| Slindon Hotel Operations Limited | Hospitality | 2023 |
| SLN Solutions Limited | Information & communication | 2017 |
| Slow Century Records Limited | Wholesale & retail | 2025 |
| Sltf Holdings Limited | Real estate | 2023 |
| Slug and Lettuce Company Limited | Hospitality | 2007 |
| Slynk Digital Ltd | Information & communication | 2013 |
| SM Automotive Division Limited | Manufacturing | 2023 |
| SM Geotechnical Services Limited | Construction | 2021 |
| SM Housing Group Limited | Hospitality | 2025 |
| SM Lift Services Ltd | Manufacturing | 2016 |
| SM2 Studio Limited | Professional & scientific | 2008 |
| SMA Locum Ltd | Wholesale & retail | 2024 |
| SMA Trading Ltd | Administrative & support | 2012 |
| Small Batch Ltd | Information & communication | 2014 |
| Small Business Admin Solutions Limited | Administrative & support | 2016 |
| Small Crowd Developments Ltd | Real estate | 2020 |
| Small Heath Properties Management Ltd | Real estate | 2016 |
| Small Talk Sport Ltd | Arts & recreation | 2022 |
| Smalley Pastures Management Company Limited | Real estate | 2014 |
| Smart Bespoke Floors Ltd | Construction | 2025 |
| Smart Communications Group Ltd | Information & communication | 2015 |
| Smart Exams Ltd | Education | 2023 |
| Smart Factors Limited | Other services | 2012 |
| Smart Implants Limited | Health & social care | 2014 |
| Smart Living Homes Ltd | Real estate | 2020 |
| Smart Move Commercial Limited | Real estate | 2019 |
| Smart Move Investments Limited | Real estate | 2007 |
| Smart New Homes Limited | Real estate | 2020 |
| Smart Properties (England) Limited | Real estate | 2024 |
| Smart Properties Estate Agents Ltd | Real estate | 2014 |
| Smart Scholars Limited | Health & social care | 2025 |
| Smart Solar Sense Ltd | Energy | 2026 |
| Smart Strut Limited | Administrative & support | 2017 |
| Smart Technology Group Limited | Manufacturing | 2000 |
| Smart Technology Limited | Manufacturing | 2000 |
| Smartbite Consulting Ltd | Professional & scientific | 2025 |
| Smartbricks Properties & Estates Ltd | Hospitality | 2024 |
| Smartbricks Properties Ltd | Real estate | 2019 |
| Smarter Planet Finservice Limited | Professional & scientific | 2025 |
| Smarter Planet Holding Limited | Financial services | 2025 |
| Smarter Planet Solutions Limited | Information & communication | 2025 |
| Smartkey Rentals Ltd | Real estate | 2017 |
| Smartsi Ltd | Administrative & support | 2014 |
| Smartsi Services Limited | Construction | 2017 |
| SMB Innovations Limited | Hospitality | 2013 |
| SMH Electrical & Plastering Ltd | Construction | 2023 |
| Smhub Ltd | Hospitality | 2023 |
| Smile Concepts Limited | Health & social care | 2012 |
| Smiles and Skin Ltd | Health & social care | 2018 |
| Smiller Engineering Limited | Administrative & support | 2014 |
| Smitco Ltd | Information & communication | 2011 |
| Smith Hills Limited | Manufacturing | 2021 |
| Smith Property Solutions Limited | Extraterritorial | 2018 |
| Smiths Sheds & Fencing Limited | Wholesale & retail | 2015 |
| Smithtons Limited | Wholesale & retail | 2019 |
| SMJ Advisory Ltd | Professional & scientific | 2020 |
| Smjd Hospitality Ltd | Hospitality | 2023 |
| SMK Pharm Ltd | Health & social care | 2012 |
| SML Investments Limited | Financial services | 2026 |
| SML Medical Legal Services Ltd | Health & social care | 2012 |
| SML Real Estate Limited | Real estate | 2022 |
| Smoke Box BBQ Ltd | Wholesale & retail | 2019 |
| Smokey Joe's Cafe Ltd | Hospitality | 2014 |
| Smorgz Ltd | Information & communication | 2018 |
| SMS (Central) Ltd | Professional & scientific | 2016 |
| SMS One Ltd | Professional & scientific | 2000 |
| Smspropertyservices.Sa Ltd | Real estate | 2024 |
| SMT Ingenuity Limited | Education | 2021 |
| SMV Presses (U.K.) Limited | Other services | 1982 |
| SN GAS Solihull Limited | Construction | 2018 |
| SN Tech Support Ltd | Information & communication | 2021 |
| Snapable Limited | Professional & scientific | 2025 |
| Snapalogue Ltd | Information & communication | 2020 |
| SNB Fire Safety Limited | Professional & scientific | 2014 |
| Sneaker Spot Ltd | Other services | 2020 |
| Snkl Limited | Health & social care | 2022 |
| Snow IT Consultants Limited | Administrative & support | 2015 |
| Snowberry Gardens Property Management Limited | Households | 2003 |
| Snowdons Hairstylists (UK) Limited | Other services | 2001 |
| SNR Estates Ltd | Real estate | 2019 |
| Snug and Lettuce Ltd | Hospitality | 2022 |
| Snug and Still Limited | Wholesale & retail | 2025 |
| Snuggle the Panda Limited | Wholesale & retail | 2023 |
| Snuug Boilers Ltd | Administrative & support | 2025 |
| Snuug Co Ltd | Administrative & support | 2025 |
| Snuug Group Ltd | Financial services | 2025 |
| Snuug Heating Ltd | Administrative & support | 2025 |
| SO Asset Management Ltd | Professional & scientific | 2019 |
| SO Asset Management Two Ltd | Real estate | 2023 |
| SO Design & Development Ltd | Real estate | 2020 |
| SO Plastering Limited | Construction | 2008 |
| SO Pure Limited | Other services | 2000 |
| SO Simple Property Ltd | Real estate | 2023 |
| SO Students Ltd. | Real estate | 2017 |
| Soak WET Rooms and Bathrooms Ltd | Construction | 2025 |
| Soapbox Media Ltd | Information & communication | 2018 |
| Sobers 246 Electrical Limited | Other services | 2016 |
| Soby Cars Limited | Wholesale & retail | 2024 |
| Soby Trading Ltd | Wholesale & retail | 2024 |
| Socarts CIC | Arts & recreation | 2021 |