| Sanum Advisory Limited | Professional & scientific | 2019 |
| Sanvia Pharmaceuticals Limited | Agriculture & fishing | 2025 |
| SAP Estates Limited | Real estate | 2022 |
| Sapnet Software Services Limited | Information & communication | 2025 |
| Sapphire Estate Agents Limited | Real estate | 2004 |
| Saracen Developments Limited | Construction | 2018 |
| Sarah Woodward Coaching Ltd | Professional & scientific | 2013 |
| Sarayu IT Consultancy Services Ltd | Information & communication | 2018 |
| Sarim Consultancy Ltd | Professional & scientific | 2019 |
| Sartin Estates Limited | Real estate | 2014 |
| Sarva Shri Limited | Administrative & support | 2005 |
| SAS Construction Projects Ltd | Construction | 2025 |
| SAS Law Limited | Professional & scientific | 2012 |
| Sauce and Flour Ltd | Hospitality | 2020 |
| Sauce Creative Group Ltd | Professional & scientific | 2025 |
| Savagem Limited | Manufacturing | 2016 |
| Save the Sash Ltd | Construction | 2014 |
| Savethestreetpooches SRI Lanka | Other services | 2018 |
| Savian Properties Ltd | Construction | 2024 |
| Savile ROW Property Ltd | Financial services | 2014 |
| Sawtooth Creative Limited | Information & communication | 2013 |
| Saxum Technology Ltd | Information & communication | 2012 |
| Sayarah Ltd | Wholesale & retail | 2025 |
| SB & ML Property Management Limited | Households | 2021 |
| SBR Real Estate Ltd | Real estate | 2026 |
| Scaffolding Safety Security Services Limited | Public administration | 2026 |
| Scaleup Solutions Limited | Professional & scientific | 2018 |
| Scancem Energy and Recovery Limited | Financial services | 1998 |
| Scancem International Limited | Professional & scientific | 1991 |
| Scancem Recovery Limited | Financial services | 1998 |
| Scancem Supply Limited | Financial services | 1990 |
| Scandi-Chic UK Limited | Wholesale & retail | 2006 |
| Scate Services Limited | Professional & scientific | 2021 |
| Scenario Solutions Ltd. | Information & communication | 1999 |
| Scenarioai Limited | Information & communication | 2025 |
| Schedox Ltd | Information & communication | 2026 |
| School of Philanthropy Ltd | Extraterritorial | 2024 |
| Schumacher Ltd | Professional & scientific | 2018 |
| Sci-Search Limited | Administrative & support | 2025 |
| Science & Care Ltd | Wholesale & retail | 2012 |
| Scionovus Limited | Professional & scientific | 2024 |
| Scmgt Ltd | Professional & scientific | 2013 |
| Scorch & Sizzle Ltd | Manufacturing | 2025 |
| Scott SP Ltd | Extraterritorial | 2025 |
| Scottcam Holdings Limited | Financial services | 1989 |
| Scottish Borders Education Partnership (Holdings) Limited | Financial services | 2006 |
| Scottish Borders Education Partnership Limited | Financial services | 2006 |
| Scraptures Ltd | Wholesale & retail | 2026 |
| Scrollbar Limited | Information & communication | 2014 |
| Scrubs Car Wash Ltd | Other services | 2020 |
| Scrubs Storage Ltd | Real estate | 2024 |
| Scrumtech Ltd | Information & communication | 2018 |
| SCS Brickwork Ltd | Construction | 2004 |
| Scubacrew.Net Ltd | Arts & recreation | 2016 |
| SCZ Pharma Consulting Ltd | Health & social care | 2017 |
| SD Projects Ltd | Construction | 1999 |
| SDI Partners Ltd | Professional & scientific | 2022 |
| SDL (Newbury) Limited | Information & communication | 1996 |
| SDL Global Holdings Limited | Information & communication | 2000 |
| SDL Limited | Information & communication | 1992 |
| SDL Nominees Limited | Professional & scientific | 2011 |
| SDL Sheffield Limited | Professional & scientific | 1986 |
| SDL Tridion Limited | Information & communication | 1999 |
| Sdqa CIC | Other services | 2025 |
| Sea & Road Technicians Limited | Transport & logistics | 2008 |
| Sea of Stars Food Limited | Wholesale & retail | 2023 |
| Seagoe Concrete Products Limited | Professional & scientific | 1935 |
| Sean Harris Services Limited | Information & communication | 2016 |
| Search Allies Ltd | Administrative & support | 2021 |
| Seascape Island Management Limited | Wholesale & retail | 2012 |
| Seasonality Ltd | Wholesale & retail | 2020 |
| Sebastian Graus Limited | Information & communication | 2025 |
| Second City Properties Limited | Professional & scientific | 1891 |
| Second Front Systems Limited | Information & communication | 2023 |
| Second GEN Films Ltd | Construction | 2025 |
| Second Sun Ltd | Information & communication | 2020 |
| Secret Sales Director Limited | Information & communication | 2024 |
| Seed Pantry Ltd | Wholesale & retail | 2009 |
| Seeds Estates Limited | Real estate | 2024 |
| Seelee Consulting Ltd | Information & communication | 2018 |
| Seema Pankhania Ltd | Information & communication | 2022 |
| Sefton Capture Ltd | Information & communication | 2021 |
| Segrue Investments Ltd | Construction | 2020 |
| Segrue Rentals Limited | Real estate | 2026 |
| Sehall Carpentry Limited | Manufacturing | 2019 |
| Seher & Laiba Ltd | Health & social care | 2018 |
| Seiko U.K. Limited | Wholesale & retail | 1971 |
| Select Performance & Partners Ltd | Wholesale & retail | 2025 |
| Self-Insight Limited | Professional & scientific | 2005 |
| Selvan Medical Associates Ltd | Health & social care | 2009 |
| Semper-Smith Associates Limited | Professional & scientific | 2023 |
| Senco Energy Ltd | Financial services | 2011 |
| Senco Investment Holdings Ltd | Financial services | 2025 |
| Senco Property Holdings Ltd | Real estate | 2021 |
| Sensor Data Services Limited | Professional & scientific | 2003 |
| Sentinal Services Property Maintenance LLP | | 2024 |
| Seqirus Holdings UK Limited | Professional & scientific | 2015 |
| Seqirus Limited | Professional & scientific | 2015 |
| Seqirus UK Limited | Professional & scientific | 2015 |
| Sequensys Ltd | Professional & scientific | 2013 |