| Stockton Angling Limited | Arts & recreation | 2004 |
| Stone Grange Investments Limited | Construction | 1998 |
| Stone Inspecton Limited | Professional & scientific | 2025 |
| Stone NE Ltd | Extraterritorial | 2024 |
| Stonebrooke Estates Ltd | Real estate | 2025 |
| Stonemark Limited | Financial services | 2025 |
| Storm Drain Limited | Financial services | 2020 |
| Storm Lettings Ltd | Real estate | 2020 |
| Storm Property C & S Ltd | Real estate | 2021 |
| Storm Property Solutions Limited | Real estate | 2016 |
| Stott Fitness CIC | Arts & recreation | 2017 |
| Stott Holdings Limited | Extraterritorial | 1998 |
| Stove Essentials Ltd | Wholesale & retail | 2025 |
| Straight Timber Ltd | Construction | 2025 |
| Stranton D.I.Y. Limited | Wholesale & retail | 2019 |
| Stranton Energy Services Limited | Professional & scientific | 2011 |
| Stranton Pets Ltd | Wholesale & retail | 2024 |
| Stranton Property Developments Ltd | Real estate | 2021 |
| Streetzen Ltd | Wholesale & retail | 2023 |
| Strokes Ahead Ltd | Education | 2020 |
| Stryder Technical Services Limited | Professional & scientific | 2018 |
| STU Douglas Services Ltd | Manufacturing | 2023 |
| Stuart Cottnam Joinery Limited | Construction | 2018 |
| Studio 21 Holdings Ltd | Real estate | 2026 |
| Studio 21 Wellness Ltd | Arts & recreation | 2026 |
| Studio 31 (NE) Limited | Other services | 2025 |
| Studio Fara Ltd | Information & communication | 2025 |
| Studio Two Group Limited | Professional & scientific | 2024 |
| Studio Viral Limited | Information & communication | 2023 |
| Studiochill Ltd | Professional & scientific | 2024 |
| Stupid Good Pizza Limited | Hospitality | 2026 |
| STW Associates Ltd | Professional & scientific | 2020 |
| STW Clearance Ltd | Wholesale & retail | 2023 |
| Sugas Private Ltd | Wholesale & retail | 2025 |
| Suggitt and Co Ltd | Information & communication | 2023 |
| Suhka Takeaway Ltd | Hospitality | 2023 |
| SULTANS93 York RD Ltd | Hospitality | 2026 |
| Suman Services Limited | Administrative & support | 2019 |
| Summitlane Ltd | Extraterritorial | 2026 |
| Sun Travel Limited | Extraterritorial | 1990 |
| Sunbox Group Ltd | Energy | 2020 |
| Suncentre Limited | Extraterritorial | 1995 |
| Sunrise Solutions Group Ltd | Energy | 2019 |
| Supercharged Promotions Ltd | Arts & recreation | 2025 |
| SUPREMESERVICES82 Ltd | Construction | 2025 |
| Sure Build North East Limited | Construction | 2026 |
| Surega Limited | Wholesale & retail | 2026 |
| Surega Properties Limited | Real estate | 2026 |
| Surepath Consultancy Services Ltd | Information & communication | 2026 |
| Surface Smart Limited | Administrative & support | 2016 |
| Sutherland Consulting Group Limited | Professional & scientific | 2025 |
| Sutton's Telecommunication Engineers Limited | Information & communication | 2026 |
| Svape Ltd | Manufacturing | 2019 |
| Swayes Hybrid Ltd | Real estate | 2018 |
| Swayes Management Services Limited | Real estate | 2010 |
| Sweat Hybrid Gym Ltd | Arts & recreation | 2025 |
| Sweet Dreams Hartlepool Ltd | Hospitality | 2021 |
| Sweet Munchies Ltd | Wholesale & retail | 2018 |
| Sweeting Rentals Ltd | Real estate | 2026 |
| Swimhaven Limited | Education | 2025 |
| Switch Electrical NE Ltd | Construction | 2024 |
| Sybr Consulting Limited | Information & communication | 2017 |
| Sycamore Gardening Limited | Administrative & support | 2024 |
| Systems North East Limited | | 1986 |
| T & C Technical Consultant Ltd | Extraterritorial | 2022 |
| T & G Direct Funeral Services Ltd | Other services | 2023 |
| T & J Roofing & Building Ltd | Construction | 2025 |
| T & L M Scheduling Limited | Professional & scientific | 2014 |
| T and H Landscaping Ltd | Construction | 2023 |
| T Collins (NE) Limited | Construction | 2015 |
| T I a Light Haulage Limited | Transport & logistics | 2006 |
| T Maxwell Services Ltd | Construction | 2025 |
| T Simpson Transport Limited | Transport & logistics | 2008 |
| T&D Lifting Services Ltd | Construction | 2017 |
| T. I'A Storage Limited | Transport & logistics | 2006 |
| T.D.H. Group Ltd | Arts & recreation | 1991 |
| T.F. & S. Ryan Haulage Limited | Transport & logistics | 2003 |
| T.I.S Gmbh-Testing & Inspection Services Ltd | Professional & scientific | 2022 |
| Talk Business Solutions Limited | Information & communication | 2010 |
| Tallulah Love Limited | Manufacturing | 2009 |
| Tanarife Solarium Limited | Arts & recreation | 2018 |
| Tangent Construction Limited | Construction | 2000 |
| Tanglewood Games Limited | Information & communication | 2017 |
| Taog Limited | Wholesale & retail | 2025 |
| Taxi Direct Ltd | Other services | 2017 |
| Taylor Automation Solutions Ltd | Professional & scientific | 2024 |
| Taylor Gordon Limited | Construction | 2021 |
| Taylor Roche Developments Ltd | Construction | 2024 |
| Tb&Tb Ventures Limited | Information & communication | 2023 |
| TBI Holdings Limited | Financial services | 2017 |
| TBI Investments (2021) Limited | Administrative & support | 2021 |
| TBI Investments Limited | Professional & scientific | 2017 |
| Tbullz Ltd | Transport & logistics | 2026 |
| TCF Medical Ltd | Health & social care | 2018 |
| Tcgs@Hart Ltd | Wholesale & retail | 2025 |
| TCW Yacht Painters Ltd | Construction | 2018 |
| TD Property Management Services Limited | Real estate | 2008 |
| TD Trade NE Limited | Other services | 2025 |
| Tdlm HPL Ltd | Hospitality | 2025 |
| TDM Inspection Limited | Manufacturing | 2022 |