| GW Forest & Peatland (NI) Ltd | Agriculture & fishing | 2025 |
| Hackett S Commerce Ltd | Wholesale & retail | 2026 |
| Hadden Maguire Construction Limited | Construction | 2025 |
| Halfway House (Tattyreagh) Ltd | Hospitality | 2021 |
| Hallquar Engineering Services UK Ltd | Construction | 2018 |
| Ham-Con (N.I.) Ltd | Construction | 2015 |
| Hannahstown Bess Ltd | Other services | 2019 |
| Hano Business Solutions Ltd | Professional & scientific | 2025 |
| Happypetsni Limited | Wholesale & retail | 2015 |
| Harinder Home Trading Ltd | Wholesale & retail | 2024 |
| Harte Demolition Ltd | Construction | 2016 |
| Haughey Farms Ltd | Agriculture & fishing | 2018 |
| Haughey Homes (NI) Ltd | Construction | 2023 |
| Hawkes Agri Ltd | Wholesale & retail | 2021 |
| Hawkes Earthworks & Aggregates Ltd | Construction | 2025 |
| Hawkes Machine Tools Ltd | Manufacturing | 2023 |
| Hawkes Transport Ltd | Manufacturing | 2009 |
| Hawkesbury River Properties Limited | Real estate | 2017 |
| Hawks Plant Hire Limited | Transport & logistics | 2022 |
| Hazel Wand Theatre School Ltd | Education | 2021 |
| Hazelburn Poultry Limited | Agriculture & fishing | 2010 |
| HDL Group IRL Ltd | Construction | 2021 |
| Heagney Construction Ltd | Construction | 2020 |
| Heaney Retail Ltd | Wholesale & retail | 2015 |
| Heaney's Bar Ltd | Hospitality | 2021 |
| Heberger Medical Limited | Health & social care | 2025 |
| Heeb Investments Ltd | Financial services | 2012 |
| Hely Burn Management Company Limited | Households | 2022 |
| Herbst Machinery Ltd | Manufacturing | 2004 |
| Herocomps Limited | Arts & recreation | 2024 |
| Herron Medical Limited | Real estate | 2015 |
| Hi-Line Engineering Ltd | Construction | 2009 |
| Highfield Management (Block D) Limited | Real estate | 2008 |
| Hill Valley Medical Limited | Health & social care | 2021 |
| Hillhead Civils Ltd | Construction | 2024 |
| Hillhead Properties Ltd | Construction | 2018 |
| Hillhead Property Investment Ltd | Real estate | 2023 |
| Hillside Logistics Ltd | Financial services | 2022 |
| Hilltop Aggregates Ltd | Mining & quarrying | 2011 |
| Hilltop Agri Ltd | Agriculture & fishing | 2023 |
| Hillview Farm Dromore Ltd | Agriculture & fishing | 2025 |
| Hillview Farm Limited | Agriculture & fishing | 2005 |
| Hillview Lodge Limited | Real estate | 1990 |
| Hillview Plant & Commercials Ltd | Administrative & support | 2003 |
| Hitec Solutions (IRE) Ltd | Construction | 2013 |
| Hmbm Ltd | Financial services | 2019 |
| Hmci Limited | Professional & scientific | 2015 |
| Hodl Vision Group Ltd. | Health & social care | 2015 |
| Hollowpark Poultry Ltd | Agriculture & fishing | 2013 |
| Hollypark Farm Energy Ltd | Energy | 2011 |
| Hollywood Furnishings Limited | Manufacturing | 2009 |
| Holz (N.I.) Ltd | Wholesale & retail | 2023 |
| Home Centre Direct Ltd | Extraterritorial | 2021 |
| Home Xpand Ltd | Construction | 2024 |
| Home-Start Omagh District | Health & social care | 2005 |
| Honestonlinecoaching Limited | Health & social care | 2021 |
| Horizon Facilities Ltd | Financial services | 2014 |
| Hosier Electrical Limited | Extraterritorial | 2023 |
| Hotel RUE Omagh Ltd | Hospitality | 2015 |
| House of Nails Omagh Ltd | Other services | 2025 |
| Houston Roofing Limited | Construction | 2023 |
| Hrkn Limited | Real estate | 2022 |
| HRL Agri Ltd | Agriculture & fishing | 2015 |
| Hsmk Investments Limited | Real estate | 2025 |
| HTM Wigs Ltd | Wholesale & retail | 2025 |
| Huangxiwei Limited | Wholesale & retail | 2024 |
| Hughes Engineering Works Ltd | Manufacturing | 2015 |
| Huiliu Huilui Ltd | Wholesale & retail | 2025 |
| Hungry Ginger Ltd | Hospitality | 2022 |
| Hunter Trading (Omagh) Ltd | Real estate | 2018 |
| Hunter West Activities Ltd | Construction | 2012 |
| Hydro Leak Detection Ltd | Professional & scientific | 2020 |
| Hydro N.Ireland Limited | Professional & scientific | 2011 |
| Hydro-Ion Ltd | Water & waste | 2026 |
| Hydroclean Ltd | Construction | 2005 |
| Hygge Professional Ltd | Other services | 2020 |
| I AM Arcader Ltd | Administrative & support | 2020 |
| I J Trailerspares Limited | Wholesale & retail | 2006 |
| I P Poultry Ltd | Agriculture & fishing | 2017 |
| I Play Phonics Limited | Education | 2025 |
| I.B.A.R.S. & Co. Ltd. | Arts & recreation | 1990 |
| I.Rosebud Ltd | Information & communication | 2014 |
| IAN Short Plumbing & Heating Ltd | Construction | 2006 |
| IB Energy Ltd | Energy | 2011 |
| Iconic Stairs Ltd | Construction | 2015 |
| ID Signs & Graphics Limited | Construction | 2011 |
| Imac Architecture Ltd. | Professional & scientific | 2018 |
| Imac Estates Limited | Administrative & support | 2004 |
| Image Express Print Limited | Wholesale & retail | 2020 |
| Industrial Analytics & Automation Ltd. | Professional & scientific | 2021 |
| Inisclan Inc. Ltd | Financial services | 2021 |
| Inn House Limited | Hospitality | 2006 |
| Inn Village Coffee Ltd | Hospitality | 2019 |
| Innbar Group Ltd | Administrative & support | 2023 |
| Inncoffee Ltd | Hospitality | 2023 |
| Innofarma Ltd | Professional & scientific | 2025 |
| Innovative Container Solutions Ltd | Manufacturing | 2025 |
| Innvillage BK Ltd | Hospitality | 2019 |
| Innvillage Campsie Ltd | Hospitality | 2019 |
| Innvillage Ltd | Hospitality | 2018 |