| THE Mental Health Path Community Interest Company | Health & social care | 2025 |
| THE North West Herald Limited | Information & communication | 2016 |
| THE Postal Store UK Limited | Transport & logistics | 2021 |
| THE Stone Depot Ltd | Manufacturing | 2022 |
| THE Wholistic Haven Ltd | Hospitality | 2022 |
| THE WOK Inn Ltd | Hospitality | 2022 |
| Thermotraffic (N.I.) Ltd. | Real estate | 1982 |
| Thomas Quigley & SON Limited | Other services | 1997 |
| Three Rivers Search and Rescue C.I.C. | Public administration | 2018 |
| Threefivethree Clothing Limited | Wholesale & retail | 2025 |
| Threesixfour Clothing Limited | Wholesale & retail | 2021 |
| Tirmegan Power Ltd | Energy | 2014 |
| TK Concrete Ltd | Construction | 2014 |
| TLD Enterprises Ltd | Agriculture & fishing | 2024 |
| TMC Stoneworks Ltd | Manufacturing | 2024 |
| Toijala Management Ltd | Real estate | 2005 |
| Tony Finlay Ltd | Information & communication | 2022 |
| Tool Force UK Limited | Wholesale & retail | 2023 |
| Topledge Scaffolding Ltd | Construction | 2024 |
| Total Access & Scaffolding Services Ltd | Construction | 2026 |
| Transparent Solution Software Limited | Information & communication | 2014 |
| Troyswood Limited | Real estate | 2017 |
| TRU Glory Ltd | Wholesale & retail | 2017 |
| Truck and Trailer Leasing Limited | Administrative & support | 2023 |
| TS Haulage Ltd | Transport & logistics | 2024 |
| TS Tanning Ltd | Other services | 2023 |
| Tullywhisker Farms Ltd | Agriculture & fishing | 2025 |
| Tyrone Energy Ltd | Energy | 2008 |
| Urbalreagh Limited | Agriculture & fishing | 2024 |
| Uvape Plus Ltd | Wholesale & retail | 2022 |
| VCI Ltd | Wholesale & retail | 2015 |
| Vibrotect Ltd | Public administration | 2024 |
| Victoria House Enterprises Ltd | Professional & scientific | 2025 |
| Visual Edge Limited | Manufacturing | 1995 |
| VQ Plant Hire and Civil Engineering Limited | Construction | 2013 |
| VQ Property Ltd | Real estate | 2020 |
| W & E Fulton Limited | Agriculture & fishing | 2004 |
| W Doherty Construction Ltd | Construction | 2015 |
| W H Mccormack and Sons Ltd | Wholesale & retail | 2016 |
| Wall to Ceiling Contracts Ltd | Construction | 2023 |
| Walls Engineering Works Ltd | Manufacturing | 2025 |
| WE Bring the Party Limited | Arts & recreation | 2021 |
| Wedderburn Ltd | Wholesale & retail | 2026 |
| Western Group Holdings Ltd | Financial services | 2025 |
| Western Group Ltd | Construction | 2018 |
| Western Group Property Ltd | Households | 2025 |
| Westpoint Consulting Limited | Professional & scientific | 2019 |
| Whats on Your Wall Ltd | Wholesale & retail | 2017 |
| White Strand Investments Ltd | Hospitality | 2019 |
| Whitestar Taxis Limited | Transport & logistics | 2025 |
| William Dunn & SON Ltd | Agriculture & fishing | 2023 |
| Wind Renewables Ltd | Construction | 2012 |
| Woodend Management Company (NI) Ltd | Extraterritorial | 2007 |
| Woodmount Care Home Ltd | Health & social care | 2015 |
| Woodvale Restaurant Limited | Hospitality | 2015 |
| Wray Group Ltd | Wholesale & retail | 2018 |
| Wray Transport Limited | Transport & logistics | 2018 |
| Xpert Recruitment Ltd | Administrative & support | 2022 |
| Yogurt Create Limited | Wholesale & retail | 2026 |
| Young Engineering Specialists Ltd | Professional & scientific | 2022 |
| YUM Yums Express Ltd | Manufacturing | 2025 |