| HAU HAU Trading Limited | Wholesale & retail | 2023 |
| Hawe Transport Ltd | Transport & logistics | 2025 |
| Hawk Takeaway Limited | Hospitality | 2021 |
| Hawlmark Cleaners Limited | Other services | 2024 |
| Hazel Way Company Limited | Information & communication | 2020 |
| Hazel Whyte Ltd | Wholesale & retail | 2025 |
| Hazelwood Construction Ltd | Construction | 2015 |
| HB Safety Consultancy Ltd | Administrative & support | 2015 |
| HE Asian Station Ltd | Hospitality | 2023 |
| Headscarves by Ciara Limited | Other services | 2022 |
| Healthful Cultures Consulting Ltd | Health & social care | 2021 |
| Heatherlea Holdings Ltd | Financial services | 2025 |
| Heathtom Properties Limited | Real estate | 2001 |
| Hebe Barlow Limited | Wholesale & retail | 2025 |
| Heighten Felicity Ltd | Wholesale & retail | 2024 |
| Helenton Ltd | Wholesale & retail | 2024 |
| Helipower Hire Limited | Administrative & support | 2016 |
| Helipower Ltd | Transport & logistics | 2014 |
| Henderson Refrigeration Ltd | Manufacturing | 2023 |
| Heniellt Limited | Wholesale & retail | 2025 |
| HEO Mihye Ltd | Wholesale & retail | 2024 |
| Hera Services Ltd | Information & communication | 2023 |
| Herbie Frogg Limited | Manufacturing | 2025 |
| Herron Renewables Ltd | Energy | 2012 |
| Hetiwei Limited | Wholesale & retail | 2025 |
| Hexagon (NI) LLP | | 2014 |
| Hexalogic Ltd | Wholesale & retail | 2024 |
| Heyue Candy Limited | Wholesale & retail | 2025 |
| Hi-Flame Stoves Limited | Wholesale & retail | 2025 |
| Hibernia Finance Ltd | Professional & scientific | 2024 |
| Hibernia Medical Limited | Wholesale & retail | 2022 |
| High Horse Pizza Ltd | Hospitality | 2024 |
| Hill Understand Limited | Manufacturing | 2023 |
| Hillmont Developments Limited | Real estate | 2007 |
| Hilltex Farms Ltd | Agriculture & fishing | 2024 |
| Hillview Moneyreagh Management Company Limited | Households | 2016 |
| Hinchfields Management Company Limited | Households | 2026 |
| HJB Plant Hire Ltd | Construction | 2012 |
| HK Jiahang Technology Limited | Wholesale & retail | 2025 |
| Hmklean Ltd | Professional & scientific | 2018 |
| Hnsonz Limited | Wholesale & retail | 2025 |
| Hogg Sport Horses Ltd | Agriculture & fishing | 2019 |
| Holam Limited | Wholesale & retail | 2024 |
| Holistic Pet (NI) Limited | Professional & scientific | 2011 |
| Hollow Farm Shooting Grounds Limited | Arts & recreation | 2004 |
| Hollowen Ltd | Wholesale & retail | 2025 |
| Hollys Doggys Ltd | Other services | 2022 |
| Holroyd (NI) Limited | Information & communication | 2021 |
| Home Care Services (NI) Limited | Health & social care | 2008 |
| Home Kare & Co Limited | Wholesale & retail | 2019 |
| Home-Start Ards Comber and Peninsula Area | Other services | 2005 |
| Honesty Holdings Limited | Wholesale & retail | 2025 |
| Hongkong Ruike International Limited | Wholesale & retail | 2025 |
| Hongqin Kind Limited | Wholesale & retail | 2025 |
| Horizon Grove Enterprises Ltd | Wholesale & retail | 2024 |
| Hosail Limited | Wholesale & retail | 2024 |
| Hot Hatch Car Sales Ltd | Wholesale & retail | 2019 |
| Hotisut Limited | Wholesale & retail | 2025 |
| House Church Ltd | Other services | 2008 |
| House Coffee Enterprise Ltd | Other services | 2016 |
| House of Gregory Ltd | Real estate | 2024 |
| HQ Seng Limited | Wholesale & retail | 2025 |
| Huahuaguan Limited | Wholesale & retail | 2025 |
| Huangjunqun Limited | Wholesale & retail | 2025 |
| Huanglili Limited | Wholesale & retail | 2025 |
| Huangsing Limited | Wholesale & retail | 2025 |
| Huangyaoqiang Ltd | Wholesale & retail | 2025 |
| Huangyiwei Ltd | Wholesale & retail | 2024 |
| Huber Property Ltd | Real estate | 2019 |
| Hugh D. Mccullough & Sons Limited | Construction | 1979 |
| Huichao BOR Ltd | Wholesale & retail | 2024 |
| Huihuip Limited | Wholesale & retail | 2024 |
| Huizhe Limited | Wholesale & retail | 2024 |
| Hulijuan Ltd | Wholesale & retail | 2024 |
| Humphr LAN Limited | Wholesale & retail | 2024 |
| Hundred Acre Wood Playgroup Ltd | Education | 2003 |
| Hundred Sale Limited | Wholesale & retail | 2024 |
| Hunter Asset Investment Ltd | Professional & scientific | 2021 |
| Hunter BKS Ltd | Professional & scientific | 2021 |
| HY Trading NI Ltd | Wholesale & retail | 2023 |
| Hydrogas(N.I.) Ltd | Construction | 2021 |
| Hygge Shmily Ltd | Wholesale & retail | 2024 |
| Hzhiy Trade Ltd | Wholesale & retail | 2023 |
| I Walsh & SON Ltd | Administrative & support | 2025 |
| IAN Nelson Ltd | Wholesale & retail | 2025 |
| IAN Scutt T/A Scutt Investigations Limited | Administrative & support | 2017 |
| Ian's Training Solutions Limited | Education | 2011 |
| Igos Investments Limited | Real estate | 2026 |
| Igraphic Ltd | Professional & scientific | 2019 |
| Iljaperminovsde Limited | Wholesale & retail | 2024 |
| Illuminate Counselling LLP | | 2021 |
| Imacrederetail Ltd | Wholesale & retail | 2025 |
| Imperial House Consulting Ltd | Professional & scientific | 2021 |
| Inday Ltd | Hospitality | 2023 |
| Independent Car Hire Limited | Administrative & support | 1999 |
| Indie Events Ltd | Hospitality | 2018 |
| Indie Fude Ltd | Wholesale & retail | 2014 |
| Industrial Coatings Ireland Ltd | Wholesale & retail | 2014 |
| Industrial Laundry Machinery Ltd | Other services | 2019 |
| Inglepine Software Ltd | Information & communication | 1999 |