| ST. Vincent's Charitable Trust | Health & social care | 1992 |
| ST. Vincents Nursery Limited | Education | 1996 |
| Stackedstore Ltd | Wholesale & retail | 2025 |
| Stadium Event Company (UK) Ltd | Administrative & support | 2004 |
| Stage Crazy Theatre School Limited | Education | 2007 |
| Stak Consulting Limited | Professional & scientific | 2014 |
| Stak Holding Limited | Manufacturing | 2015 |
| Stamford Bridge Investments Limited | Real estate | 2017 |
| Standard & Truworth Build & Decor UK PVT Ltd | Construction | 2024 |
| Standard & Truworth Developments UK Limited | Construction | 2018 |
| Standard and Truworth Estate Agents UK PVT Ltd | Real estate | 2024 |
| Standtall Limited | Administrative & support | 2008 |
| Stanley Park Properties Limited | Real estate | 2011 |
| Stanlo Limited | Financial services | 2018 |
| Stanlo Property Investments Limited | Real estate | 2022 |
| Stanton Consulting UK Ltd | Professional & scientific | 2008 |
| Staple Inn Properties Limited | Real estate | 1998 |
| Staple Wine Limited | Wholesale & retail | 2014 |
| Star Consultancy UK Limited | Professional & scientific | 2004 |
| Star Corporation Limited | Professional & scientific | 2019 |
| Stara Inc Ltd | Information & communication | 2023 |
| Starcare Homes Limited | Real estate | 2000 |
| Starme Ltd | Wholesale & retail | 2024 |
| Startnova Ltd | Education | 2020 |
| Startup Partner Ltd | Administrative & support | 2024 |
| Starview Residential Ltd | Administrative & support | 2017 |
| Starview Homes Limited | Real estate | 2007 |
| State of Saurashtra Ltd | Hospitality | 2023 |
| Stay on Ltd | Real estate | 2021 |
| Steamond Travel (Maida Vale) Limited | Administrative & support | 1994 |
| Stefan Budeanu Ltd | Construction | 2024 |
| Stellar Mind Tutors Limited | Education | 2024 |
| Stemsmart Tutors Limited | Education | 2025 |
| Stenson Consultancy Ltd | Health & social care | 2014 |
| Stenson Estates Ltd | Real estate | 2024 |
| Step by Step Management Ltd | Real estate | 2017 |
| Step Marketing Ltd | Information & communication | 2011 |
| Step One Recovery (UK) Limited | Health & social care | 2018 |
| Stephanie Rose Ltd | Information & communication | 2013 |
| Stephen Anthony Construction Ltd | Construction | 2026 |
| Stephen Anthony Developments Ltd | Real estate | 2017 |
| Sterling Professionals UK Ltd | Professional & scientific | 2019 |
| Sterling Properties London Limited | Real estate | 2015 |
| Stern Investments Limited | Professional & scientific | 2009 |
| Steve Finn Rights Limited | Arts & recreation | 2012 |
| Steve Walker (Fencing) Limited | Construction | 2009 |
| Steveclean Limited | Administrative & support | 2003 |
| Steven Shelley Associates Limited | Real estate | 2002 |
| Stickland & Co. Limited | Wholesale & retail | 1984 |
| Stickland Holdings Limited | Financial services | 2025 |
| Stilt Building Contractors Limited | Construction | 2021 |
| Stimpsons Scaffolding Ltd | Construction | 2024 |
| Stitches Hatch END Dresses Ltd | Administrative & support | 2018 |
| Stitches Hatch END Ltd | Administrative & support | 2017 |
| Stodanik Ltd | Construction | 2014 |
| Stoian Construction Ltd | Construction | 2022 |
| Stone Family Capital Limited | Real estate | 2025 |
| Stoneartuk Ltd | Administrative & support | 2018 |
| Stonecot Service Station LLP | | 2009 |
| Stonegrove Court RTM Company Limited | Households | 2024 |
| Stoneshield UK Holding Limited | Financial services | 2026 |
| Storage Services on Site Ltd | Transport & logistics | 2021 |
| Storm Partners Services UK Ltd | Other services | 2023 |
| Strange Creative Ltd | Professional & scientific | 2020 |
| Stratiqua Consulting Ltd | Professional & scientific | 2026 |
| Strong Oak Productions Limited | Information & communication | 2014 |
| Structural Engineering Design Centre Limited | Administrative & support | 2010 |
| Structureit Holdings Limited | Financial services | 2022 |
| Structureit Investments Ltd | Financial services | 2023 |
| Structureit Limited | Administrative & support | 2005 |
| STS Naturacares UK Ltd | Hospitality | 2022 |
| Studio C Limited | Information & communication | 2019 |
| Studio NO.8 Ltd | Wholesale & retail | 2026 |
| Studio Woodgate Limited | Professional & scientific | 2012 |
| Studioaida Ltd | Professional & scientific | 2014 |
| Stunt Power Films Limited | Arts & recreation | 2008 |
| Stupendous Productions Limited | Information & communication | 2025 |
| Styllo Limited | Financial services | 2008 |
| Suave Laundry Ltd | Other services | 2024 |
| SUB MAP Ltd | Hospitality | 2023 |
| Subham Consulting Limited | Information & communication | 2014 |
| Subnet 1 Business Ltd | Professional & scientific | 2016 |
| Subnet 1 IT Limited | Professional & scientific | 2013 |
| Subra Properties Ltd | Real estate | 2021 |
| Subshop Limited | Hospitality | 2013 |
| Substnz Limited | Professional & scientific | 2025 |
| Subway Reading Limited | Hospitality | 2001 |
| Succulent Theatre Ltd | Arts & recreation | 2023 |
| Sucellus Glas Design Ltd | Professional & scientific | 2023 |
| Sudbury Crescent Ltd | Real estate | 2026 |
| Sudbury Torch Ltd | Other services | 2022 |
| Sudel Ltd | Wholesale & retail | 2017 |
| SUE Cohen Limited | Professional & scientific | 2009 |
| Sugar Ends Limited | Information & communication | 2019 |
| Suhins Holdings Limited | Professional & scientific | 2025 |
| Suitable for Vegetarians Limited | Information & communication | 2012 |
| Sukanya Holdings Limited | Financial services | 2017 |
| Sulis Minerva Anaesthesia Limited | Administrative & support | 2019 |
| Sultan Business Management Limited | Professional & scientific | 2002 |
| Sultan Trader UK Ltd | Wholesale & retail | 2021 |