| Srcs Services Limited | Administrative & support | 2007 |
| SUBSTR8 Ltd | Construction | 2017 |
| Supreme Buildings Limited | | 1952 |
| Surgo Construction Limited | Construction | 1928 |
| Sweet Dream Properties Limited | Real estate | 2019 |
| Symetri Limited | Wholesale & retail | 1996 |
| T & T Construction (Cumbria) Ltd | Construction | 2011 |
| T4 Lettings Ltd | Real estate | 2021 |
| Tailored Fire & Security Group Limited | Financial services | 2004 |
| Tamkar Ltd | Hospitality | 2010 |
| Tanneduk Limited | Other services | 2025 |
| Tesmonard Limited | Administrative & support | 2004 |
| THE Luxury Loft Company NE Ltd | Construction | 2022 |
| THE Body Detox Clinic Limited | Other services | 2016 |
| THE Flat Nose Beer Co Ltd | Wholesale & retail | 2025 |
| THE Hardman Centre | Other services | 2011 |
| THE Moth Box Limited | Hospitality | 2012 |
| THE Naked Deli Ltd | Hospitality | 2012 |
| THE Northumbrian Educational Trust Ltd | Education | 1960 |
| THE One Collection Group Ltd | Financial services | 2020 |
| THE Really Easy Group Limited | Wholesale & retail | 2015 |
| THE Social Market Holdings Ltd | Financial services | 2023 |
| Thornton Street Properties Limited | Real estate | 2005 |
| TIC Trading Limited | Wholesale & retail | 2007 |
| Tinsley Special Products Limited | Manufacturing | 2007 |
| Together Energy (Retail) Limited | Energy | 2016 |
| Trees CAN Dance Ltd | Administrative & support | 2024 |
| Trussted Group Ltd | Arts & recreation | 2026 |
| Tyne and Wear Building Preservation Trust Limited | Arts & recreation | 1979 |
| Tyne Fancy Goods Wholesale Limited | Wholesale & retail | 1981 |
| UK Eco Hub Ltd | Other services | 2019 |
| Union Motors NE Limited | Wholesale & retail | 2018 |
| Utopia Homes Limited | Construction | 2023 |
| Vadison Capital Ltd | Financial services | 2026 |
| Value Gate Analytics Limited | Information & communication | 2024 |
| Virgin Money Giving Limited | Professional & scientific | 1992 |
| Virgin Money Holdings (UK) Limited | Financial services | 1995 |
| Virgin Money Limited | Professional & scientific | 2009 |
| Virgin Money Personal Financial Service Limited | Professional & scientific | 1995 |
| Wave Direct Limited | Wholesale & retail | 2017 |
| WE ARE Melt Limited | Wholesale & retail | 2022 |
| Wollemi Forestry Limited | Agriculture & fishing | 2016 |
| Wolsingham Pharmacy Limited | Wholesale & retail | 1996 |
| World Spice Museum CIC | Arts & recreation | 2023 |
| Wyvis House Care Home Ltd | Health & social care | 2005 |
| Ycbps Property Nominee Company Limited | Administrative & support | 1993 |
| Yieldwise Ltd | Real estate | 2020 |
| Yorkshire Bank Limited | Professional & scientific | 1911 |
| Zapatista Limited | Hospitality | 2012 |
| Zdwebsites Ltd | Information & communication | 2020 |