| SSA Electrical Ltd | Construction | 2019 |
| Ssfcf 2017 Limited | Hospitality | 2020 |
| SSH Group Holding Company Limited | Financial services | 2018 |
| SSH Property Limited | Administrative & support | 2018 |
| Ssmt Group Ltd | Administrative & support | 2024 |
| SSW Coaching & Consultancy Ltd | Professional & scientific | 2025 |
| ST James(Partnership) Ltd | Real estate | 2024 |
| STABLE10 Ltd | Administrative & support | 2023 |
| Stack Digital Limited | Professional & scientific | 2019 |
| Stadium Consumer Products Limited | Wholesale & retail | 2001 |
| Stadium Container Storage Ltd | Other services | 2022 |
| Stadium Supreme Ltd | Hospitality | 2023 |
| Stagdale Developments Limited | Real estate | 2025 |
| Stainforth Engineering Ltd | Professional & scientific | 2024 |
| Stainsby Commercial Ltd | Real estate | 2022 |
| Stainsby Grange Pegasus CIC | Education | 2021 |
| Stainsby Produce Limited | Wholesale & retail | 2012 |
| Stainsby Property Developments Ltd | Real estate | 2021 |
| Stalight Ltd | Real estate | 2020 |
| Stamatex Ltd | Manufacturing | 2017 |
| Stan Hetherington Limited | Wholesale & retail | 1980 |
| Stanhope Road 1959 Limited | Extraterritorial | 2014 |
| Stanmore Joinery Limited | Construction | 2010 |
| Stansbie Commercial Services Limited | Wholesale & retail | 2022 |
| Stanton Bar & Restaurant Ltd | Hospitality | 2026 |
| Stanway Commercials Limited | Manufacturing | 1997 |
| Star LGP Ltd | Hospitality | 2025 |
| STAR2FALL Competitions Ltd | Other services | 2025 |
| Starlite Technologies and Stud Limited | Agriculture & fishing | 2008 |
| Stately Contractors Ltd | Administrative & support | 2019 |
| STATION48 Holdings Limited | Hospitality | 2023 |
| Staworth Limited | Information & communication | 2024 |
| STB Rentals Ltd | Real estate | 2025 |
| STE Alford Carp Fisheries Ltd | Agriculture & fishing | 2013 |
| Stealth and Fitness Ltd | Arts & recreation | 2019 |
| Stealth Property Management Ltd | Households | 2019 |
| Steam and Bean Limited | Hospitality | 2025 |
| Steel River Consultants Limited | Professional & scientific | 2010 |
| Steel River Containers Ltd | Wholesale & retail | 2026 |
| Steel River Cost and Project Management Ltd | Professional & scientific | 2017 |
| Steel River Homes (Oxbridge) Ltd | Construction | 2024 |
| Steel River Investments Ltd | Professional & scientific | 2021 |
| Steeltown Construction Ltd | Construction | 2024 |
| Stellar Consultancy (UK) Limited | Professional & scientific | 2008 |
| Stellify Software Ltd. | Information & communication | 2019 |
| Stenom CIC | Health & social care | 2022 |
| Stenora Ltd | Real estate | 2024 |
| Stephenson Mews Management Company Limited | Households | 2025 |
| Sterling Services NE Ltd | Professional & scientific | 2015 |
| Sterling Timber Frame Ltd | Manufacturing | 2023 |
| Steve Brown NDT Services Limited | Professional & scientific | 2015 |
| Steve Cowell Consulting Ltd | Professional & scientific | 2014 |
| Stevenson NE Limited | Professional & scientific | 2020 |
| Stevenson Property Ltd | Real estate | 2023 |
| Stig RAD Ltd | Health & social care | 2019 |
| Still Breakers Distillery Limited | Manufacturing | 2023 |
| Stillington Tyre Services Ltd | Wholesale & retail | 2025 |
| STL Engineering Limited | Manufacturing | 2021 |
| STM Consultants Ltd | Water & waste | 2013 |
| Stmighty Ltd | Real estate | 2023 |
| Stockbridge Management Alliance Ltd | Administrative & support | 2014 |
| Stockton Alternative Provision CIC | Education | 2025 |
| Stockton and District Advice and Information Service | Information & communication | 2004 |
| Stockton Arts Centre (Trading) Limited | Hospitality | 2015 |
| Stockton Bakery Limited | Manufacturing | 2024 |
| Stockton BID Company Limited | Administrative & support | 2016 |
| Stockton Borough Holding Company Limited | Financial services | 2016 |
| Stockton Business Hub Ltd | Administrative & support | 2020 |
| Stockton Care Limited | Health & social care | 2018 |
| Stockton Chiropractic Clinic Limited | Health & social care | 2011 |
| Stockton E&I Construction Ltd | Construction | 2026 |
| Stockton Enterprise Ltd | Other services | 2024 |
| Stockton Hotels Company Ltd | Hospitality | 2016 |
| Stockton Interiors Limited | Wholesale & retail | 2005 |
| Stockton Learning Centre Ltd | Education | 2017 |
| Stockton Maintenance Services Limited | Real estate | 2023 |
| Stockton Memorials Ltd | Manufacturing | 2025 |
| Stockton NO Property Ltd | Real estate | 2026 |
| Stockton Paving Limited | Construction | 2018 |
| Stockton Property Services Ltd | Real estate | 2022 |
| Stockton Round Table CIC | Other services | 2024 |
| Stockton Rugby Football Club Limited | Arts & recreation | 2019 |
| Stockton Tabernacle Bookshop Limited | Wholesale & retail | 2001 |
| Stockton Turkish Barbers Ltd | Other services | 2025 |
| Stockton Window Centre Builders and Home Improvements Ltd. | Construction | 2020 |
| Stoddart Property Services Limited | Real estate | 2025 |
| Stoked Academy Limited | Arts & recreation | 2024 |
| Stokesley Tractors Ltd | Wholesale & retail | 2012 |
| Stomat Property Limited | Real estate | 2022 |
| Stoneville Properties Ltd | Real estate | 2021 |
| Stopgap Events Ltd | Administrative & support | 2026 |
| Storesurvey Limited | Extraterritorial | 1995 |
| Strachan Project Control Ltd | Professional & scientific | 2014 |
| Strategic Security Group Ltd | Administrative & support | 2017 |
| Stratios Cloud Limited | Information & communication | 2026 |
| Streamline Civil Engineering Limited | Construction | 2009 |
| Striketwice Ltd | Information & communication | 2025 |
| Stuart Hampton Offshore Services Ltd | Professional & scientific | 2018 |
| Stuart Porter Limited | Administrative & support | 2010 |
| Stuart Process Services Limited | Mining & quarrying | 2012 |