited | Construction | 2016 |
| Simply Solar Installers Ltd | Construction | 2026 |
| Simply YG Ltd | Professional & scientific | 2019 |
| Sinaton Group Ltd | Construction | 2025 |
| Sirface Graphics Ltd | Professional & scientific | 2013 |
| Sirrah Consulting Limited | Other services | 2018 |
| Sirti Trading and Consulting Ltd | Wholesale & retail | 2020 |
| Sisk Consolidated Investments Limited | Construction | 1989 |
| Sisters Stationery Ltd | Wholesale & retail | 2014 |
| Sitewise Training Limited | Education | 2025 |
| Sitlab Technology UK Limited | Information & communication | 2020 |
| Sixth Millennium Nominees Limited | Financial services | 2023 |
| Sixty HZ Ltd | Construction | 2025 |
| SJ Innovations Limited | Information & communication | 2021 |
| SJ Steel & Timber Frame Ltd | Construction | 2019 |
| SJ Trading Herts Limited | Wholesale & retail | 2023 |