| Stace Heating & Bathroom Renovations Limited | Construction | 2025 |
| Stache Cat Studios Ltd | Information & communication | 2025 |
| Stackdivers Ltd | Information & communication | 2025 |
| Stackpivot LAB Limited | Information & communication | 2021 |
| Stadium House Residents Association Limited | Households | 2006 |
| Stafa Mechanical Services Ltd | Construction | 2024 |
| Staff Security Services Limited | Administrative & support | 2007 |
| Stafford Management Limited | Households | 2013 |
| Stag House LLP | | 2015 |
| Stag House Resi LLP | | 2015 |
| Stagate AI Ltd | Information & communication | 2025 |
| Stage Zero Consulting Ltd | Professional & scientific | 2025 |
| Stagecoach House Management Company Limited | Households | 2006 |
| Stageomar Properties Limited | Real estate | 2011 |
| Stair Sainty Limited | Wholesale & retail | 2004 |
| Stakson Limited | Wholesale & retail | 2024 |
| Stalk Marketing Services Ltd | Information & communication | 2022 |
| Stalk Properties Ltd | Real estate | 2014 |
| Stallington Hall Management Company Limited | Households | 2013 |
| Stallions Steel Ltd | Wholesale & retail | 2025 |
| Stam Agro Ltd | Administrative & support | 2024 |
| Stamford Court (Macclesfield) Management Limited | Households | 1991 |
| Stammer Ltd | Wholesale & retail | 2026 |
| Stan 21 Ltd | Construction | 2019 |
| Stan Court Freehold Company Limited | Households | 2019 |
| Stand UP Fathers CIC | Public administration | 2023 |
| Stand With JA Community Interest Company | Other services | 2025 |
| Standard Healthcare Limited | Health & social care | 2023 |
| Standen House RTM Company Limited | Households | 2016 |
| Standing Start Trust | Health & social care | 2010 |
| Stanley Hill (Amersham) Management Company Limited | Households | 2014 |
| Stanley Raffington Limited | Wholesale & retail | 2023 |
| Stanley's Sports Academy Ltd | Education | 2021 |
| Stanley’S RUM Punch Limited | Manufacturing | 2019 |
| Stannis Ltd | Administrative & support | 2014 |
| Stanstead Close Management Company Limited | Households | 2007 |
| Stanstead Court Management Company Ltd | Households | 2007 |
| Stanverra Limited | Real estate | 2026 |
| Stanwell Fencing Ltd | Construction | 2023 |
| Stanworth Court Residents Company (Heston) Limited | Households | 1964 |
| Star 1 Care UK Limited | Health & social care | 2023 |
| Star and Garter Mansions (Management Company) Limited | Households | 2003 |
| Star Cash & Carry Limited | Extraterritorial | 2012 |
| Star Habitat UK Limited | Construction | 2018 |
| Star Hand Car Wash and Valeting Ltd | Administrative & support | 2018 |
| Star MAX Limited | Hospitality | 2021 |
| Star Noodles Ltd | Hospitality | 2025 |
| Star People Ltd | Real estate | 2022 |
| Star Systems Limited | Wholesale & retail | 2024 |
| Star Talent Group Ltd | Information & communication | 2009 |
| Starbridge Developments Limited | Construction | 2007 |
| Starcard UK Limited | Financial services | 2017 |
| Starflame Media Co., Ltd | Wholesale & retail | 2025 |
| Starfootball Ltd | Arts & recreation | 2018 |
| Stargazer Drug Stores Limited | Extraterritorial | 2013 |
| Stark Partners LLP | | 2010 |
| Starline Couriers Ltd | Transport & logistics | 2025 |
| Starr Installations Ltd | Construction | 2002 |
| Starr Radio UK Ltd | Information & communication | 2017 |
| Stars Constructions UK Ltd | Construction | 2020 |
| Startax Limited | Professional & scientific | 2002 |
| Starz Property Investments Ltd | Real estate | 2025 |
| Stateful Ltd | Information & communication | 2014 |
| Stateland Court Limited | Households | 2007 |
| Statewalk Limited | Households | 1986 |
| Station Meadows Apartments 1 Management Company Limited | Households | 2014 |
| Station Road (Chinnor) Residents Management Company Limited | Households | 2008 |
| Station Road (Hermitage) Limited | Households | 2005 |
| Station Road Dunstable (Phase 2) Management Company Limited | Households | 2013 |
| Status Employment Limited | Administrative & support | 1997 |
| Staysafe Healthcare Limited | Administrative & support | 2020 |
| STB Fine Foods Limited | Hospitality | 2019 |
| Steadham Ukeig | | 2012 |
| Steadings Rise Limited | Households | 1996 |
| Steadykey Limited | Real estate | 1995 |
| Steak Camden Ltd | Hospitality | 2023 |
| Steakout Meat Company Limited | Wholesale & retail | 2013 |
| Stealth Estates Ltd | Real estate | 2024 |
| Stealth Transport Limited | Transport & logistics | 2023 |
| Steam & Press Ltd | Other services | 2009 |
| Steam Shower Parts Limited | Wholesale & retail | 2017 |
| Steamer Street RTM Company Limited | Households | 2021 |
| Stean Group Limited | Professional & scientific | 2015 |
| Stebiz Limited | Real estate | 2000 |
| Stebiz Properties Ltd | Financial services | 2025 |
| Steel Fabrication Centre Ltd | Construction | 2017 |
| Steel Homes Ltd | Extraterritorial | 2024 |
| Steen Associates Ltd | Administrative & support | 2005 |
| Steeple View Residents Management Company Limited | Households | 2005 |
| Steerright Limited | Education | 2011 |
| Stefani 2000 Ltd | Transport & logistics | 2017 |
| Stefanoo Limited | Construction | 2014 |
| Stefford West Limited | Real estate | 2018 |
| Steling Limited | Construction | 2003 |
| Stellaris Property Ltd | Real estate | 2021 |
| Stema Group Ltd | Wholesale & retail | 2021 |
| Step | Education | 2009 |
| Step Care & Support | Health & social care | 2021 |
| Step in Future Ltd | Transport & logistics | 2024 |
| Step Industries Ltd | Wholesale & retail | 2019 |