| Starry International Investment Limited | Hospitality | 2022 |
| Stars Youth and Community CIC | Education | 2016 |
| Stephen Carter Limited | Construction | 2014 |
| Sterling Paving & Groundworks Limited | Construction | 2013 |
| Steven Jackson Financial Services NE Ltd | Financial services | 2020 |
| Stoneford Consultants Ltd | Information & communication | 2025 |
| Storage Systems Ltd | Administrative & support | 2015 |
| Strategic Creative Marketing Limited | Other services | 2013 |
| Strong by Nature LNS Ltd | Wholesale & retail | 2023 |
| Stuart Leach Associates Limited | Professional & scientific | 2022 |
| Styled by Juliette Ltd | Professional & scientific | 2022 |
| Styling Boutique Ltd | Other services | 2020 |
| Substation Solutions Ltd | Professional & scientific | 2026 |
| Sunequip Limited | Agriculture & fishing | 1998 |
| Surefire Searches Limited | Administrative & support | 2015 |
| Swann Facilities Management Ltd | Administrative & support | 2026 |
| Swansfield Trading Limited | Wholesale & retail | 2014 |
| Sweet Concept Ltd | Information & communication | 2023 |
| Sweet Snowsports Limited | Arts & recreation | 2012 |
| Swiss Mountain Rescue Limited | Health & social care | 2021 |
| T & C Linnett Limited | Wholesale & retail | 1996 |
| T and T London Limited | Professional & scientific | 2016 |
| T C & Sons Car Sales & Recovery Ltd | Wholesale & retail | 2019 |
| T S Automotive Ltd | Wholesale & retail | 2021 |
| T.U.C. Plant Hire Limited | Administrative & support | 2001 |
| Tabbouleh Ltd | Hospitality | 2024 |
| Tabbouleh ST Ltd | Hospitality | 2023 |
| Tailored Developments NE Ltd | Construction | 2021 |
| Tall Tree Epos Ltd | Administrative & support | 2025 |
| TAN World North East Ltd | Wholesale & retail | 2011 |
| Tanfield 4X4 LRS & Tyres Ltd | Wholesale & retail | 2024 |
| Tanfield Grange Developments Limited | Construction | 2021 |
| Tanfield Laser Cutting Ltd | Manufacturing | 2020 |
| Tanfield Site Services Limited | Construction | 2025 |
| Tankserv UK Ltd | Manufacturing | 2025 |
| TAT.2.95 Limited | Arts & recreation | 2020 |
| Taylor'D Renovations Ltd | Construction | 2015 |
| Taylors Travel Management Ltd | Administrative & support | 2025 |
| TC Harlands Accountants Limited | Professional & scientific | 2024 |
| TCS Plant and Commercial Limited | Wholesale & retail | 2024 |
| Team Valley Picture Framing Co Ltd | Administrative & support | 2005 |
| Ted's Storage Limited | Transport & logistics | 2023 |
| Teichō Ltd | Professional & scientific | 2026 |
| Telemtech Ltd | Professional & scientific | 2023 |
| Tendercare Boarding Kennels and Cattery Ltd | Hospitality | 2021 |
| Tennis IS Served Limited | Arts & recreation | 2020 |
| Tenth Master Ltd | Wholesale & retail | 2025 |
| Tetaro Limited | Hospitality | 2020 |
| TFB Trading Limited | Wholesale & retail | 2025 |
| TH' Tulip Tree Ltd | Wholesale & retail | 2012 |
| Thanvith Convenient Store Ltd | Wholesale & retail | 2026 |
| THE 4 Decades Group Limited | Arts & recreation | 2025 |
| THE Burrow Licensed Tearoom Limited | Hospitality | 2016 |
| THE Care and Support Group (Manchester) Ltd | Health & social care | 2025 |
| THE Care and Support Group Ltd | Health & social care | 2014 |
| THE Courtyard Group NE Ltd | Real estate | 2022 |
| THE Durham Traders Ltd | Wholesale & retail | 2024 |
| THE G-House Barbering Ltd | Other services | 2023 |
| THE Grooming Station Ltd | Other services | 2025 |
| THE HBB Collective Ltd | Professional & scientific | 2025 |
| THE Hectare Group Ltd | Real estate | 2023 |
| THE Housing Coach Community Interest Company | Education | 2026 |
| THE Imperial Bar & Restaurant Ltd | Hospitality | 2025 |
| THE Macro Kitchen (North East) Limited | Hospitality | 2023 |
| THE One Collection Leisure Ltd | Financial services | 2019 |
| THE Ouseburn Market Limited | Wholesale & retail | 2024 |
| THE Pasta Castle Ltd | Manufacturing | 2013 |
| THE Peacock Inn (Tanfield) Ltd | Hospitality | 2005 |
| THE RAT Hole Ltd | Hospitality | 2025 |
| THE Sarnie Shop Ltd | Wholesale & retail | 2019 |
| THE Vault Unlocking Potential CIC | Health & social care | 2025 |
| THE Very Peachy Chef Ltd | Hospitality | 2023 |
| THE Willow Murray Ltd | Professional & scientific | 2024 |
| THE Wolf DEN - Gym & Fitness Ltd | Arts & recreation | 2024 |
| Thefarmhouse Limited | Information & communication | 2016 |
| Theresa Spinks Limited | Manufacturing | 2000 |
| Thesis Limited | Information & communication | 2025 |
| This Consulting Limited | Real estate | 2020 |
| Thompson Tree Services (North East) Ltd | Agriculture & fishing | 2019 |
| Thompson Truck & Trailer Ltd | Wholesale & retail | 2026 |
| Thompsons Vehicle Repair Limited | Wholesale & retail | 2026 |
| Thoric Solutions Ltd. | Information & communication | 2015 |
| Thorogood Homes Ltd | Real estate | 2025 |
| Tiger Tyre Group Ltd | Wholesale & retail | 2025 |
| Tigers Nest Developments Limited | Real estate | 2018 |
| Tindale and Punton Construction Services Ltd | Construction | 2024 |
| Tinkerland Limited | Real estate | 2021 |
| Tiny Tidal Ltd | Information & communication | 2022 |
| Tinyveg Ltd | Agriculture & fishing | 2019 |
| TKD Fit Ltd | Other services | 2017 |
| TLR Medical Limited | Wholesale & retail | 2025 |
| TLR Properties Ltd | Real estate | 2022 |
| TMG Industrial UK Limited | Wholesale & retail | 2026 |
| TOM Asher & Associates Ltd | Real estate | 2026 |
| Tomlinson Gray Limited | Real estate | 1946 |
| Toni and Momo Limited | Real estate | 2021 |
| Tonn Living Limited | Real estate | 2026 |
| Tonn Stay Limited | Real estate | 2025 |
| Top Barber Stanley Ltd | Other services | 2020 |
| Top House Leisure Ltd | Hospitality | 2021 |