| Scenic Getaway Ltd | Extraterritorial | 2023 |
| Scent Borough Ltd | Wholesale & retail | 2025 |
| Scented Sensations Ltd | Manufacturing | 2018 |
| Scholarshub Ltd | Wholesale & retail | 2024 |
| School Close Road Association Limited | Other services | 2008 |
| School of London Limited | Education | 2025 |
| School of Presence Ltd | Education | 2025 |
| School Uniform 4U Ltd | Wholesale & retail | 2021 |
| School Uniform Direct (Essex) Ltd | Wholesale & retail | 2016 |
| Schooltopup Limited | Education | 2016 |
| SCI AID Ltd | Administrative & support | 2025 |
| Scissor Lounge Limited | Other services | 2021 |
| SCL Natureals Ltd | Wholesale & retail | 2010 |
| SCM Global Ltd | Administrative & support | 2017 |
| Scoala Mugurasi Romani Ltd | Education | 2024 |
| Scoot Courier Limited | Hospitality | 2017 |
| Scope Fire Systems Ltd | Construction | 2016 |
| Scopesys Ltd | Information & communication | 2025 |
| Scopuli Ltd | Information & communication | 2023 |
| Scorpion Skip Hire Limited | Water & waste | 2018 |
| Scorpius Interiors Ltd | Construction | 2024 |
| Scotline Limited | Transport & logistics | 1983 |
| Scotline Terminal (Medway) Limited | Transport & logistics | 1988 |
| Scotline Terminal (Transit) Limited | Transport & logistics | 1958 |
| Scrapco (Red Lodge) Limited | Wholesale & retail | 2021 |
| Scrapco Metal Recycling Limited | Wholesale & retail | 2010 |
| Screwkart Ltd | Wholesale & retail | 2025 |
| Sculpt Vitae Aesthetics Ltd | Other services | 2025 |
| Sculptural Face Lifting Ltd | Other services | 2022 |
| SD Dimitrov Transport Ltd | Transport & logistics | 2024 |
| SD Recruitment Ltd | Professional & scientific | 2020 |
| SD Supply Ltd | Wholesale & retail | 2010 |
| SD Waste Ltd | Water & waste | 2019 |
| Sd&C Healthcare Ltd | Health & social care | 2016 |
| SDA Estates Ltd | Construction | 2021 |
| SDA Fashion Ltd | Wholesale & retail | 2023 |
| SDA Hire and Travels Ltd | Administrative & support | 2026 |
| Sdh&M Ltd | Professional & scientific | 2024 |
| SDJ Building Supplies Ltd | Wholesale & retail | 2025 |
| SDJ Construction Ltd | Construction | 2020 |
| SDJ Investment Ltd | Real estate | 2024 |
| SDK Investments Limited | Real estate | 2015 |
| SDP Trading Ltd | Administrative & support | 2016 |
| SDT Contracts Limited | Construction | 2002 |
| Sea Breeze Residential Lets Ltd | Households | 2023 |
| Seagrace Limited | Real estate | 2012 |
| Seahaven C.H. Ltd | Health & social care | 2011 |
| Seales Road Haulage Limited | Transport & logistics | 1995 |
| Sean Land Limited | Households | 2020 |
| Seao Consulting Limited | Professional & scientific | 2025 |
| Searchmore Consultants Limited | Professional & scientific | 2016 |
| Searchmore Limited | Administrative & support | 2017 |
| Seas Medics Limited | Health & social care | 2023 |
| Seaview Career Ltd | Education | 2024 |
| SEB Property Ltd | Real estate | 2021 |
| SEB Steel Ltd | Manufacturing | 2016 |
| Sebyoto Ltd | Professional & scientific | 2025 |
| Seb’S Construction Ltd | Construction | 2021 |
| SEC Home Education Ltd | Education | 2024 |
| Second Sight Mental Health Assessments Limited | Health & social care | 2026 |
| Secret Aesthetics London Ltd | Administrative & support | 2023 |
| Secret Stock Limited | Wholesale & retail | 2021 |
| SECTORL3 Limited | Wholesale & retail | 2026 |
| Secure Access Security Ltd | Information & communication | 2019 |
| Secure Caring Hands Ltd. | Health & social care | 2020 |
| Secure IT Asset Disposal Ltd | Administrative & support | 2019 |
| Secure Nationwide Group Ltd | Administrative & support | 2022 |
| Secure Nest Holdings Limited | Real estate | 2023 |
| Secure Park NL Limited | Administrative & support | 2024 |
| Secure Place Ltd | Real estate | 2023 |
| Secured Network Ltd | Information & communication | 2012 |
| Securitaa UK Ltd | Transport & logistics | 2022 |
| Security Executive UK Ltd | Administrative & support | 2020 |
| Security WIZ Ltd | Administrative & support | 2021 |
| Security Works Limited | Information & communication | 2020 |
| Sedeelma Ltd | Wholesale & retail | 2026 |
| Sedulus Recruitment Limited | Professional & scientific | 2026 |
| SEE Partners Ltd | Energy | 2026 |
| SEE With ZEE Ltd | Health & social care | 2023 |
| Seeb London LLP | | 2017 |
| Seeds & Bloom Ltd | Agriculture & fishing | 2022 |
| Seega Accounting Limited | Professional & scientific | 2020 |
| Seega Limited | Professional & scientific | 2012 |
| Seekardo Ltd | Information & communication | 2025 |
| Seen by Smith Accessories Ltd | Manufacturing | 2024 |
| Seen by Smith Ltd | Manufacturing | 2026 |
| SEF23 Ltd | Wholesale & retail | 2023 |
| SEG Electrical Services Limited | Construction | 2025 |
| Sega Construction Ltd | Construction | 2024 |
| Segatastic Dance Company CIC | Health & social care | 2025 |
| SEK Program Ltd | Wholesale & retail | 2026 |
| Seka Construction Ltd | Construction | 2016 |
| Seka Renovations Ltd | Construction | 2026 |
| Selection Plus UK Limited | Wholesale & retail | 2025 |
| Selective Cars Ltd | Wholesale & retail | 2017 |
| Selectrical (Electrical Engineers & Contractors) Limited | Construction | 1990 |
| Selekt Logistics Limited | Transport & logistics | 2020 |
| Selenium Properties Ltd | Real estate | 2021 |
| Selesta Consultancy Ltd | Other services | 2023 |
| Selite Solutions Ltd | Construction | 2025 |