| General Waters (U.K.) Limited | Water & waste | 1991 |
| Genius Compliance Solutions Ltd | Financial services | 2015 |
| Genus Consulting Ltd | Real estate | 2020 |
| Gerwyn Price Merchandise Limited | Wholesale & retail | 2025 |
| Geysir Yurts Ltd | Professional & scientific | 2022 |
| Gfix Classic Cars Ltd | Wholesale & retail | 2020 |
| GHR Developments Limited | Construction | 2015 |
| Gilgit Shilajit Ltd | Wholesale & retail | 2023 |
| Glass Planet Limited | Manufacturing | 2017 |
| Gldn Property Ltd | Construction | 2023 |
| Gldn Sourcing Ltd | Real estate | 2023 |
| Glendale Property Developments (Wales) Limited | Real estate | 2006 |
| Glenn Willis Ltd | Construction | 2005 |
| Gloss N Glow Beauty Studio Limited | Other services | 2023 |
| Glyn's Repair Services Limited | Wholesale & retail | 2014 |
| Gm-It Services Ltd | Information & communication | 2018 |
| Goldbull Ltd | Transport & logistics | 2019 |
| Golden Floor Restoration Ltd | Construction | 2025 |
| Golden Sun Fish and Chips Limited | Hospitality | 2025 |
| GP LIN Ltd | Hospitality | 2018 |
| Graham Davies Family Wealth Ltd | Professional & scientific | 2022 |
| Graigwen Cafe Ltd | Hospitality | 2017 |
| Grand Developments Ltd | Construction | 2007 |
| Grankoak Developments Ltd | Construction | 2026 |
| Green and Ground Limited | Hospitality | 2026 |
| Green Bay Services Ltd | Administrative & support | 2022 |
| Greenfields Nursery Blackwood Limited | Education | 2024 |
| Greenmeadow Investments Ltd | Real estate | 2021 |
| Griffin Security Limited | Administrative & support | 2022 |
| Grifflec Electrical Ltd | Construction | 2026 |
| Grimstead Hospitality Limited | Hospitality | 2025 |
| GRJ Property Limited | Real estate | 2025 |
| Groundwork Caerphilly | Administrative & support | 1990 |
| Groundwork Wales | Administrative & support | 1998 |
| Grownz Limited | Hospitality | 2022 |
| GSD Business Consultancy Ltd | Professional & scientific | 2020 |
| Gwent Detailing Supplies Ltd | Wholesale & retail | 2025 |
| Gwent Hotels Limited | Hospitality | 2023 |
| Gwent Mobile Tyres Ltd | Wholesale & retail | 2018 |
| Gwent Pest Control Solutions and Pest Management Ltd | Professional & scientific | 2026 |
| H C Capel (Holdings) Limited | Real estate | 2015 |
| Haines and Powell Investments Limited | Real estate | 2021 |
| Hair by Sherie Limited | Other services | 2026 |
| Hair by Unique Ltd | Other services | 2021 |
| Halfway House Gwent Limited | Hospitality | 2019 |
| Hammer Core Ltd | Construction | 2026 |
| Happy Bytes Ltd | Information & communication | 2022 |
| Happy Learners Limited | Wholesale & retail | 2019 |
| Harriman Property Ltd | Real estate | 2020 |
| Harris Coaches (Pengam) Limited | Transport & logistics | 1974 |
| Haulfryn Developments Ltd | Construction | 2016 |
| Hawkesford Construction Ltd | Construction | 2015 |
| Hayesgate Oakmont Limited | Transport & logistics | 2022 |
| Heatsafe Limited | Construction | 2026 |
| Heatzonesolutions Limited | Construction | 2019 |
| Hendre Consultants Ltd | Construction | 2021 |
| Herons Homes Ltd | Real estate | 2024 |
| HG Corporation Ltd | Financial services | 2025 |
| Highgrade Recruitment Limited | Administrative & support | 2011 |
| Hill View Care Home Limited | Health & social care | 2016 |
| Hillside Accounting & Management Solutions Ltd | Professional & scientific | 2017 |
| Hire Design Limited | Information & communication | 2010 |
| Hisberts Inc Ltd | Financial services | 2026 |
| HJ Residential Building Surveys Ltd | Construction | 2022 |
| Home From Home Support Ltd | Administrative & support | 2022 |
| Homemade by ME Limited | Hospitality | 2012 |
| Honey Grove Estates Ltd | Real estate | 2024 |
| Honey Grove Sales and Lettings Ltd | Real estate | 2025 |
| Honey Rose Limited | Wholesale & retail | 2024 |
| Hopely Ltd | Transport & logistics | 2016 |
| Hopes END Ltd | Hospitality | 2022 |
| Hotel Narrowboats Limited | Transport & logistics | 2013 |
| Howls Independent Financial Advice Ltd | Financial services | 2018 |
| Howses Limited | Construction | 2002 |
| Hrhk Holdings Limited | Hospitality | 2025 |
| HT Group Services Ltd | Other services | 2015 |
| Hubu Media Ltd | Information & communication | 2021 |
| Hubu Properties Ltd | Real estate | 2021 |
| Huish Properties Limited | Real estate | 2021 |
| Hunter Sport Homes Ltd | Manufacturing | 2017 |
| Hurley and Davies Holdings Limited | Financial services | 2021 |
| Hurley and Davies Limited | Professional & scientific | 2002 |
| HV Holdings (Blackwood) Ltd | Financial services | 2025 |
| HV Solutions Ltd | Manufacturing | 2022 |
| Hwga Life Ltd | Wholesale & retail | 2021 |
| I Rose Tutoring Services Ltd | Education | 2020 |
| I-Smiles.Com Ltd. | Health & social care | 2011 |
| I.G. Doors Limited | Manufacturing | 2003 |
| Ideal Auto Enrolment Solutions Limited | Administrative & support | 2015 |
| IG Doors (Scotland) Limited | Manufacturing | 2002 |
| IH Construction Training Limited | Construction | 2023 |
| IMP Pharmaceutical Services Ltd | Professional & scientific | 2015 |
| Innovate Engineering Solutions Limited | Professional & scientific | 2024 |
| Insight Applied Ltd | Information & communication | 2026 |
| Insight Contracting Ltd | Construction | 2020 |
| Interlink Peptides Ltd | Wholesale & retail | 2026 |
| Intuitive Pharma Solutions Ltd | Professional & scientific | 2022 |
| Isabel Louisa Ltd | Manufacturing | 2025 |
| Islwyn Hospitality Limited | Hospitality | 2023 |
| Isocount Laboratory Services Limited | Manufacturing | 2019 |