| Saini Homes Limited | Real estate | 2021 |
| Saint Catherine's Care Ltd | Health & social care | 2020 |
| Salford Hill Limited | Hospitality | 2024 |
| Salon 122 Limited | Other services | 2015 |
| Salt BBA Ltd | Hospitality | 2016 |
| SAM Hitchcott Racing Limited | Arts & recreation | 2005 |
| SAM Partnership Ltd | Health & social care | 2018 |
| SAM Stronge Agency Ltd | Arts & recreation | 2022 |
| SAM Twiston-Davies Racing Ltd | Arts & recreation | 2015 |
| Same Ways Care Limited | Health & social care | 2018 |
| Sanctity Corp Ltd | Arts & recreation | 2022 |
| Sandford Sciences Limited | Professional & scientific | 2011 |
| Sanper Civils and Pipeline Engineering Ltd | Construction | 2024 |
| Sanper Construction Ltd | Construction | 2017 |
| Sanper Group Holdings Ltd | Financial services | 2023 |
| Sanper Investments Ltd | Construction | 2022 |
| Sanper Residential Ltd | Construction | 2024 |
| Sanper Technical Research & Development Ltd | Manufacturing | 2024 |
| Santec Europe Ltd. | Wholesale & retail | 1998 |
| Santino's Grill Lebanese Food Limited | Hospitality | 2024 |
| Santino's Grill Limited | Hospitality | 2024 |
| Santonna Limited | Real estate | 1963 |
| SAP Building Contractors Ltd | Construction | 2020 |
| SAP Ignite Limited | Information & communication | 2017 |
| Sarah Eberle Limited | Professional & scientific | 2020 |
| SAS 33 Services Ltd | Transport & logistics | 2023 |
| Sasha Ellese Ltd | Professional & scientific | 2020 |
| Saturn DS Construction Limited | Construction | 2014 |
| Saunor Wood Ltd | Manufacturing | 2019 |
| Saxons Heath 1961 Limited | Extraterritorial | 2014 |
| SB Direct Ltd | Transport & logistics | 2026 |
| SB Sport Management Ltd | Arts & recreation | 2024 |
| SBA Badminton Ltd | Arts & recreation | 2021 |
| SBA Events Ltd | Arts & recreation | 2024 |
| SBS Associates UK Ltd | Energy | 2021 |
| SBZ K Property Company Ltd | Real estate | 2022 |
| SC Clare Consulting Ltd | Professional & scientific | 2021 |
| SC Training Services Limited | Information & communication | 2006 |
| SC World Entertainment Ltd | Information & communication | 2024 |
| Scammell-Aec Limited | Manufacturing | 2021 |
| SCB (Oxford) Limited | Water & waste | 2010 |
| Sceptre Property Lets Ltd | Hospitality | 2024 |
| Science Practical Simulator Ltd | Information & communication | 2020 |
| Science Technology and Innovation for Development Ltd | Professional & scientific | 2013 |
| Scientific Magnetics Limited | Manufacturing | 2005 |
| Scientific Manufacturing Solution Ltd | Manufacturing | 2010 |
| SCM Property Services Limited | Construction | 2011 |
| Scratch Acoustic Ltd | Wholesale & retail | 2024 |
| SCS Oxon Ltd | Construction | 2023 |
| Scsc Consulting Ltd | Other services | 2018 |
| SD Audio Limited | Arts & recreation | 2024 |
| SD Cleaning Solutions Limited | Administrative & support | 2018 |
| SDC Resource Ltd. | Administrative & support | 2002 |
| SDI Catering Ltd | Manufacturing | 2016 |
| SDS Advisory Limited | Professional & scientific | 2024 |
| Seacub Limited | Manufacturing | 2006 |
| Sean Bowen Properties Ltd | Real estate | 2026 |
| Sean Bowen Racing Ltd | Arts & recreation | 2023 |
| Sean D Bowen Racing Limited | Arts & recreation | 2025 |
| Sean Levey Limited | Arts & recreation | 2014 |
| Second 2 None Vehicle Repairs Limited | Wholesale & retail | 2000 |
| Second Site Recruitment Ltd | Administrative & support | 2016 |
| Secureworks Europe Limited | Information & communication | 2015 |
| SEE More Seaside Limited | Real estate | 2022 |
| Seer Innovations Ltd | Information & communication | 2026 |
| Sekmen Commerce Ltd | Wholesale & retail | 2025 |
| Sellwood Road (Abingdon) Management Company Limited | Other services | 2010 |
| Semio Ltd | Professional & scientific | 2025 |
| Sena Bella Hair and Beauty Salon Ltd | Other services | 2025 |
| Sensational Auto Installations Ltd | Wholesale & retail | 2025 |
| Sense Biodetection Limited | Professional & scientific | 2013 |
| Sentido Ltd | Information & communication | 2023 |
| Sentinel Testing & Automation Engineering Ltd | Information & communication | 2011 |
| Sequent Limited | Administrative & support | 2017 |
| Serene Dwellings Ltd | Real estate | 2020 |
| Serenity Active Ltd | Arts & recreation | 2023 |
| Serpside Ltd | Information & communication | 2024 |
| Seva International Ltd | Professional & scientific | 2019 |
| Seven Commercial Properties Limited | Construction | 2021 |
| SGP Holdings (UK) Limited | Wholesale & retail | 2013 |
| SH Capital Investments Ltd | Real estate | 2021 |
| Shadowvu Ltd | Professional & scientific | 2023 |
| Shaldon Labour Services Ltd | Administrative & support | 2022 |
| Shaohua International Ltd | Wholesale & retail | 2019 |
| Sharman Roofing Ltd | Construction | 2024 |
| Sharps Auto Services Limited | Extraterritorial | 2000 |
| Sharps Autos Limited | Extraterritorial | 2000 |
| Shaun Branch Master Thatcher Ltd | Construction | 2015 |
| SHE Wears the Crown Records Ltd | Arts & recreation | 2026 |
| Shechinah Stays Ltd | Real estate | 2025 |
| Sheilas' Shutters Ltd | Wholesale & retail | 2017 |
| Shelvee Gain Group Limited | Administrative & support | 2024 |
| Sherborne Farms Limited | Agriculture & fishing | 2022 |
| Shifting Tides Productions Ltd | Information & communication | 2021 |
| Shining Digital Services Limited | Information & communication | 2025 |
| Shires Motofix Limited | Wholesale & retail | 2023 |
| Shoemark Piper Valet Service Ltd | Other services | 2023 |
| Shoemark Saddlery Ltd | Manufacturing | 2024 |
| Shomar Limited | Wholesale & retail | 2025 |
| Shoporiauk Ltd | Wholesale & retail | 2026 |