| Stokoe Group Ltd | Real estate | 2023 |
| Storage AI Apps Ltd | Information & communication | 2026 |
| Stradwell Properties Limited | | 1983 |
| Sully's Limited | Extraterritorial | 2007 |
| Sunderland Association Football Club,Limited(The) | Arts & recreation | 1896 |
| Sunderland Furniture Centre Limited | Wholesale & retail | 2003 |
| Sunshop UK Limited | Other services | 2023 |
| Swift 957 Limited | Real estate | 2003 |
| T.S.C. Dobbin Limited | Wholesale & retail | 2000 |
| Tashma Investments Limited | Real estate | 2021 |
| Team Valley Land Rover Service Centre Limited | Professional & scientific | 2007 |
| Team Valley Land Rover Specialists Limited | Professional & scientific | 2007 |
| Teer Properties Ltd | Real estate | 2023 |
| Templetown Salvage Ltd | Wholesale & retail | 2023 |
| THE Dolls Tanning Accelerator Cream Company Limited | Wholesale & retail | 2025 |
| THE Fewer Things Ltd | Education | 2018 |
| THE Little Theatre (Gateshead) Limited | Administrative & support | 1949 |
| THE Mill Inn Rainton Bridge Limited | Hospitality | 2005 |
| THE Style Salon Ltd | Other services | 2024 |
| THE Terrace (Sunderland) Ltd | Hospitality | 2019 |
| THE Tiny Wardrobe Ltd | Wholesale & retail | 2019 |
| THE Tyneside Golf Club Trading Limited | Arts & recreation | 2016 |
| THE Unified Advertising Agency Ltd | Information & communication | 2024 |
| Thornproof Limited | Manufacturing | 1982 |
| Thumb Digital Media Design Limited | Professional & scientific | 2003 |
| Tiger Spice North Limited | Hospitality | 2016 |
| TIM Guiseley Ltd | Professional & scientific | 2007 |
| TJR Licensing Limited | Public administration | 2015 |
| Top Pet Shop Ltd | Wholesale & retail | 2022 |
| Trailspark Limited | Manufacturing | 1988 |
| TSS Stores Ltd | Wholesale & retail | 2026 |
| Tyne Pipe Fabricators Limited | Manufacturing | 1987 |
| Tynemouth Lodge Hotel Limited | Hospitality | 2005 |
| Tynemouth Software LLP | | 2010 |
| Tyneside Domestic Services Ltd | Information & communication | 2022 |
| Tyneside Golf Club Limited(The) | Arts & recreation | 1911 |
| UK Autotech Limited | Wholesale & retail | 2001 |
| UK Time Solutions Limited | Professional & scientific | 2007 |
| UK Wheeliebins .Co.Uk Ltd | Wholesale & retail | 2020 |
| Unipres (UK) Limited | Manufacturing | 1987 |
| Vape Planet Ltd | Manufacturing | 2016 |
| VC Nest Holdings Limited | Real estate | 2023 |
| Vega Lane Trade Limited | Wholesale & retail | 2026 |
| Verano Apartments Management Company Limited | Households | 2002 |
| VIC Young Vehicle Hire Limited | Extraterritorial | 1988 |
| Viking Safety Limited | Wholesale & retail | 1975 |
| Vision Learning Trust Limited | Education | 2016 |
| Wainstone Developments Limited | Construction | 2005 |
| Walkergate & Parkside Limited | Wholesale & retail | 2007 |
| WE Buy Land and Gardens Ltd | Real estate | 2024 |
| Wearside Golf Club (Trading) Limited | Arts & recreation | 2018 |
| Wearside Golf Club Limited(The) | Arts & recreation | 1899 |
| Weatherwise (NE) Ltd | Other services | 2004 |
| Whinstone View Limited | Hospitality | 2021 |
| Whitfield Machinery Limited | Extraterritorial | 1996 |
| Whitley Bay Football Club Limited | Arts & recreation | 1958 |
| Whitley Bay Golf Club Ltd(The) | Arts & recreation | 1912 |
| WMW Group Limited | Manufacturing | 2018 |
| Worr Limited | Manufacturing | 2006 |
| Y4 Ltd | Professional & scientific | 2005 |
| Ygmh | Education | 2021 |
| Ymca North Tyneside | Other services | 1992 |
| Zalam Holdings Limited | Real estate | 2022 |
| Zest Design & Marketing Limited | Professional & scientific | 2007 |
| Ziel Developments Ltd | Construction | 2023 |
| Ziele Properties Ltd | Real estate | 2023 |
| Zuqireta Ltd | Wholesale & retail | 2024 |