| SBK Wealth Ltd | Other services | 2018 |
| Sblr Ltd | Construction | 2026 |
| Scareroom Productions Ltd | Arts & recreation | 2024 |
| Scjc Productions Ltd | Information & communication | 2024 |
| Scobberlotcher Limited | Arts & recreation | 2024 |
| Scopelocal Ltd | Information & communication | 2025 |
| Scopi Ltd | Construction | 2018 |
| Scotch Management Ltd | Professional & scientific | 2019 |
| Scott Building Surveyors Limited | Construction | 2003 |
| SCREENS4LESS Limited | Information & communication | 2017 |
| SD Communications Limited | Professional & scientific | 2015 |
| SD Logistics Limited | Transport & logistics | 2026 |
| SDS Decorating Ltd | Construction | 2024 |
| SE Electrical Solutions Ltd | Construction | 2023 |
| SE Renewable Solutions Ltd | Construction | 2025 |
| Seaberjewitt Windows Limited | Construction | 2014 |
| Sealing Solutions Limited | Manufacturing | 1997 |
| Sean Cracknell & SON Limited | Real estate | 2004 |
| Searings Limited | Extraterritorial | 2021 |
| Sears Melvin Ltd | Water & waste | 2025 |
| Sebino Holdings Limited | Real estate | 2021 |
| Seckford Lodges Limited | Extraterritorial | 2014 |
| Second Nature Tree Services Limited | Agriculture & fishing | 2014 |
| Section 6 Publishing Ltd | Information & communication | 2023 |
| Secure Systems Installations Limited | Administrative & support | 2005 |
| Seductivedirect Ltd | Wholesale & retail | 2018 |
| Seex Solutions Limited | Professional & scientific | 2019 |
| Seine Investments Ltd | Construction | 2008 |
| Select Manufacturing Limited | Manufacturing | 1998 |
| Selene Consulting Ltd | Professional & scientific | 2022 |
| Selvapura Ltd | Real estate | 2016 |
| Selwyn Plumbing and Heating Ltd | Construction | 2023 |
| Semadce Ltd | Health & social care | 2020 |
| Sempill Consulting Services Limited | Professional & scientific | 2024 |
| Senango Property Ltd | Real estate | 2020 |
| Senator Energy Services Limited | Administrative & support | 2002 |
| Sensory Needs Ltd | Wholesale & retail | 2018 |
| Sensory Wholesale Ltd | Wholesale & retail | 2019 |
| SEO & Web Ltd | Information & communication | 2016 |
| Sequeira Holdings Ltd | Financial services | 2025 |
| Sequeira Properties Ltd | Real estate | 2024 |
| Serenitas Ventures Ltd | Other services | 2026 |
| Serenity Psychological Therapies Ltd | Health & social care | 2023 |
| Serensia UK Ltd | Manufacturing | 2026 |
| SEV Electrical Limited | Construction | 2014 |
| Seven Four Seven SIX Limited | Arts & recreation | 2019 |
| Seventy SIX Salon Limited | Other services | 2021 |
| Sewell's Haulage Limited | Transport & logistics | 2015 |
| Sewing Universe Ltd | Wholesale & retail | 2020 |
| SG Lighting Ltd | Wholesale & retail | 2013 |
| SG6 Contracts Limited | Construction | 2020 |
| SGB Accounting Limited | Professional & scientific | 2021 |
| SGS General Services Limited | Transport & logistics | 2014 |
| Shabeeth UK Ltd | Wholesale & retail | 2024 |
| Shakery FM Limited | Administrative & support | 2025 |
| Shakery Group Ltd | Construction | 2022 |
| Shakery Holdings Limited | Financial services | 2025 |
| Shand Building Limited | Real estate | 2020 |
| Shand Solutions Ltd | Information & communication | 2023 |
| Sharmila Limited | Hospitality | 2001 |
| Sharp Installation Services Ltd | Construction | 2023 |
| Sharpstone Skinner Limited | Professional & scientific | 2007 |
| Shaw & Gambell Ltd | Real estate | 2006 |
| Shawford Mercurial Consulting Ltd | Professional & scientific | 2023 |
| Shecanna Ltd | Extraterritorial | 2019 |
| Shielding Solutions Limited | Manufacturing | 2005 |
| Shollyvat UK Limited | Wholesale & retail | 2025 |
| Show Diligence Productions Ltd | Administrative & support | 2009 |
| Showstoppr Ltd | Administrative & support | 2023 |
| Showstyle Limited | Administrative & support | 2016 |
| Shredder and Hygiene Services Limited | Manufacturing | 2006 |
| Shurety Coaching Ltd | Professional & scientific | 2006 |
| Sibeyond Ltd | Professional & scientific | 2024 |
| Sifam Tinsley Instrumentation Limited | Manufacturing | 2013 |
| Signalmanav Limited | Other services | 2018 |
| Signs 'N' Such Ltd | Manufacturing | 2021 |
| Signs Stitch & Print Ltd | Manufacturing | 2026 |
| Silent Lifeline Ltd | Health & social care | 2026 |
| Silkback Limited | Information & communication | 2003 |
| Sillet Graphics Limited | Professional & scientific | 2026 |
| Silver Bowl 123 Ltd | Hospitality | 2026 |
| Silver Bowl 688 Limited | Hospitality | 2024 |
| Silverend Food & Wine Limited | Wholesale & retail | 2017 |
| Silverleaf Consulting Ltd | Administrative & support | 2006 |
| Silverman Statue Ltd | Information & communication | 2024 |
| SIM Galvin Ltd | Administrative & support | 2025 |
| Simat (Essex) Limited | Information & communication | 2006 |
| Simbz Consulting Limited | Construction | 2026 |
| Simfinity Systems Ltd | Wholesale & retail | 2025 |
| Simon Wilson UK Sales Textiles & Haberdashery Ltd | Wholesale & retail | 2023 |
| Simply Wellness Ltd | Health & social care | 2024 |
| Simplyviable Holdings Limited | Financial services | 2024 |
| Simplyviable Solutions Limited | Professional & scientific | 2024 |
| Singula Limited | Information & communication | 2003 |
| Sinister Attire Ltd | Wholesale & retail | 2025 |
| Sinriam Ltd | Health & social care | 2022 |
| SIP Fresh Pressed Health Ltd | Wholesale & retail | 2025 |
| Siran Marquees Limited | Professional & scientific | 2005 |
| Sirrah Limited | Construction | 2023 |
| Sislet Solutions Limited | Information & communication | 2018 |