| Havana Trading NO.8 Limited | Extraterritorial | 2017 |
| Havana Trading NO.9 Limited | Extraterritorial | 2017 |
| Haven (PNH) Limited - the | Health & social care | 2005 |
| Haven Rock Properties Limited | Real estate | 2025 |
| Havenglow Limited | Wholesale & retail | 2025 |
| Havz Limited | Wholesale & retail | 2021 |
| Hawk Hurst Construction Limited | Construction | 2024 |
| Hawk Imaging Ltd | Health & social care | 2015 |
| Hawkins Services N.I. Ltd | Construction | 2025 |
| Hawthorn Belfast Limited | Professional & scientific | 2025 |
| Hawthorn Designs NI Limited | Professional & scientific | 2016 |
| Hawthorn Mews Management Company Limited | Real estate | 2012 |
| Hawthorn Office Park Management Company Limited | Households | 2003 |
| Hawthorn Theatre Productions Limited | Arts & recreation | 2026 |
| Hawthornden Building Consultants Ltd | Professional & scientific | 2023 |
| Hawthornden Lodge Limited | Extraterritorial | 1984 |
| Hawthorne Court Ltd | Households | 2019 |
| Haybury Business Coaching Limited | Professional & scientific | 2004 |
| Hayhill Trading Limited | Real estate | 2020 |
| Hazeldene Court Limited | Real estate | 1999 |
| Hazelhaw Properties Limited | Administrative & support | 2002 |
| Hazelton Consulting Limited | Professional & scientific | 2024 |
| Hazelwood Apartments Management Limited | Households | 2002 |
| Hazelwood Fishery Ltd | Hospitality | 2026 |
| HB Building Property Services Limited | Construction | 2013 |
| HB Electronics Limited | Wholesale & retail | 2023 |
| HB Measure & Mentor Ltd | Professional & scientific | 2025 |
| Hbzkkq Ltd | Wholesale & retail | 2024 |
| HC Belmont Ltd | Arts & recreation | 2026 |
| HC Malone Ltd | Arts & recreation | 2025 |
| HCA Audit Ltd | Professional & scientific | 2022 |
| HCA Business Recovery Limited | Professional & scientific | 2016 |
| HCA Chartered Accountants Ltd | Professional & scientific | 2013 |
| HCA Corporate Finance Limited | Professional & scientific | 2016 |
| HCA Holdings Limited | Financial services | 2019 |
| Hcamba Limited | Financial services | 2022 |
| HCC (Belfast) Ltd | Wholesale & retail | 2016 |
| Hced Ltd | Information & communication | 2018 |
| HCI Realisations 1 Limited | Construction | 2011 |
| HCJ Solutions Ltd | Professional & scientific | 2022 |
| HD Decor Limited | Construction | 2024 |
| HDI Capital Limited | Real estate | 2023 |
| HDP NI Limited | Professional & scientific | 2017 |
| HE SHE EAT Dunmurry Ltd | Hospitality | 2025 |
| Head Studios Ltd | Professional & scientific | 2023 |
| Headcoach App Ltd | Education | 2020 |
| Heal and Thrive CIC | Education | 2025 |
| Heal Medical Ltd | Health & social care | 2024 |
| Healing Heat Ltd | Other services | 2020 |
| Healing Through Remembering | Health & social care | 2003 |
| Healing With Gabe Ltd | Health & social care | 2024 |
| Health & Beauty Uniforms (2015) Ltd | Manufacturing | 2015 |
| Health and Safety Consulting Limited | Public administration | 2019 |
| Health Chan Limited | Wholesale & retail | 2023 |
| Health Excellence Group Limited | Administrative & support | 2024 |
| Health Innovation Research Alliance | Other services | 2019 |
| Health MAP UN Limited | Information & communication | 2025 |
| Health One Group Limited | Administrative & support | 2022 |
| Health One Homecare Limited | Health & social care | 2025 |
| Health Sector Talent UK Limited | Administrative & support | 2023 |
| Healthcare Technologies Limited | Health & social care | 2016 |
| Healthgoods Alliance Ltd | Wholesale & retail | 2025 |
| Healthodontic Ltd | Health & social care | 2015 |
| Healthsourceireland Ltd | Wholesale & retail | 2020 |
| Healthwise Foods Ltd | Manufacturing | 2025 |
| Healthy Flower Limited | Wholesale & retail | 2023 |
| Healthy Food Catering Ltd | Hospitality | 2017 |
| Healthy Living Centres Alliance Ltd | Health & social care | 2018 |
| Healthy Mind Coaching Ltd | Health & social care | 2014 |
| Healthywealthy VEG & Vegan Ltd | Wholesale & retail | 2025 |
| Healy Brothers Funeral Directors Limited | Other services | 2007 |
| Heanen Stanfield & Mckee (Lisburn) Ltd | Professional & scientific | 2020 |
| Heaney Heating Limited | Construction | 2011 |
| Heaney Heating Plumbing Limited | Construction | 2015 |
| Heaney Heating Services (NI) Ltd | Construction | 2011 |
| Hear Clearni Ltd | Wholesale & retail | 2020 |
| Hear My Voice Films Ltd | Information & communication | 2017 |
| Heart Health With DR COX Limited | Health & social care | 2026 |
| Heart Rhythm International Limited | Information & communication | 2024 |
| Heartsine Technologies Limited | Manufacturing | 1998 |
| Heat Generation UK Ltd. | Construction | 2025 |
| Heat Wave Tanning (NI) Ltd | Other services | 2015 |
| Heat, Energy and Associated Technology Limited | Construction | 1982 |
| Heatcare (NI) Limited | Manufacturing | 2007 |
| Heating Solutions (2018) Ltd | Construction | 2018 |
| Heatons (N.I.) Limited | Wholesale & retail | 1999 |
| Hector Mcdonnell Ltd | Arts & recreation | 2010 |
| Hedgelea Park One Property Management Company Limited | Households | 2000 |
| Hedonic Asset Management Ltd | Households | 2024 |
| Heeva JD Limited | Wholesale & retail | 2025 |
| Hefan Technology Limited | Wholesale & retail | 2025 |
| Heffron Contracts Limited | Administrative & support | 2002 |
| Hegan & Co. Ltd | Real estate | 2011 |
| Hegaro Ltd | Real estate | 2023 |
| Hegarty Ortho Limited | Health & social care | 2024 |
| Heilala Vanilla Ltd | Wholesale & retail | 2024 |
| Heim Medics Limited | Health & social care | 2015 |
| Helen Burns Solicitors Ltd. | Professional & scientific | 2013 |
| Helen Healthcare Agency Ltd | Public administration | 2021 |
| Helen Sloan Photography Ltd | Information & communication | 2013 |