| Suffolk Newmedica Limited | Health & social care | 2018 |
| Sulit Ventures Ltd | Wholesale & retail | 2026 |
| Summers Holiday Ltd | Hospitality | 2024 |
| Summit Construction (1975) Ltd | Construction | 2017 |
| Summit Prospecting Ltd | Professional & scientific | 2023 |
| Sun Blooming Ltd | Wholesale & retail | 2024 |
| Sundays Hill MOT Centre Limited | Wholesale & retail | 2013 |
| Sunderland Specsavers Hearcare Limited | Wholesale & retail | 2005 |
| Sunderland Specsavers Limited | Wholesale & retail | 1991 |
| Sunderland Visionplus Limited | Wholesale & retail | 1998 |
| Sunflower Design Limited | Professional & scientific | 2002 |
| Sunnydale Motor Company Limited | Wholesale & retail | 2017 |
| Sunnypath Solutions Ltd | Professional & scientific | 2025 |
| Sunvast International UK Limited | Construction | 2018 |
| Super Spars Limited | Manufacturing | 2003 |
| Superb Carpentry Ltd | Construction | 2023 |
| Supercar Switch Limited | Administrative & support | 2025 |
| Superclean Sludge Limited | Extraterritorial | 1980 |
| Superkidz Home Oasis Limited | Wholesale & retail | 2020 |
| Supermarket Savers Ltd | Information & communication | 2025 |
| Supply & Build Ltd | Construction | 2024 |
| Supply Electrical Ltd | Manufacturing | 2012 |
| Supplykee Limited | Information & communication | 2024 |
| Support Nest Recruitment Services Ltd | Administrative & support | 2025 |
| Support Nest Services Ltd | Health & social care | 2022 |
| Support on the Spot Limited | Information & communication | 2009 |
| Supreme SLS Limited | Professional & scientific | 2026 |
| Surbiton Specsavers Limited | Wholesale & retail | 2009 |
| Surbiton Visionplus Limited | Wholesale & retail | 2009 |
| Surefire Outdoor Ltd | Wholesale & retail | 2025 |
| Suresan Ltd | Administrative & support | 2020 |
| Surfire UK Ltd | Professional & scientific | 2025 |
| Surgecell Limited | Professional & scientific | 2025 |
| Suristy Ltd | Real estate | 2024 |
| Surrey 2 Domiciliary Specsavers Limited | Wholesale & retail | 2014 |
| Surrey Building & Renovation Limited | Construction | 2019 |
| Surrey Quays Specsavers Limited | Wholesale & retail | 2007 |
| Surrey Quays Visionplus Limited | Wholesale & retail | 2007 |
| Susan Maillard Physiotherapy Services Ltd | Health & social care | 2026 |
| Sussex Hats Ltd | Manufacturing | 2026 |
| Sussex Student Accommodation Ltd | Hospitality | 2025 |
| Sussextech Limited | Information & communication | 2015 |
| Sustainable Design Studio Ltd | Professional & scientific | 2024 |
| Sutton Coldfield Specsavers Hearcare Limited | Wholesale & retail | 2007 |
| Sutton Coldfield Specsavers Limited | Wholesale & retail | 1986 |
| Sutton Coldfield Visionplus Limited | Wholesale & retail | 1993 |
| Sutton Specsavers Hearcare Limited | Wholesale & retail | 2005 |
| Sutton-In-Ashfield Specsavers Hearcare Limited | Wholesale & retail | 2022 |
| Sutton-In-Ashfield Specsavers Limited | Wholesale & retail | 1995 |
| Sutton-In-Ashfield Visionplus Limited | Wholesale & retail | 1995 |
| SVN Consulting Ltd | Professional & scientific | 2025 |
| Swadlincote Specsavers Limited | Wholesale & retail | 2005 |
| Swadlincote Visionplus Limited | Wholesale & retail | 2005 |
| Swainylock Security Services Ltd | Administrative & support | 2023 |
| Swaledale Specsavers Limited | Wholesale & retail | 2008 |
| Swaledale Visionplus Limited | Wholesale & retail | 2008 |
| Swali & Batchelor Property Ventures Ltd | Construction | 2025 |
| Swan Quay Management Limited | Households | 1993 |
| Swan Systems Furniture Limited | Manufacturing | 2003 |
| Swan Wade Properties Limited | Real estate | 2020 |
| Swanley Specsavers Limited | Wholesale & retail | 2016 |
| Swann Financial Limited | Financial services | 2021 |
| Swannie Property Services Ltd | Real estate | 2011 |
| Swans Property Estates Limited | Real estate | 2024 |
| Swansea Specsavers Hearcare Limited | Wholesale & retail | 2018 |
| Swansea Specsavers Limited | Wholesale & retail | 1991 |
| Swansea Visionplus Limited | Wholesale & retail | 1993 |
| Sweepbox Cleaners Ltd | Administrative & support | 2021 |
| Sweet Candy Portchester Ltd | Wholesale & retail | 2024 |
| Sweet Management Ltd | Administrative & support | 2016 |
| Sweetiepost Ltd | Wholesale & retail | 2022 |
| Swift Arrow Logistics Limited | Transport & logistics | 2026 |
| Swift Boat Services Limited | Manufacturing | 2025 |
| Swift Training UK Ltd | Education | 2020 |
| Swim School Academy Fareham LLP | | 2026 |
| Swim School Academy Ltd | Arts & recreation | 2008 |
| Swindon Specsavers Hearcare Limited | Wholesale & retail | 2005 |
| Swindon Specsavers Limited | Wholesale & retail | 1986 |
| Swindon Visionplus Limited | Wholesale & retail | 1994 |
| Swinton Specsavers Hearcare Limited | Wholesale & retail | 2018 |
| Swiss Cottage Specsavers Limited | Wholesale & retail | 2011 |
| Switch Boxing Events Ltd | Arts & recreation | 2026 |
| Switch ME (Southern) Limited | Professional & scientific | 2024 |
| Switch My Service Limited | Information & communication | 2022 |
| SWR Architect Ltd | Professional & scientific | 2017 |
| Swurv Research Limited | Information & communication | 2024 |
| Swytch Ltd | Construction | 2021 |
| Sycamore Hifi Limited | Wholesale & retail | 2020 |
| Sydenham Healthcare Limited | Health & social care | 2012 |
| Sydenham Specsavers Limited | Wholesale & retail | 2018 |
| Sydney Fate Ltd | Arts & recreation | 2022 |
| SYG Consulting Ltd | Professional & scientific | 2025 |
| SYL Family Investments Limited | Financial services | 2024 |
| Symbility Solutions Limited | Information & communication | 2015 |
| Synack Limited | Information & communication | 2007 |
| Syncup Events Ltd | Information & communication | 2025 |
| Synergeyes UK Limited | Other services | 2018 |
| Synergy Testing Limited | Information & communication | 2009 |
| Synergy Wealth Planning Limited | Professional & scientific | 2017 |
| Syntirisi Limited | Construction | 2019 |