| Taste Joy Company Ltd | Manufacturing | 2021 |
| Team Kartsport Ltd | Arts & recreation | 2018 |
| TEC Engineering Limited | Manufacturing | 2009 |
| Technigrove Advisors Limited | Wholesale & retail | 2020 |
| Telatec Ltd | Information & communication | 2002 |
| Teng 2025 Ltd | Hospitality | 2025 |
| Texpro Ltd | Wholesale & retail | 1995 |
| Texrho Limited | Extraterritorial | 1985 |
| THE Bedrock Group Limited | Information & communication | 2014 |
| THE Belfry Deli Ltd | Hospitality | 2003 |
| THE Bothans Cabins NI Ltd | Hospitality | 2023 |
| THE Care College (PVT) Ltd | Extraterritorial | 2012 |
| THE Central Bar Garvagh Ltd | Hospitality | 2023 |
| THE Crannagh Management Ltd | Households | 2018 |
| THE Crescent (Coleraine) Management Company Limited | Real estate | 2017 |
| THE Cultured Code Ltd | Information & communication | 2025 |
| THE Distillers View Ltd | Real estate | 2025 |
| THE Employment Service Limited | Professional & scientific | 2020 |
| THE Flax Room Ltd | Hospitality | 2025 |
| THE Foundry Vault Ltd | Transport & logistics | 2021 |
| THE Gate Automation Co (NI) Limited | Manufacturing | 2011 |
| THE Good Shutter Company Ltd | Wholesale & retail | 2019 |
| THE Gym Locker Ltd | Wholesale & retail | 2025 |
| THE Island Equestrian Centre LLP | | 2013 |
| THE Johnston Clear Settlement Company Ltd | Extraterritorial | 2015 |
| THE Johnston Family Settlement Company Ltd | Extraterritorial | 2015 |
| THE Johnston Lisclare Settlement Company Ltd | Extraterritorial | 2015 |
| THE LCA Agency Ltd | Professional & scientific | 2015 |
| THE Lobster & Crabs Settlement Company Ltd | Extraterritorial | 2015 |
| THE Loft Cafe Bistro Ltd | Hospitality | 2025 |
| THE Meadows Bellaghy Ltd | Real estate | 2014 |
| THE Method Consortium Ltd | Financial services | 2024 |
| THE Mews Bushmills Management Ltd | Households | 2018 |
| THE Orchards Land Management Ltd | Households | 2016 |
| THE Paddocks (Ramoan) Management Company Limited | Households | 2008 |
| THE Parcel Depot Ltd | Wholesale & retail | 2017 |
| THE Perch North Coast Limited | Hospitality | 2022 |
| THE Perfect Extras Ltd | Hospitality | 2025 |
| THE Pizza Box Kilrea Limited | Hospitality | 2022 |
| THE Plumbfall Management Company Ltd | Households | 2022 |
| THE Real Health Store Ltd | Wholesale & retail | 2019 |
| THE Smyth Charitable Trust | Other services | 2019 |
| THE Tides Management Company Ltd | Households | 2022 |
| THE Tread Shed Ltd | Wholesale & retail | 2010 |
| THE VET Service Ltd | Professional & scientific | 2018 |
| THE View Management (N.I.) Ltd | Households | 2016 |
| THE Vintage GUY N.I. Ltd | Wholesale & retail | 2024 |
| THE Whins Management Limited | Households | 2003 |
| Thorndyke Ltd | Real estate | 2022 |
| Threec Wellness Service Ltd | Education | 2021 |
| Tiercon Construction Limited | Construction | 2013 |
| Tigk Property Ltd | Real estate | 2025 |
| TLC Properties Ltd | Real estate | 1999 |
| TNH Ltd | Financial services | 2020 |
| TNT Coleraine Ltd | Hospitality | 2024 |
| Tober Limited | Real estate | 2001 |
| Tonnta Films Ltd | Information & communication | 2025 |
| Tony's Nails & Spa Limited | Other services | 2024 |
| Tony’S Nails & Spa 29 Limited | Other services | 2025 |
| Tooltech Industrial Equipment Ltd | Manufacturing | 2008 |
| Top Darts Ltd | Arts & recreation | 2025 |
| Torreq Limited | Financial services | 2026 |
| Total Dental Hygiene Limited | Health & social care | 2018 |
| Tremor Games Ltd | Information & communication | 2024 |
| Triangle Castles Limited | Administrative & support | 2022 |
| Triex Energy Limited | Construction | 2020 |
| Trinity Overwatch Ltd | Administrative & support | 2025 |
| Trution Jing Ltd | Wholesale & retail | 2025 |
| Tullagh Dale Land Management Ltd | Households | 2002 |
| Tullyarton 1963 Limited | Extraterritorial | 2013 |
| Tullymore Bar & Restaurant Limited | Hospitality | 2017 |
| Tullymore Dale Property Management Limited | Real estate | 2010 |
| Tullymore Hotels Limited | Hospitality | 2016 |
| Turkish Kebab & Pizza Ltd | Hospitality | 2020 |
| Turley Legal Ltd | Professional & scientific | 2020 |
| Tweedak Group Limited | Professional & scientific | 1961 |
| Twelve Fifty Two Ltd | Other services | 2018 |
| Twentytwofour Design and Development Ltd | Information & communication | 2024 |
| Twomac Properties Limited | Administrative & support | 2012 |
| Ucar (NI) Ltd | Wholesale & retail | 2014 |
| Ulster P.V.C. Limited | Manufacturing | 1971 |
| Ulster Retail Limited | Wholesale & retail | 2014 |
| Unohuman Ltd | Administrative & support | 2023 |
| URL Results | Information & communication | 2011 |
| VAC Foods Ltd | Hospitality | 2023 |
| Van Life Shop Limited | Wholesale & retail | 2022 |
| Vaporotech Limited | Administrative & support | 2010 |
| Varghese Holdings UK Limited | Information & communication | 2021 |
| Vertiwindtech Ltd | Extraterritorial | 2011 |
| Vicara Ltd | Health & social care | 2025 |
| Vineyard Compassion | Other services | 2012 |
| Vitality Lifestyle Ltd | Financial services | 2023 |
| Viveo AI Ltd | Information & communication | 2024 |
| Vornet Ltd | Wholesale & retail | 2025 |
| W. Oliver (Exorna) Limited | Manufacturing | 1983 |
| W.S. Doey Building Contractors Ltd | Construction | 2013 |
| Walworth BK Limited | Construction | 2012 |
| Wastebeater (Belfast) Limited | Water & waste | 2016 |
| Watergate Quay (NO.1) Management Company Limited | Households | 2008 |
| Waters Edge Property Management Limited | Extraterritorial | 2006 |