| Greenhill Haulage Ltd | Transport & logistics | 2010 |
| Greenhill Landscaping Limited | Administrative & support | 2024 |
| Greenhill Systems Limited | Wholesale & retail | 2019 |
| Greenlane Cloud Solutions Ltd | Information & communication | 2026 |
| Greenmount Construction Limited | Construction | 2011 |
| Greenmount Place Management Company Limited | Administrative & support | 2010 |
| Greenmount Property Development (Pennybridge) Ltd | Real estate | 1996 |
| Greyfriars Developments (N.I.) Ltd | Real estate | 2021 |
| Greyhound Security Solutions Ltd | Administrative & support | 2025 |
| GRH Contracts Limited | Construction | 2017 |
| Grid Management Ltd | Professional & scientific | 2025 |
| Grovehill Property Investments Limited | Real estate | 2025 |
| GS Motorcycles Ltd | Wholesale & retail | 2003 |
| GSC Computers IE Ltd | Wholesale & retail | 2024 |
| GSC Computers Ltd | Wholesale & retail | 2018 |
| GSS (NI) Limited | Information & communication | 2011 |
| GWW Electrical Ltd | Construction | 2020 |
| Gymfit (N.I.) Limited | Extraterritorial | 2023 |
| H & M Mckeown Supplies Limited | Wholesale & retail | 2004 |
| H. Mclarnon & SON Ltd | Construction | 2004 |
| H.M.C. Global Limited | Professional & scientific | 2000 |
| H2 Energy Limited | Manufacturing | 2012 |
| H2O Swimming Academy Ltd | Arts & recreation | 2016 |
| H2O Swimming Academy RF Limited | Arts & recreation | 2021 |
| Hackermouse Ltd | Hospitality | 2023 |
| Hackthehub Ltd | Information & communication | 2017 |
| Hamac Holdings Limited | Financial services | 2024 |
| Hamac Imports Limited | Extraterritorial | 2007 |
| Hamac Recycling Limited | Water & waste | 2021 |
| Hamilton Carpentry Solutions Ltd | Construction | 2014 |
| Hamilton Telecoms Ltd. | Construction | 2024 |
| Happiness Villages Limited | Construction | 2022 |
| Happy Villa Galgorm Limited | Hospitality | 2020 |
| Harbour Road Management Ltd | Households | 2024 |
| Hardy Brothers Wholesale Ltd | Wholesale & retail | 2018 |
| Hare Energy Limited | Professional & scientific | 2018 |
| Harmony House Ricky Ltd | Hospitality | 2022 |
| Harphall Poultry Ltd | Agriculture & fishing | 2015 |
| Harry Clarke & Company Limited | Real estate | 2017 |
| Harry Dunlop Refrigeration Europe Ltd | Wholesale & retail | 2008 |
| Harryville Housing Association Ltd | Health & social care | 2005 |
| Harvey Formwork Ltd | Manufacturing | 2015 |
| Hazelbank Homestead Limited | Construction | 2005 |
| HCW Properties Limited | Administrative & support | 2016 |
| Healthcare DNA Limited | Health & social care | 2021 |
| Healthy Rhythms Coaching Ltd | Health & social care | 2023 |
| Hearson & Mitchell Country Clothing Ltd | Wholesale & retail | 2025 |
| Heating and Energy Solutions Ltd | Construction | 2021 |
| Heggarty Co Limited | Professional & scientific | 2018 |
| Helen Mcburney Skincare Ltd | Other services | 2021 |
| Heli SPE OPS Ltd | Transport & logistics | 2025 |
| Hendron (N.I.) Ltd | Professional & scientific | 2025 |
| Hendron Ltd | Professional & scientific | 2021 |
| Henry Thomson Limited | Extraterritorial | 1955 |
| Henryville Apartments Management Company Limited | Households | 2025 |
| Heritage Traditional Building Products Limited | Construction | 2003 |
| Hessington Holdings NI Limited | Financial services | 2019 |
| HFK Property Ltd | Real estate | 2021 |
| Hiddenloop Ltd | Information & communication | 2005 |
| Highway Health Group Ltd | Health & social care | 2023 |
| Hilden Pharmacy Limited | Wholesale & retail | 2004 |
| Hill Street Trading Ltd | Hospitality | 2022 |
| Hillmount Farm LLP | | 2021 |
| Hilltop Freerange Ltd | Agriculture & fishing | 2024 |
| Hiltonstown Simmentals Limited | Agriculture & fishing | 2018 |
| Hinnao International Ltd | Manufacturing | 2024 |
| Hire a Skip | Water & waste | 2021 |
| Hire Fitness Ireland Ltd | Administrative & support | 2021 |
| Hivealpha Ltd | Information & communication | 2025 |
| HMC Marketing Ltd | Professional & scientific | 2022 |
| Hogg Contracts Ltd | Construction | 2025 |
| Holestone Catering Ltd | Hospitality | 2023 |
| Holestone Restaurant Ltd | Hospitality | 2022 |
| Holywood Leisure Limited | Information & communication | 1997 |
| Home Improvements Trade Supplies Limited | Wholesale & retail | 2024 |
| Homeport Candles Limited | Wholesale & retail | 2024 |
| Homes Independent Lettings Ltd | Real estate | 2023 |
| Homesure Property Management Ltd | Construction | 2012 |
| Honeybees Playground Ltd | Arts & recreation | 2024 |
| Honeybees Playtown Ltd | Arts & recreation | 2021 |
| Honeycrown Property and Assets Management Ltd | Real estate | 2023 |
| Hope for Body and Soul Ltd | Education | 2024 |
| Horizon Business Village (Weybridge) Ltd | Real estate | 2002 |
| Horse Transport Professionals Ltd | Agriculture & fishing | 2021 |
| Hot CHA 37 Ltd | Hospitality | 2023 |
| House of Reflexology Limited | Health & social care | 2024 |
| House Sliding Wardrobes & Floors Ltd | Wholesale & retail | 2020 |
| Houston Hair 2 Ltd | Other services | 2018 |
| HS Solid Fuels Limited | Wholesale & retail | 2018 |
| HSM (NI) Limited | Wholesale & retail | 2013 |
| HTM Motorcycles Ltd | Wholesale & retail | 2021 |
| Hub Warehousing Ltd | Transport & logistics | 2023 |
| Huge Rugby Ltd | Wholesale & retail | 2013 |
| Hugomont Ltd | Real estate | 2024 |
| Hull's of Ballymena Ltd | Wholesale & retail | 2020 |
| Hunter a Limited | Wholesale & retail | 2015 |
| Hunters Maintenance Ltd | Construction | 2022 |
| I.V.O Supply Company Ltd | Wholesale & retail | 2024 |
| Icev PTY Ltd | Construction | 2026 |
| Illi Management Limited | Real estate | 2021 |