| Stmw Holdings Ltd | Financial services | 2025 |
| STO Express (Newcastle) Ltd | Transport & logistics | 2016 |
| Stocked Hub Limited | Wholesale & retail | 2025 |
| Stockswood Estates Ltd | Real estate | 2015 |
| Stockton Mazel TOV Ltd | Extraterritorial | 2010 |
| Stockton on Tees Ltd | Extraterritorial | 2010 |
| Stone Elegance Limited | Manufacturing | 2011 |
| Stone Idols Limited | Professional & scientific | 2009 |
| Stone Mountain Co. Limited | Real estate | 2019 |
| Stonehills Services Limited | Hospitality | 1988 |
| Stonewold Ceramics Import and Distribution Ltd | Wholesale & retail | 2025 |
| Stonework Properties Limited | Real estate | 2022 |
| Storage Box Hub Ltd | Wholesale & retail | 2022 |
| Storey Heating Limited | Construction | 2008 |
| Storey International Limited | Financial services | 2025 |
| Storm Promotions and Events Limited | Professional & scientific | 2022 |
| Stottie Ltd | Hospitality | 2026 |
| Stovrite Specialist Coatings Limited | Other services | 2009 |
| Stoyanova Company Limited | Health & social care | 2015 |
| Straightforward Studios Ltd | Information & communication | 2019 |
| Strategic OP Co 2 Limited | Financial services | 2023 |
| Stratton UK Developments Limited | Construction | 2015 |
| Strawberries and Cream Hair Limited | Other services | 2023 |
| Strawberry Banners Ltd | Professional & scientific | 2011 |
| Streetfleet M-O-T Services Limited | Wholesale & retail | 2007 |
| Strike-It North Limited | Other services | 2024 |
| Strobelite Limited | Information & communication | 2021 |
| Stuart Bray Limited | Arts & recreation | 2026 |
| Studio Electric by Blazes Ltd | Wholesale & retail | 2020 |
| Studio Greenwell Ltd | Professional & scientific | 2021 |
| Studio Hush Ltd | Manufacturing | 2008 |
| Studio Sable Ltd | Professional & scientific | 2025 |
| Studio Stunt Double Limited | Professional & scientific | 2011 |
| Study Buddy Resources Ltd | Information & communication | 2025 |
| Studywell Medicine Ltd | Education | 2017 |
| Stylemobile Limited | Other services | 2003 |
| SUB1 Fresh Limited | Other services | 2016 |
| Subly UK Limited | Information & communication | 2020 |
| Subsafe Safety Management Ltd | Health & social care | 2026 |
| Substation Design Applications Limited | Professional & scientific | 2013 |
| Sudasha Investments Ltd | Real estate | 2024 |
| Sudasha Limited | Health & social care | 2012 |
| SUE Holdsworth Therapy Ltd | Health & social care | 2026 |
| SUE Mcclellan Associates Limited | Professional & scientific | 2013 |
| Sugar Coat Art Ltd | Wholesale & retail | 2022 |
| Suite Livin Limited | Hospitality | 2021 |
| Sully Enterprise Limited | Hospitality | 2021 |
| Sully's Events Ltd | Hospitality | 2026 |
| Summer in Paris Ltd | Health & social care | 2026 |
| Summerhill Lane Developments Limited | Construction | 2019 |
| Sumo Drinks Ltd | Manufacturing | 2008 |
| Sun Bear Estates Ltd | Real estate | 2024 |
| SUN737 Ltd | Real estate | 2024 |
| Sunclean Limited | Administrative & support | 1994 |
| Sunderland Air Conditioning Ltd | Extraterritorial | 2025 |
| Sunderland Property Dealers Ltd | Real estate | 2021 |
| Sunderland Property Network Ltd | Information & communication | 2026 |
| Sunnah UK Property’S Ltd | Real estate | 2024 |
| Sunniside Chippy Ltd | Hospitality | 2024 |
| Sunniside Motors Limited | Wholesale & retail | 2023 |
| Sunny Paws Retreat Ltd | Other services | 2026 |
| Sunny Side UP NCL Ltd | Hospitality | 2025 |
| Sunshine Enterprise Group EU Limited | Financial services | 2020 |
| Supalite (North East) Limited | Construction | 2024 |
| Super Natural Events Ltd | Other services | 2021 |
| SUPERFOOD4PETS Limited | Administrative & support | 2014 |
| Superget Ltd | Professional & scientific | 2019 |
| Superior Honey Ltd | Hospitality | 2021 |
| Superior Sealants NE Ltd | Construction | 2023 |
| Superkrush Films Limited | Information & communication | 2006 |
| Superkrush Ltd | Information & communication | 2024 |
| Supersnacks (NE) LLP | | 2012 |
| Support 324 Limited | Professional & scientific | 2015 |
| Surche Barbers Ltd | Other services | 2025 |
| Surge Skills Consulting Ltd | Information & communication | 2023 |
| Suri Ltd | Real estate | 2021 |
| Surrey Pain Services Limited | Health & social care | 2019 |
| Survey and Energy Centre LLP | | 2010 |
| Surveyors Services Limited | Construction | 2007 |
| Sushi Kyoto Gateshead Limited | Hospitality | 2026 |
| Sutton Smith Limited | Professional & scientific | 1986 |
| SW 79 Limited | Professional & scientific | 2021 |
| SW Building (NE) Limited | Construction | 2025 |
| SW Tiling (NE) Ltd | Construction | 2022 |
| Swaadluxe Ltd | Wholesale & retail | 2025 |
| Swales Property NE Ltd | Real estate | 2021 |
| Swan Heworth Ltd | Hospitality | 2025 |
| Swaran Key Ltd | Administrative & support | 2025 |
| Swarm Energy Limited | Information & communication | 2023 |
| Sweet Honey Ltd | Real estate | 2015 |
| Sweet Solstice Ltd | Hospitality | 2021 |
| Sweets Galore Blue Ltd | Wholesale & retail | 2021 |
| Swift Advertising NE Ltd. | Professional & scientific | 2014 |
| Swift Build Experts Ltd | Construction | 2026 |
| Swift Carpet Fitting Limited | Construction | 2015 |
| Swift Electronics Ltd | Manufacturing | 2014 |
| Swift Therapy Limited | Administrative & support | 2010 |
| Swiss Land Limited | Construction | 2006 |
| Switch Electrical & Mechanical Services Ltd. | Manufacturing | 2017 |
| SY26 Ltd | Hospitality | 2026 |