| Shree Samarth Properties Limited | Real estate | 2022 |
| Shreedeva Limited | Real estate | 2019 |
| Side GAS Services Ltd | Construction | 2025 |
| Signal Security Services Limited | Administrative & support | 2017 |
| Silver Bullet Music Limited | Arts & recreation | 2025 |
| Silver Comb Limited | Other services | 2020 |
| Simbara Ltd | Administrative & support | 2012 |
| Simon Hegele Logistics and Service Limited | Transport & logistics | 2004 |
| Simon Payne Management Ltd | Arts & recreation | 2015 |
| Simon SKI Tech Limited | Wholesale & retail | 2026 |
| Simone DE Haan Events Ltd | Administrative & support | 2021 |
| Simonski Limited | Other services | 2026 |
| Simple Kaizen Limited | Information & communication | 2020 |
| Simplexity Analysis Limited | Professional & scientific | 2014 |
| Simply Better Sheds Ltd | Construction | 2025 |
| Simply Serious Stories Limited | Arts & recreation | 2018 |
| SING2KARAOKE Limited | Wholesale & retail | 2024 |
| Singsational Limited | Arts & recreation | 2017 |
| Singular Machines Limited | Professional & scientific | 2024 |
| Sintona Ltd | Information & communication | 2023 |
| Sirius Farm Limited | Information & communication | 2021 |
| SIT UK Ltd | Wholesale & retail | 1958 |
| SK Cleaning Services Ltd | Administrative & support | 2025 |
| SKW Electrical Ltd | Construction | 2018 |
| Skye Barbour Ltd | Information & communication | 2018 |
| Skyrocket Services Ltd | Professional & scientific | 2024 |
| Skyward Commerce Group Ltd | Wholesale & retail | 2025 |
| SL Defval Ltd | Real estate | 2022 |
| SL Refi Ltd | Administrative & support | 2022 |
| SL2 Industries Ltd | Professional & scientific | 2024 |
| Slade Legal Ltd | Extraterritorial | 2024 |
| Sleeks Assets Limited | Real estate | 2019 |
| Sleepless Music Limited | Arts & recreation | 2019 |
| Sleepless Music Publishing Limited | Information & communication | 2022 |
| Sleepless Publishing Limited | Information & communication | 2022 |
| SLF Touring LLP | | 2016 |
| Sloper Electrical Services Limited | Construction | 2011 |
| Small Innovations Ltd | Information & communication | 2020 |
| Smart Garden Products Ltd | Wholesale & retail | 2002 |
| Smart Solar Ltd. | Wholesale & retail | 2013 |
| Smart Villages Research Group Ltd | Professional & scientific | 2017 |
| Smart-Settle-Go Ltd | Administrative & support | 2025 |
| Smarts Fish Bar Abingdon Ltd | Hospitality | 2025 |
| Smeg (UK) Limited | Wholesale & retail | 1989 |
| Smile Therapy by Ellie Limited | Health & social care | 2024 |
| Smith Robotics Ltd | Manufacturing | 2022 |
| SMS Food Group Limited | Agriculture & fishing | 2023 |
| Smyk Contractors Ltd | Administrative & support | 2017 |
| Snow Leopard Trust (UK) Limited | Education | 2006 |
| SNS at Rugby Ltd | Hospitality | 2025 |
| SNS D&G Rugby Ltd | Hospitality | 2022 |
| SNS FT Rugby Ltd | Hospitality | 2025 |
| SNS Kaspas Rugby Ltd. | Hospitality | 2014 |
| SNS Reading Ltd | Hospitality | 2025 |
| SNS Restaurants Ltd | Hospitality | 2016 |
| Snuggsys Gym Ltd | Arts & recreation | 2023 |
| Socimy Digital Ltd | Information & communication | 2023 |
| Soft Cheese Ltd | Hospitality | 2025 |
| Softspend Limited | Information & communication | 2025 |
| Sogrow Digital Ltd | Wholesale & retail | 2026 |
| Sola Virtus Solutions Ltd | Construction | 2026 |
| Solar Access Afrika & Telecommunications UK Ltd | Wholesale & retail | 2017 |
| Solar Village SDG CIC | Manufacturing | 2024 |
| Solarpanelbrian Ltd | Manufacturing | 2024 |
| Soll (Vale) | Arts & recreation | 2004 |
| Solutions in Energy Limited | Extraterritorial | 2015 |
| Solutions in Supported Living Limited | Real estate | 2020 |
| Solvein Holdings Limited | Agriculture & fishing | 2021 |
| Something Safe Limited | Other services | 2024 |
| Somewhere Good Ltd | Wholesale & retail | 2023 |
| Somit Solutions Limited | Professional & scientific | 2015 |
| Somnus Oxford Limited | Health & social care | 2015 |
| Sononaut Ltd | Arts & recreation | 2021 |
| Sons of Auto Ltd | Financial services | 2025 |
| Sophia Gomm Interiors Limited | Professional & scientific | 2025 |
| Sophos Limited | Information & communication | 1987 |
| Sophos Technology Limited | Information & communication | 2026 |
| Sophos Treasury Limited | Professional & scientific | 2015 |
| Sorbus Garden Care Limited | Administrative & support | 2016 |
| Sorrell, Williamson, Sorrell Limited | Information & communication | 2024 |
| Sotillo Consultants Limited | Professional & scientific | 2018 |
| Soul Paws Ltd | Wholesale & retail | 2025 |
| Sound Community Ltd | Arts & recreation | 2021 |
| South Avenue Management Ltd | Real estate | 2015 |
| South Oxfordshire Property Services Ltd | Construction | 2024 |
| Southern Ferries Travel Limited | Administrative & support | 2006 |
| Southern Hire Limited | Administrative & support | 2017 |
| Southernstream Limited | Wholesale & retail | 2026 |
| Soutmoor Barber Limited | Other services | 2025 |
| Space Cryomagnetics Limited | Manufacturing | 2000 |
| Spad Touring Limited | Arts & recreation | 2020 |
| Spartans Elite ABC CIC | Education | 2025 |
| Spartans Elite Boxing Ltd | Arts & recreation | 2023 |
| Specialist Manufacturing Solutions Ltd | Manufacturing | 2026 |
| Specialist Welding and Fabrication Ltd | Manufacturing | 2017 |
| Specklewood Ltd | Professional & scientific | 2017 |
| Spectre Capital Group Ltd | Wholesale & retail | 2024 |
| Speed DOT Limited | Administrative & support | 2024 |
| Speediance Life Technology(Uk) Limited | Wholesale & retail | 2025 |
| Spence Solutions Limited | Financial services | 2024 |