| T Chambers & Sons (Lisnaskea) Limited | Real estate | 2025 |
| T Chambers & Sons (Rossorry) Limited | Real estate | 2025 |
| T Weir Electrical Ltd | Construction | 2025 |
| T. Dickey & Co Limited | Manufacturing | 2004 |
| Tailored Distribution Ltd | Wholesale & retail | 2021 |
| Tarlum Farms Ltd | Agriculture & fishing | 2018 |
| TAS Mechanical Limited | Construction | 2018 |
| Tattygare Trading Ltd | Wholesale & retail | 2024 |
| Tawnalary Limited | Real estate | 2014 |
| Tcts Group Limited | Professional & scientific | 2016 |
| TDM Contracts Limited | Construction | 2026 |
| Techdoc Repairs Ltd | Other services | 2019 |
| Teemore Agricultural Ltd | Wholesale & retail | 2016 |
| Teemore Engineering Limited | Manufacturing | 2007 |
| Teemore Enterprise Ltd | Real estate | 2005 |
| Teemore Holdings Limited | Financial services | 2016 |
| Teemore Landscaping Ltd | Administrative & support | 2025 |
| Teemore Stores Limited | Wholesale & retail | 2025 |
| Teemore Tiling Limited | Construction | 2023 |
| Tempo Glass Ltd | Wholesale & retail | 2005 |
| Tempo Technologies Limited | Information & communication | 2016 |
| TEN Talents Properties Limited | Real estate | 2006 |
| Tescimo Limited | Extraterritorial | 2014 |
| Testall Limited | Construction | 2014 |
| TGF Coaching Ltd | Arts & recreation | 2023 |
| THE 365 Athlete Ltd | Other services | 2024 |
| THE Anxiety App Ltd | Health & social care | 2022 |
| THE Artisan Club Ltd | Manufacturing | 2020 |
| THE Awakened Dreamer Limited | Other services | 2025 |
| THE Billion Globe Inc - Ltd | Wholesale & retail | 2019 |
| THE Butcher Shop Co. Ltd | Real estate | 2005 |
| THE Classy COW Limited | Wholesale & retail | 2016 |
| THE Cornerstone Bar Limited | Hospitality | 2023 |
| THE Courthouse Kesh Limited | Education | 2016 |
| THE Cousins Barber Shop Ltd | Other services | 2025 |
| THE Crisp Shack Ltd | Hospitality | 2022 |
| THE Culture Hutch Ltd | Professional & scientific | 2024 |
| THE Douglas Garage Ltd | Wholesale & retail | 2021 |
| THE ELY Centre Limited | Health & social care | 2002 |
| THE Empowered Soul Sisters Ltd | Other services | 2023 |
| THE Fabric Library (Enniskillen) Limited | Wholesale & retail | 2006 |
| THE Forge Takeaway 40 Limited | Hospitality | 2026 |
| THE Furniture Gallery (Enniskillen) Limited | Wholesale & retail | 2024 |
| THE Healthy Pet Food Company Limited | Wholesale & retail | 2014 |
| THE Hire Game Ltd | Administrative & support | 2026 |
| THE Kings of the Road Limited | Wholesale & retail | 2025 |
| THE Lough Inn Ltd | Hospitality | 2019 |
| THE Luto Clinic Ltd | Health & social care | 2025 |
| THE Mane Barbershop Ltd | Other services | 2026 |
| THE Merry Mare (NI) Limited | Hospitality | 2019 |
| THE Natural Beauty POT Ltd | Wholesale & retail | 2021 |
| THE Painted PIG Limited | Manufacturing | 2020 |
| THE Power House by RK Ltd | Arts & recreation | 2025 |
| THE Pre-School and Afterschool at Holy Trinity (EKN) Limited | Education | 2018 |
| THE RUG Wholesaler Limited | Wholesale & retail | 2019 |
| THE Skin Clinic (NI) Limited | Health & social care | 2017 |
| THE Stables Roslea Ltd | Arts & recreation | 2024 |
| THE Thatch Coffee Shop Ltd | Hospitality | 2025 |
| THE Tilery Limited | Health & social care | 2003 |
| THE Toastery Ltd | Hospitality | 2021 |
| THE Wild Stag Restaurant Ltd | Hospitality | 2025 |
| Thechipshop Ltd | Hospitality | 2019 |
| Them Again Productions Ltd | Information & communication | 2017 |
| Thomas Hanna & Co. Ltd | Construction | 2003 |
| Thompson Bruce Steel Limited | Construction | 2017 |
| Thompson Plant Services Ltd | Manufacturing | 2026 |
| Threesixtyfour Ltd | Information & communication | 2018 |
| Thrive Online Fitness Ltd | Arts & recreation | 2023 |
| Thriving Coaching Ltd | Arts & recreation | 2025 |
| Tickety-Moo Wholesale Limited | Wholesale & retail | 2015 |
| Tierney Homes Ltd | Health & social care | 2023 |
| Tierney Tax Consultancy (NI) Limited | Professional & scientific | 2016 |
| Tilermade Limited | Wholesale & retail | 2020 |
| Timepiece Prestige Ltd | Wholesale & retail | 2023 |
| Timetotrade Ltd | Information & communication | 2023 |
| Timoney Windows and Conservatories Limited | Construction | 2017 |
| Tiny Tots Cross Community Playgroup | Education | 2006 |
| Tivnacree Farms Limited | Agriculture & fishing | 2023 |
| Tjmau Kitchens Ltd | Manufacturing | 2025 |
| Tjmau Services Limited | Construction | 2024 |
| TLC Compliance Limited | Transport & logistics | 2020 |
| Tltg Ltd | Professional & scientific | 2023 |
| TM Drinks Ltd | Wholesale & retail | 2024 |
| TMC PT Limited | Arts & recreation | 2019 |
| TMD Rental Properties Limited | Real estate | 2025 |
| Tmec Holdings Limited | Financial services | 2023 |
| Tminc Ltd | Manufacturing | 2025 |
| Tocopa Investments Ltd | Real estate | 2012 |
| Toneywall Ltd | Construction | 2016 |
| Tony Danielle & Co. Limited | Manufacturing | 2018 |
| Tonystick Mews Management Company Limited | Households | 1992 |
| Topchem Solutions Limited | Manufacturing | 2019 |
| Tosaigh NUA Limited | Professional & scientific | 2020 |
| Total Pipeline Test Solutions Limited | Construction | 2016 |
| Total Weed Control Ireland Limited | Professional & scientific | 2025 |
| TP Music Group Ltd | Arts & recreation | 2023 |
| Tracey Brothers Limited | Construction | 1998 |
| Tracey Concrete Limited | Manufacturing | 1979 |
| Tracey Plant (NI) Limited | Administrative & support | 2018 |
| Tradingengine Ltd | Information & communication | 2022 |