| Gwysaney Sporting Club Limited | Arts & recreation | 2021 |
| H & P OFF Licence Ltd | Wholesale & retail | 2021 |
| H G Eastwood Building Services Ltd | Construction | 2022 |
| Habitronix Ltd | Manufacturing | 2025 |
| Hadyn Ltd | Hospitality | 2025 |
| Hafod Brewing Company Ltd | Manufacturing | 2011 |
| Hafod Heating Ltd | Construction | 2021 |
| Hafodunos Farms Limited | Agriculture & fishing | 1977 |
| Halkyn Consulting Ltd | Information & communication | 2010 |
| Halsted Projects Ltd | Information & communication | 2006 |
| Hand Car Wash Mold Ltd | Administrative & support | 2023 |
| Hanks Marine Services Limited | Transport & logistics | 2019 |
| Hanmore Property LLP | | 2016 |
| HAPPYGARDENMOLD87 Ltd | Hospitality | 2024 |
| Harada Homes Ltd | Construction | 2020 |
| Harbour HQ Ltd | Professional & scientific | 2025 |
| Harrison Design Development Limited | Professional & scientific | 2007 |
| Harry Barber 29 Ltd | Other services | 2026 |
| Harvey Parr Limited | Professional & scientific | 2003 |
| Harvie's Limited | Manufacturing | 2002 |
| Hatsch Trading Ltd | Financial services | 2014 |
| Haul AR Fryn CYF. | Real estate | 2025 |
| Hawarden Sporting Limited | Arts & recreation | 2021 |
| Hawthorns Property Investments Limited | Real estate | 2025 |
| HD GAS & Plumbing Ltd | Construction | 2024 |
| Heaven Real Estate Ltd | Real estate | 2025 |
| Heliomic Energy Limited | Professional & scientific | 2025 |
| Helix and Felix Limited | Professional & scientific | 2015 |
| Helyg Developments Limited | Construction | 2024 |
| Helyg Homes Limited | Construction | 2020 |
| Hemmo Holdings Limited | Financial services | 2024 |
| Heron Construction Ltd | Real estate | 2022 |
| Herons Lake Retreat Ltd | Hospitality | 2012 |
| Herons Lake Retreat NO10 Ltd | Hospitality | 2020 |
| Herons Lake Retreat NO2 Ltd | Real estate | 2012 |
| Herons Lake Retreat NO5 Ltd | Hospitality | 2020 |
| HGR Limited | Extraterritorial | 2015 |
| Hicks Accountancy Limited | Real estate | 2015 |
| High Five CLO Ltd | Wholesale & retail | 2026 |
| Highfield Holiday Lets Limited | Hospitality | 2014 |
| Highgate Consultancy Services Limited | Professional & scientific | 2023 |
| Hill and Roberts Limited | Professional & scientific | 2016 |
| Hillvern Properties Limited | Real estate | 2016 |
| Hiraeth Productions CYF | Information & communication | 2024 |
| HK & GK Jones (Joinery Roofing & Building Contractors) Limited | Construction | 2008 |
| HM Agri Ltd | Professional & scientific | 2025 |
| Holts Holdings Limited | Construction | 1999 |
| Holts Homes Limited | Construction | 1999 |
| Holts Orangeries & Conservatories Ltd | Construction | 2012 |
| Home Serenity Builders Ltd | Construction | 2025 |
| Home-Start Flintshire | Other services | 2005 |
| Homegrown Hollingsworth Ltd | Wholesale & retail | 2019 |
| Hospitality IT Solutions Limited | Information & communication | 2018 |
| Host Island Limited | Real estate | 2021 |
| Hot Dice Games Ltd | Wholesale & retail | 2024 |
| House of Beauty (Mold) Ltd | Other services | 2017 |
| Huelp Ltd | Information & communication | 2020 |
| Hugo Watts Consulting Ltd | Manufacturing | 2014 |
| Humphreys & Tarran Ltd | Construction | 2014 |
| HUW Jones Contracting Limited | Construction | 2025 |
| HVF Heating & Plumbing Ltd | Construction | 2022 |
| Hwbnaw Limited | Information & communication | 2018 |
| Hyfryd Mechanical Services Ltd | Professional & scientific | 2024 |
| I & S Major Limited | Wholesale & retail | 2017 |
| I.W.A.B.S.S. Limited | Professional & scientific | 2011 |
| IAN Wright Consulting Limited | Information & communication | 2014 |
| Iandsland Limited | Real estate | 2024 |
| ICG Agents Unlimited | Financial services | 2024 |
| ICU Security Ltd | Administrative & support | 2023 |
| Idevelop Limited | Information & communication | 2006 |
| IDH Group Limited | Information & communication | 2024 |
| IDR Business Services & Solutions Ltd | Professional & scientific | 2025 |
| IJH Enterprises Limited | Information & communication | 2011 |
| IK One Design Limited | Construction | 2026 |
| Illume 360 Strategies Ltd | Professional & scientific | 2024 |
| Imagination Works Limited | Administrative & support | 2017 |
| Impact Metering Solutions Limited | Wholesale & retail | 2020 |
| Independent Funeral Services (NW) Ltd | Other services | 2016 |
| Independent Funeral Services Limited | Other services | 2002 |
| Indian Lounge Nannerch Ltd | Hospitality | 2017 |
| Indian Restaurants T/A Indian Lounge Ltd | Hospitality | 2020 |
| Industrial Mixers Ltd | Wholesale & retail | 2025 |
| Industry Advancement Limited | Construction | 2013 |
| Influencex Ltd | Professional & scientific | 2025 |
| Infunity Ltd | Hospitality | 2016 |
| Innovate Adventure Ltd | Administrative & support | 2025 |
| Insights Development Limited | Professional & scientific | 2025 |
| Integrated Lean Solutions Limited | Professional & scientific | 2010 |
| Interalia Marketing Ltd | Professional & scientific | 2019 |
| Intermediate Speciality Chemicals Limited | Professional & scientific | 1999 |
| Iprime Indexing Ltd | Information & communication | 2019 |
| Irish Dragon Holdings Limited | Financial services | 2025 |
| Irish Dragon Property Holdings Limited | Financial services | 2026 |
| Isabelle Rose Creatives Limited | Professional & scientific | 2023 |
| Isabelle Rose Limited | Professional & scientific | 2023 |
| Isew Digital UK Ltd | Manufacturing | 2025 |
| Isis Bankruptcy Services Limited | Professional & scientific | 2007 |
| IT Accounts Support Limited | Information & communication | 2013 |
| IT Extra Ltd | Information & communication | 2023 |
| Itas Solutions Limited | Information & communication | 2015 |