| Griffith Site Engineering Services Limited | Professional & scientific | 2015 |
| Grit Media Ltd | Professional & scientific | 2025 |
| Group & Event Travel Ltd | Administrative & support | 2025 |
| GRS Eco Ltd | Other services | 2022 |
| GS Geoscience Limited | Professional & scientific | 2008 |
| GS33 Ltd | Health & social care | 2023 |
| Gstsemengineering Limited | Information & communication | 2013 |
| Gunzfactor Ltd | Information & communication | 2026 |
| GVG Commercials Limited | Real estate | 2025 |
| Gvgproperties Limited | Hospitality | 2022 |
| Gwelfor Ltd | Financial services | 2014 |
| GWP Electrical Ltd | Construction | 2014 |
| H & C Self Storage Ltd | Transport & logistics | 2022 |
| H & R Jones CYF | Agriculture & fishing | 2022 |
| H Squared Holdings Limited | Financial services | 2016 |
| H Whittaker & SON Cymru Limited | Administrative & support | 2002 |
| Hafal | Health & social care | 2002 |
| Hafan Y Coed CIC | Education | 2026 |
| Hafod-Y-Bryn Cattery Limited | Agriculture & fishing | 2014 |
| Hafod-Y-Bryn Kennels Limited | Agriculture & fishing | 2013 |
| Hair Hive Academy Limited | Wholesale & retail | 2026 |
| Halcyon Solutions NW Ltd | Wholesale & retail | 2021 |
| Hallview Leisure Ltd | Arts & recreation | 2021 |
| Hammond & Hunter Limited | Hospitality | 2017 |
| Hampson Solutions Ltd | Administrative & support | 2002 |
| Hanbec Limited | Wholesale & retail | 2013 |
| Hanson Property Managment Limited | Real estate | 2021 |
| Harker Catering Limited | Hospitality | 2025 |
| Harmony Wedding Hair Ltd | Other services | 2024 |
| Harvey Mark Property Lettings & Management Ltd | Hospitality | 2024 |
| Haus Coffee Limited | Hospitality | 2025 |
| Haven of Light CIC | Professional & scientific | 2017 |
| Hawcourt Limited | Professional & scientific | 2022 |
| Heenan Homes Ltd | Real estate | 2022 |
| Heritage Living Limited | Real estate | 2023 |
| Herleys Homes Ltd | Real estate | 2026 |
| Hesketh Harbridge Limited | Construction | 2025 |
| Heywood and Heywood Limited | Professional & scientific | 2017 |
| HG Marine Limited | Manufacturing | 2024 |
| High Court Enforcement Group Limited | Professional & scientific | 2002 |
| Hiraeth Pictures Limited | Information & communication | 2019 |
| HK Tiling & Bathrooms Ltd | Construction | 2026 |
| Holiday Homes (NW) Limited | Hospitality | 2021 |
| Holiday Property Management (Conwy) Ltd | Hospitality | 2019 |
| Hormacks Limited | Transport & logistics | 2020 |
| Hornell Tree Services Limited | Administrative & support | 2016 |
| House of the Vivienne CIC | Health & social care | 2025 |
| Hovezy Carpentry Limited | Manufacturing | 2025 |
| Howitt Wealth Management Limited | Financial services | 2012 |
| HPM Services (Conwy) Ltd | Hospitality | 2026 |
| Human Intelligence Learning Ltd | Education | 2025 |
| Human Kind : We'Re Both Limited | Health & social care | 2024 |
| Hybridxuk Ltd | Arts & recreation | 2024 |
| Hydrohire Limited | Administrative & support | 2008 |
| Hyperport Ltd | Information & communication | 2024 |
| HÂF Homes Ltd | Real estate | 2022 |
| I C & J Investments Limited | Real estate | 2024 |
| I.O. Lowe Ltd | Administrative & support | 2013 |
| IAG Investments Ltd | Hospitality | 2003 |
| IAN Roberts Management Consultancy Ltd | Professional & scientific | 2017 |
| Iclg Ltd | Wholesale & retail | 2014 |
| Ignite Joinery Ltd | Construction | 2023 |
| Imagine Gins Limited | Wholesale & retail | 2019 |
| Imperial Developers and Management Limited | Construction | 2007 |
| Imugi Ltd | Extraterritorial | 2016 |
| Indomitable Studios Ltd | Information & communication | 2026 |
| Insidr Limited | Information & communication | 2023 |
| Inspired Assisted Living Ltd | Health & social care | 2010 |
| Inspired Homes Network Ltd | Other services | 2012 |
| Intimately YOU Ltd | Health & social care | 2023 |
| ION Construction Limited | Construction | 2005 |
| Itech Global Solutions Ltd | Information & communication | 2018 |
| Iteration One Ltd | Information & communication | 2014 |
| Ivendi Limited | Information & communication | 2009 |
| J Cheung's Property Ltd | Real estate | 2024 |
| J.K.Modernbuild Ltd | Construction | 2023 |
| J.W.D Wind Contracting Services Ltd. | Professional & scientific | 2025 |
| Jack Andreou Creative Ltd | Other services | 2023 |
| Jackie's Limited | Hospitality | 2024 |
| Jamelis Design Ltd | Wholesale & retail | 2022 |
| Jamie Seager Scaffolding Services Limited | Construction | 2011 |
| Jazlettings Ltd | Real estate | 2019 |
| Jconline Limited | Wholesale & retail | 2022 |
| Jcsales Limited | Wholesale & retail | 2018 |
| JD (North Wales) Ltd | Hospitality | 2023 |
| JD Refrigeration Cymru Limited | Other services | 2002 |
| JD Windtech Ltd | Professional & scientific | 2026 |
| JDC Plant & Engineering Ltd | Manufacturing | 2014 |
| JDE James Davies Earthworks Ltd | Construction | 2019 |
| JDS Consulting (NW) Limited | Construction | 2022 |
| Jemtrak Limited | Transport & logistics | 2009 |
| Jennings Building & Civil Engineering Limited | Construction | 1984 |
| JH Leisure Ltd | Hospitality | 2024 |
| Jimmy Choo Choo Ltd | Wholesale & retail | 2014 |
| Jixiang CW Limited | Hospitality | 2026 |
| JJC Construction Projects Ltd | Construction | 2025 |
| JJD Property Limited | Real estate | 2024 |
| JJS Consultants Ltd | Administrative & support | 2019 |
| JLE Plumbing Ltd | Construction | 2021 |
| Jloew Limited | Transport & logistics | 2025 |