| Safe Tranz Systems Property Investment Limited | Wholesale & retail | 2021 |
| Safe Zone Dating Ltd | Information & communication | 2026 |
| Safe! Support for Young People Affected by Crime Limited | Other services | 2011 |
| Safebridge Services Ltd | Hospitality | 2025 |
| Safecypher Limited | Information & communication | 2022 |
| Safeduty Protective Group Limited | Administrative & support | 2024 |
| Safeguard AI Ltd | Information & communication | 2024 |
| Safeguard Walls Ltd | Construction | 2025 |
| Safeguarding Travel Ltd | Transport & logistics | 2026 |
| Safer Birth Limited | Information & communication | 2024 |
| Safetyknot Ltd | Professional & scientific | 2018 |
| Safetynet Care Limited | Administrative & support | 2019 |
| Safwan Kareem Ltd | Real estate | 2023 |
| Sagacity Research Ltd | Information & communication | 2014 |
| Sageascent Ltd | Information & communication | 2025 |
| SAH Enterprises Limited | Administrative & support | 2013 |
| Sahara Accountancy Solution Ltd | Professional & scientific | 2023 |
| Sahara Security Ltd | Administrative & support | 2016 |
| Sahars Holdings Ltd | Real estate | 2017 |
| Saibre Ltd | Information & communication | 2023 |
| Saint Enterprises Ltd | Wholesale & retail | 2021 |
| Saint Fiacre Limited | Agriculture & fishing | 2021 |
| SAL Construction & Maintenance Limited | Construction | 2021 |
| Sale & Sale Company Limited | Wholesale & retail | 2004 |
| Sales Development Leaders Limited | Professional & scientific | 2024 |
| Sales Drive Limited | Professional & scientific | 2012 |
| Salianz Limited | Professional & scientific | 2018 |
| Salisbury Sushi Ltd | Wholesale & retail | 2024 |
| Sallu Traders Ltd | Wholesale & retail | 2025 |
| Salma Chaudhury Medicolegal Ltd | Health & social care | 2024 |
| Salmon Ophthalmology Oxford Ltd | Health & social care | 2018 |
| Salsa DEL SOL Ltd | Hospitality | 2022 |
| Salt & Vinegar Oxford Ltd | Hospitality | 2022 |
| Salter Bros,Limited | Real estate | 1915 |
| Salter's Steamers Limited | Transport & logistics | 1945 |
| Salticore Limited | Information & communication | 2010 |
| Saltwater Communications Limited | Professional & scientific | 1997 |
| Salty Dog Whisky Limited | Wholesale & retail | 2025 |
| SAM & Sons Ltd | Wholesale & retail | 2020 |
| SAM Mackeith Ltd | Health & social care | 2018 |
| SAM Mart Oxford Limited | Wholesale & retail | 2025 |
| SAM Renovation Ltd | Extraterritorial | 2025 |
| Samatya Ltd | Health & social care | 2023 |
| Samir Thapa Ltd | Information & communication | 2026 |
| Sammyness Limited | Health & social care | 2023 |
| Samol Investments Limited | Real estate | 1959 |
| Sampleasset Limited | Households | 1997 |
| Sampson Bland Ltd. | Professional & scientific | 2015 |
| Samsa Services Ltd | Construction | 2025 |
| Samsara Therapeutics Ltd | Professional & scientific | 2019 |
| Samteck Care Solutions Limited | Health & social care | 2013 |
| Samuel James Engineering Limited | Manufacturing | 1993 |
| Samvia Ltd | Wholesale & retail | 2026 |
| Samwise Capital Ltd | Financial services | 2025 |
| SAN Physiotherapy Ltd | Health & social care | 2024 |
| Sanaa Center Consultancy Ltd | Professional & scientific | 2020 |
| Sanam Kebabish Ltd | Hospitality | 2015 |
| Sancar Family Development Ltd | Real estate | 2023 |
| Sancar Family Ltd | Real estate | 2023 |
| Sanco Kitchen Ltd | Hospitality | 2026 |
| Sandars Green Education Limited | Education | 2012 |
| Sandfield Consultancy Limited | Professional & scientific | 2019 |
| Sandpenguin Ltd | Information & communication | 2026 |
| Sandway Paving Limited | Construction | 2024 |
| Sandymount Therapeutics Ltd | Professional & scientific | 2021 |
| Sandys Holdings Ltd | Hospitality | 2018 |
| Sandy’S London Limited | Hospitality | 2018 |
| Sanghera Supermarket Limited | Wholesale & retail | 2005 |
| Sanj & Soph Ltd | Health & social care | 2020 |
| Sanmarzano Ltd | Hospitality | 2023 |
| Santa Rita Europe Limited | Manufacturing | 2003 |
| Sapientia Ltd | Information & communication | 2019 |
| Sapier Ltd | Professional & scientific | 2013 |
| Sara Beck Coaching Ltd | Professional & scientific | 2025 |
| Sara Riley London Ltd | Other services | 2018 |
| Saracen Cars Ltd | Administrative & support | 2025 |
| Sarah Ives Associates Limited | Professional & scientific | 2015 |
| Sarah Lawrence at Oxford | Education | 2006 |
| Sarah Muthoni Ltd | Administrative & support | 2019 |
| Saran Family Consultants Ltd | Professional & scientific | 2024 |
| Saranta Associates Limited | Administrative & support | 2019 |
| Saranta Ltd | Administrative & support | 2016 |
| Sararsha Private Limited | Real estate | 2024 |
| Sarjon Properties Ltd | Real estate | 2017 |
| Sarsabad Limited | Hospitality | 2020 |
| Sarwar IT Limited | Information & communication | 2017 |
| SAS Corporation Limited | Wholesale & retail | 2024 |
| Sasi's Thai Ltd | Hospitality | 2013 |
| Saukavi PVT Ltd | Wholesale & retail | 2026 |
| Saunaverse Events Ltd | Education | 2024 |
| Saunaverse Ltd | Health & social care | 2023 |
| Saunders Agriculture Ltd | Agriculture & fishing | 2025 |
| Saunt Limited | Real estate | 2005 |
| Saurabh Doshi Ltd | Information & communication | 2024 |
| Savaget Limited | Information & communication | 2020 |
| Save Energy World Ltd | Construction | 2015 |
| Savori Group Ltd | Information & communication | 2026 |
| Savvy Building Limited | Construction | 2023 |
| Savvy Construction Ltd | Construction | 2010 |
| Savvy Developments Ltd | Construction | 2015 |