| Sayat Homes Ltd | Real estate | 2024 |
| Sayno+ Ltd | Arts & recreation | 2024 |
| Sazi Group Ltd | Wholesale & retail | 2025 |
| SB Painting and Decorating Ltd | Construction | 2025 |
| SB Property Power Ltd | Real estate | 2024 |
| SB3 Artist Management Ltd | Professional & scientific | 2023 |
| SBG Thind Investment Ltd | Real estate | 2024 |
| SBS Consulting Inc Ltd | Information & communication | 2010 |
| Scadea Software Solutions Limited | Information & communication | 2021 |
| Scaffnet Ltd | Construction | 2021 |
| Scaffolding in London Ltd | Construction | 2015 |
| Scarlet Cars Ltd | Transport & logistics | 2024 |
| Scarlet Film and TV Services Ltd | Construction | 2012 |
| Scene DEC Ltd | Other services | 2012 |
| Scenic Solutions Ltd | Construction | 2025 |
| Scentsational Flowers Limited | Wholesale & retail | 2015 |
| Scentsational Limited | Wholesale & retail | 2021 |
| School of Eclectic Thought Ltd | Education | 2019 |
| Schweppes Limited | Professional & scientific | 1958 |
| Scientifica-Cook Limited | Manufacturing | 1964 |
| Scot Holdings Ltd | Extraterritorial | 2023 |
| Scott K Construction Ltd | Construction | 2025 |
| Scotten Norlay Associates Limited | Professional & scientific | 2007 |
| Scout Atlas Limited | Administrative & support | 2025 |
| Scovware Limited | Wholesale & retail | 2016 |
| SCR Europe Ltd | Administrative & support | 2023 |
| Scratch Numbers Limited | Professional & scientific | 2026 |
| Screened Personnel Limited | Administrative & support | 2020 |
| SCS Capital Limited | Transport & logistics | 2019 |
| Scubacam Limited | Manufacturing | 2006 |
| Scum Worldwide Ltd | Manufacturing | 2021 |
| SDS Investment Dorset Ltd | Real estate | 2020 |
| SDS Investment Group Ltd | Construction | 2019 |
| Sdsds Limited | Transport & logistics | 2025 |
| Sea Hawk Global (UK) Ltd | Transport & logistics | 2008 |
| Seabeck Limited | Real estate | 2019 |
| Seacarver Limited | Professional & scientific | 2025 |
| Seadragon Technical Services Limited | Real estate | 2005 |
| Seaward Scenic Productions Ltd | Construction | 2023 |
| SEB Professional UK Limited | Wholesale & retail | 1998 |
| Secret Desires Ltd | Wholesale & retail | 2026 |
| Sections Contracting & Trading Limited | Construction | 2010 |
| Secure Advanced Systems Limited | Manufacturing | 2008 |
| Secure Future Consultants Ltd | Administrative & support | 2013 |
| Secure Goods Ltd | Wholesale & retail | 2026 |
| Secure Site (UK) Ltd | Administrative & support | 2003 |
| Secure Site Civil Enforcement Limited | Extraterritorial | 2009 |
| Secure Site Fire & Security Ltd | Other services | 2009 |
| Secure Site Services Ltd | Administrative & support | 2017 |
| Secure Vault Limited | Administrative & support | 2024 |
| Security Technology Group International Ltd | Information & communication | 2015 |
| Sedzmo Tennis Coaching Ltd | Administrative & support | 2012 |
| Seenthis Sales UK Limited | Information & communication | 2020 |
| Sehgal Airport Transfers Ltd | Transport & logistics | 2023 |
| Sehra Quality Consulting Ltd | Information & communication | 2025 |
| Sekhon Building Services Ltd | Construction | 2017 |
| Sekhon Properties Investment Ltd | Real estate | 2019 |
| Selborne Care Limited | Health & social care | 2005 |
| Select Airparks Limited | Hospitality | 2018 |
| Select Delivery Limited | Transport & logistics | 2018 |
| Select House Ltd | Manufacturing | 2020 |
| Select Parking Limited | Other services | 2017 |
| Select School of Dance Ltd | Arts & recreation | 2022 |
| Selectrestaurantgroup Ltd | Hospitality | 2026 |
| Selfora Ltd | Wholesale & retail | 2026 |
| Sellers and Buyers Limited | Wholesale & retail | 2018 |
| Selwyn Care Limited | Health & social care | 1999 |
| Semanticca Ltd | Information & communication | 2019 |
| Send & Receive Worldwide Express UK Limited | Transport & logistics | 2012 |
| Senda Way Ltd | Transport & logistics | 2021 |
| Sensigo Ltd | Manufacturing | 2020 |
| Sensowl Ltd | Wholesale & retail | 2024 |
| Sentry CP Ltd | Real estate | 2025 |
| Sentry HCE Ltd | Information & communication | 2025 |
| SEO Freelancer Ltd | Professional & scientific | 2022 |
| Septemoil Ltd | Transport & logistics | 2010 |
| Serdi (UK) Limited | Wholesale & retail | 1987 |
| Serena Arch Ltd | Extraterritorial | 2022 |
| Serene Home Decor Limited | Wholesale & retail | 2023 |
| Serene Home Stay Ltd | Real estate | 2025 |
| Serene Pahan Limited | Manufacturing | 2024 |
| Serenefy Ltd | Health & social care | 2024 |
| Serenity Lashes Ltd | Other services | 2019 |
| Serenity Solutions Limited | Information & communication | 2003 |
| Services & Solutions Company International Limited | Extraterritorial | 2016 |
| SET Safe Ltd | Information & communication | 2024 |
| Seven & Saint Logistics Limited | Transport & logistics | 2012 |
| Seven at 34 Management Limited | Real estate | 2021 |
| Seven Circle Group Ltd | Administrative & support | 2018 |
| Seven Doors Holdings and Investments Limited | Professional & scientific | 2025 |
| Seventy Seven Surveyors Limited | Professional & scientific | 2020 |
| SEW Motor Company Limited | Wholesale & retail | 2024 |
| Sewise Ltd | Construction | 2019 |
| Seyon Star Limited | Real estate | 2012 |
| SFF Contractors Ltd | Construction | 2026 |
| SFL Holdco Limited | Financial services | 2026 |
| SG & JG Investments Limited | Real estate | 2017 |
| SG Asbestos Ltd | Professional & scientific | 2025 |
| SG Courier & Logistics Limited | Transport & logistics | 2024 |
| SG Mabbs Limited | Information & communication | 2021 |