| SSR Build (Swansea) Limited | Real estate | 2026 |
| SSR Build Limited | Construction | 2022 |
| SSR Convenience Stores Limited | Wholesale & retail | 2017 |
| SSR Land (Croydon) Limited | Real estate | 2026 |
| SSR Land Limited | Construction | 2022 |
| SSR Projects Limited | Construction | 2023 |
| SSR Real Estate Limited | Real estate | 2022 |
| SSR Technologies (UK) Ltd | Information & communication | 2011 |
| SSR Townhill Limited | Real estate | 2025 |
| ST Claires Care Home Limited | Health & social care | 2023 |
| ST Freehold Limited | Real estate | 2021 |
| ST Georges Facilities Management Limited | Real estate | 2014 |
| ST Georges Group Holdings Ltd | Financial services | 2011 |
| ST Georges Healthcare Group Ltd | Financial services | 2026 |
| ST Georges Healthcare Services Ltd | Administrative & support | 2012 |
| ST Georges Supported Living Ltd | Health & social care | 2014 |
| ST Leonards Hill Limited | Real estate | 2019 |
| ST Lukes Projects Ltd | Real estate | 2020 |
| ST Mary's Arts Trust | Arts & recreation | 2011 |
| ST. Ambrose Green Management Company Limited | Households | 1993 |
| ST. M’S Thera Spa Limited | Health & social care | 2025 |
| Stable Services Ltd. | Professional & scientific | 2020 |
| Stadler UK Limited | Manufacturing | 2007 |
| Staffsign Limited | Professional & scientific | 2004 |
| Stag Brewery Ltd | Manufacturing | 2017 |
| Stag Building Solutions Limited | Construction | 2021 |
| Stag Developments South East Limited | Construction | 2023 |
| Stage One Research Stimulus Limited | Professional & scientific | 2013 |
| Stage One Storyboards Limited | Professional & scientific | 2015 |
| Stagegremlin Ltd | Information & communication | 2017 |
| Stagg & Sparrow Limited | Other services | 2017 |
| Staines Investments Ltd | Real estate | 2025 |
| Staines MOT Centre Limited | Wholesale & retail | 2006 |
| Staines Upon Thames Windows & Doors Limited | Construction | 2025 |
| Stakehaus Ltd. | Hospitality | 2015 |
| Stand OUT Multimedia Ltd | Information & communication | 2013 |
| Standen Developments (Kent) Limited | Construction | 2020 |
| Standout Holdings Ltd | Financial services | 2026 |
| Standout Properties Ltd | Real estate | 2026 |
| Standys Candy Ltd | Hospitality | 2023 |
| Stanford Bridge Consultancy Ltd | Professional & scientific | 2023 |
| Stanhope Kebab Ltd | Hospitality | 2024 |
| Stanley Road NO 38 Limited | Households | 2006 |
| Stanwell Autos Ltd | Wholesale & retail | 2022 |
| Stanwell Builder Limited | Construction | 2024 |
| Star Cabaret Ltd | Wholesale & retail | 2012 |
| Star Home Design & Build Ltd | Construction | 2026 |
| Stardust Studios Performing Arts Limited | Arts & recreation | 2023 |
| Starkings Scaffolding Ltd | Construction | 2023 |
| Starline Taxi Service Ltd | Transport & logistics | 2026 |
| Starlynx Ltd | Professional & scientific | 2022 |
| Staron Construction Ltd | Construction | 2019 |
| Starpim Limited | Administrative & support | 2005 |
| Starters Football Academy Ltd | Education | 2023 |
| Starwayz Consultancy Limited | Professional & scientific | 2021 |
| Starzine Limited | Wholesale & retail | 2014 |
| Stateless Productions Limited | Administrative & support | 2010 |
| Staying Busy Films Limited | Information & communication | 2025 |
| Staysure Roofing & Building Ltd | Construction | 2026 |
| Steadfast Logistics Ltd | Transport & logistics | 2017 |
| Stealth Rail Testing Ltd | Professional & scientific | 2015 |
| Steede Interiors Ltd | Construction | 2025 |
| Steelefen Ltd | Construction | 2020 |
| Steelson Plant Limited | Construction | 2018 |
| Steer Your Business Limited | Administrative & support | 2018 |
| Steeralign Ltd | Wholesale & retail | 2013 |
| Stef Speed Logistic Ltd | Wholesale & retail | 2021 |
| Steldam Services Limited | Information & communication | 2021 |
| Stellar Ensemble Limited | Information & communication | 2025 |
| Step OUT Journeys Ltd | Wholesale & retail | 2026 |
| Step-Out Outdoor Learning, Training and Therapy C.I.C. | Education | 2011 |
| Stepart Plastics Limited | Manufacturing | 2011 |
| Stephanie Smith Events Ltd | Administrative & support | 2021 |
| Stephen & Sons Property Limited | Real estate | 2021 |
| Stephen James Consulting Services Limited | Professional & scientific | 2024 |
| Stephen John Payne Ltd | Manufacturing | 2022 |
| Stephen O'Brien Plastering Ltd | Construction | 2024 |
| Stephensons Group Limited | Administrative & support | 2026 |
| Stereo App Limited | Information & communication | 2020 |
| Sterling Edge Group Ltd | Wholesale & retail | 2025 |
| Sterlings Growth Limited | Hospitality | 2026 |
| Steve Knell Rail Services Limited | Administrative & support | 2016 |
| Steve Pack Lime and Fertiliser Limited | Agriculture & fishing | 2018 |
| Steve Sidwell Limited | Administrative & support | 2008 |
| Stevens & Co. (SE) Limited | Real estate | 2004 |
| Stevens Civil Engineering Limited | Construction | 2016 |
| Stevenson Brothers Promotions Limited | Administrative & support | 2000 |
| Stevenson Brothers Very Fine Rocking Horses Limited | Extraterritorial | 2006 |
| Stevensons Properties Limited | Real estate | 2019 |
| Stevie’S Cozy Dive Ltd | Hospitality | 2026 |
| Stewart Financial Solutions Limited | Financial services | 2005 |
| Stewarts Lettings Limited | Real estate | 2024 |
| STF Europe Ltd | Wholesale & retail | 2024 |
| STF Publications Limited | Wholesale & retail | 1932 |
| Sticky Fingers Limited | Education | 2024 |
| Stilson Holdings Ltd | Construction | 2020 |
| Stirling Windows Limited | Construction | 2019 |
| Stitch & Stuff Limited | Other services | 2011 |
| Stitcha UK Limited | Information & communication | 2026 |
| Stmc Group Ltd | Education | 2019 |