| Soysa Holdings 2025 Ltd | Transport & logistics | 2025 |
| Spacecraft Consulting Ltd | Professional & scientific | 2015 |
| Sparks Pilates Ltd | Arts & recreation | 2025 |
| Sparky Media Ltd | Information & communication | 2022 |
| Spearhead Training Group Limited | Education | 1981 |
| Specialegt Ltd | Administrative & support | 2022 |
| Spectra Productions LLP | | 2025 |
| Spectrum Sports Group Ltd | Education | 2019 |
| Spectrum Way Ltd | Construction | 2018 |
| Speech Limited | Information & communication | 2020 |
| Speed Steam Clean Ltd | Administrative & support | 2016 |
| Speediefingers Ltd | Professional & scientific | 2010 |
| Spencer Education Limited | Education | 2019 |
| SPEX2GO Ltd | Wholesale & retail | 2025 |
| Speyside Consulting Ltd | Professional & scientific | 2023 |
| Spicy Kebabish Ltd | Hospitality | 2017 |
| Spirac Limited | Water & waste | 1993 |
| Spirac Screenco Ltd | Water & waste | 2017 |
| Splendoor Properties Limited | Real estate | 2023 |
| Sport Entertainment & Partners Limited | Households | 2016 |
| Sporting & Historic Car Engineers Limited | Administrative & support | 2003 |
| Sports Advisory Service Limited | Arts & recreation | 2020 |
| Sports Legal Limited | Extraterritorial | 2018 |
| Spotless Professional Valeting Services Limited | Administrative & support | 2010 |
| Spotless Valeting Limited | Administrative & support | 2012 |
| Spratt Endicott Limited | Professional & scientific | 2012 |
| Spring Grounds Farm (2024) Limited | Agriculture & fishing | 2024 |
| Spring Grounds Farm LLP | | 2020 |
| SPS Innovations Limited | Health & social care | 2016 |
| Spsk Musketeer Limited | Hospitality | 2018 |
| SQ Meetings & Incentive Travel Limited | Administrative & support | 2006 |
| SQ303 Ltd | Transport & logistics | 2022 |
| Squad SIX Limited | Professional & scientific | 2021 |
| Squires Heating Services Limited | Construction | 2009 |
| SR Refinishing Ltd | Wholesale & retail | 2018 |
| SRD Home Maintenance Limited | Administrative & support | 2004 |
| SRS Rail UK. Ltd | Other services | 2014 |
| SS Complete Property (UK) Ltd | Households | 2025 |
| SSR Construction Limited | Construction | 2026 |
| ST. Mawes Limited | Administrative & support | 2017 |
| Stable Architecture Limited | Professional & scientific | 2005 |
| Stackers Training Limited | Professional & scientific | 2006 |
| Staffed Group Limited | Administrative & support | 2022 |
| Staffed Limited | Administrative & support | 2021 |
| Stalis Limited | Information & communication | 1991 |
| Stamp Homes Ltd | Real estate | 2020 |
| Stanbra Powell Group Limited | Real estate | 2023 |
| Stanbra Powell Ltd | Real estate | 2013 |
| Stanlet Property Ltd | Real estate | 2026 |
| Stanley-Grey Projects Ltd | Construction | 2017 |
| Starfish (Bicester) Limited | Real estate | 2015 |
| Starlight Logistics Limited | Transport & logistics | 2023 |
| Stars AJ Limited | Real estate | 2022 |
| Starshine Hospitality UK Ltd | Hospitality | 2026 |
| Start Making Limited | Information & communication | 2025 |
| Stat Consulting Ltd | Professional & scientific | 2010 |
| Statera Academy Ltd | Education | 2024 |
| Staticcreation Ltd | Information & communication | 2024 |
| Stay Comply Ltd | Hospitality | 2025 |
| Stay Human Reflexology Ltd | Education | 2023 |
| Steadivision Limited | Information & communication | 2014 |
| Steak Away Oxfordshire Ltd | Hospitality | 2024 |
| Stedman Corporate Clothing Limited | Manufacturing | 2010 |
| Steelwheeldeliveries Ltd | Transport & logistics | 2026 |
| Steeple Property Ltd | Construction | 2017 |
| Stefan Global SRL Ltd | Transport & logistics | 2024 |
| Stefanms Ltd | Transport & logistics | 2023 |
| Stellara Ltd | Wholesale & retail | 2026 |
| Step Inn Ltd | Real estate | 2020 |
| Step-Up Electrical Limited | Construction | 2017 |
| Stepbrick Ltd | Information & communication | 2025 |
| Stephanie Dakin Frcvs Equine Acupuncture Ltd | Professional & scientific | 2026 |
| Stephen Murray FD Services Ltd | Professional & scientific | 2019 |
| Stepolo Limited | Information & communication | 2016 |
| Steptoe & Daughter Limited | Wholesale & retail | 2003 |
| Stevenage Taxis Ltd | Transport & logistics | 2022 |
| Stevenage UK Ltd | Transport & logistics | 2018 |
| Stevens and Shipperley Limited | Wholesale & retail | 1959 |
| Stevepam Ltd | Financial services | 2022 |
| Stingray Security Ltd | Information & communication | 2019 |
| Stolford (the Chequers) Limited | Real estate | 2023 |
| Stoltek Consulting Ltd | Information & communication | 2015 |
| Stone Cold Classics Ltd | Wholesale & retail | 2015 |
| Stone Harbour Investment Ltd | Real estate | 2024 |
| Stone Harbour Ltd | Real estate | 2020 |
| Stonebridge Properties Limited | Real estate | 1986 |
| Stonecroft Associates Limited | Professional & scientific | 2000 |
| Stonelily Limited | Other services | 2012 |
| Store Your Will Ltd | Professional & scientific | 2026 |
| Stormgull Ltd | Professional & scientific | 2022 |
| Strangelove Films Limited | Information & communication | 2008 |
| Strategic Health Limited | Health & social care | 1994 |
| Strategic Ratings Ltd | Financial services | 2018 |
| Strategix Advisory Ltd | Professional & scientific | 2025 |
| Strategy IT Limited | Information & communication | 2011 |
| Strategy Wills Ltd | Other services | 2025 |
| Stratford Heating Services Ltd | Construction | 2021 |
| Stratton Thorpe Mortgage Solutions Ltd | Financial services | 2019 |
| Strawberry Bricks Ltd | Real estate | 2025 |
| Strella HR Consultancy Ltd | Administrative & support | 2026 |