| SJ Construction & Sons Limited | Construction | 2010 |
| SJ Ventilation Ltd | Construction | 2021 |
| Sj-Prop Limited | Real estate | 2024 |
| Sj-Tpm Limited | Arts & recreation | 2020 |
| SJB Flooring Ltd | Construction | 2024 |
| SJB Tiling and Refurbishments Limited | Construction | 2015 |
| SJJ Investment Ltd | Real estate | 2024 |
| SJM Electrical Services (Southeast) Ltd | Construction | 2015 |
| SJM Renewables (Southeast) Ltd | Construction | 2022 |
| SJM York Limited | Real estate | 2021 |
| SJS Prop Ltd | Real estate | 2025 |
| Sjsk Limited | Health & social care | 2024 |
| SK Ace Global Ltd | Financial services | 2024 |
| SK Furniture Specialists Ltd | Manufacturing | 2023 |
| SK Juris Ltd | Real estate | 2025 |
| Skamat Resourse Limited | Professional & scientific | 2011 |
| Skap Services Ltd | Professional & scientific | 2008 |
| Skeete Productions Limited | Information & communication | 2025 |
| Skewer Street Food Ltd | Hospitality | 2023 |
| Skillbridge Academy Ltd | Professional & scientific | 2024 |
| Skin & Tonic Limited | Other services | 2010 |
| Skin Deep Aesthetics Ltd | Other services | 2023 |
| Skip Time Ltd | Water & waste | 2024 |
| SKM Projects Ltd | Real estate | 2023 |
| SKN Sona Ltd | Real estate | 2024 |
| Skonis Limited | Hospitality | 2009 |
| SKS Tech Ltd | Information & communication | 2026 |
| Sksr Limited | Real estate | 2025 |
| Sky Logic Ltd | Construction | 2012 |
| Sky Prism Ltd | Construction | 2021 |
| Sky Vintage Ltd | Real estate | 2024 |
| Sky-G Limited | Real estate | 2023 |
| Skyform Limited | Construction | 1988 |
| Skykare Ltd | Health & social care | 2025 |
| Skyklass Limited | Construction | 2009 |
| Skykom Homes Ltd | Real estate | 2023 |
| Skykom Limited | Information & communication | 2010 |
| Skylap Ltd | Wholesale & retail | 2020 |
| Skylap Properties Ltd | Real estate | 2021 |
| Skyler Contracting Limited | Construction | 2013 |
| Skyler Holdings Limited | Financial services | 2017 |
| Skylight Property Ltd | Real estate | 2024 |
| Skyluxe Cleaning Services Ltd | Administrative & support | 2024 |
| Skyluxe Roofing and Building Ltd | Construction | 2020 |
| Skynet ICT Ltd | Information & communication | 2019 |
| Skynett Technologies Limited | Information & communication | 2008 |
| SL Timber Trustee Limited | Financial services | 2022 |
| SLB Projects Ltd | Real estate | 2024 |
| Sleek Projects Ltd | Construction | 2022 |
| Sleepwright Ltd | Wholesale & retail | 2025 |
| Slim JIM Fitness Ltd | Arts & recreation | 2026 |
| SLK Investments Limited | Financial services | 2024 |
| SM & Son's Services Ltd | Construction | 2025 |
| SM Tech Ltd | Construction | 2015 |
| Small Chops Ltd | Hospitality | 2021 |
| Small Chops UK Corporation Ltd | Hospitality | 2018 |
| Small Places Partnership CIC | Health & social care | 2022 |
| Smarden Apartments (Ashford) Management Company Limited | Households | 2007 |
| Smart Accounting Solutions Limited | Professional & scientific | 2007 |
| Smart BIM UK Ltd | Information & communication | 2015 |
| Smart BMS Ltd | Construction | 2017 |
| Smart Construction and Services Ltd | Construction | 2015 |
| Smart Plus Electrical Ltd | Construction | 2013 |
| Smart Plus Heating Ltd | Construction | 2021 |
| Smart Property and Estates Limited | Real estate | 2022 |
| Smart Security Installs Ltd | Administrative & support | 2020 |
| Smart Services Group Limited | Professional & scientific | 2019 |
| Smart Telecoms Solutions Limited | Information & communication | 2017 |
| Smart Travel Chauffeur Services Limited | Transport & logistics | 2017 |
| Smart Vehicles for Sale Ltd | Wholesale & retail | 2022 |
| Smartcore Construction Ltd | Construction | 2025 |
| Smartlinks Care Services UK Ltd | Health & social care | 2020 |
| Smartview Windows and Doors Ltd | Construction | 2025 |
| Smashit Products Limited | Wholesale & retail | 2025 |
| SMB Reads Ltd | Administrative & support | 2017 |
| Smellycat Ltd | Wholesale & retail | 2018 |
| SMG Global Ltd | Information & communication | 2021 |
| Smiffy's Ltd. | Administrative & support | 1995 |
| Smifys Building and Carpentry Ltd | Construction | 2015 |
| Smifys Property Group Limited | Real estate | 2024 |
| Smile Avenue Ltd | Health & social care | 2017 |
| Smile Syndicate Ltd | Information & communication | 2025 |
| Smiley Kids Day Care Limited | Manufacturing | 2020 |
| Smiley Kidz Nursery Ltd | Education | 2021 |
| Smilyz Limited | Professional & scientific | 2013 |
| Smith & Byworth Limited | Construction | 2013 |
| Smith G Construction Ltd | Construction | 2018 |
| Smith Health Supplement Limited | Wholesale & retail | 2025 |
| Smln Limited | Real estate | 2026 |
| SMR Partners Ltd | Hospitality | 2024 |
| SMT Property & Financial Services Ltd | Financial services | 2023 |
| SN Crest Ltd | Construction | 2022 |
| SNA (Kent) Services Ltd | Administrative & support | 2021 |
| Snack Kitchen Limited | Wholesale & retail | 2021 |
| Snap Estates Ltd | Construction | 2024 |
| Snapnest Property Solutions Ltd | Real estate | 2025 |
| Snip of Clans Ltd | Wholesale & retail | 2025 |
| Sniris Investments Ltd | Real estate | 2026 |
| Sniris Limited | Manufacturing | 2021 |
| Snowblind Ltd | Administrative & support | 2011 |