| G&T Windows & Doors Ltd | Construction | 2024 |
| G'S Burgers Ltd | Hospitality | 2025 |
| G.K.R. Maintenance & Building Co. Limited | Construction | 1998 |
| G4 Sales Management Limited | Wholesale & retail | 2016 |
| Gaea Group Ltd | Wholesale & retail | 2019 |
| Gaia Crafted Landscapes Ltd | Administrative & support | 2025 |
| Galileo Transport Ltd | Transport & logistics | 2023 |
| GAP Architectural & Engineering Design Services Limited | Professional & scientific | 2003 |
| Gareth Lewis Properties Ltd | Real estate | 2024 |
| Garran Lockers Limited | Manufacturing | 1997 |
| Garth Farm Contractors Plant Hire Limited | Administrative & support | 2009 |
| Garth Investment Properties Limited | Real estate | 2013 |
| Gary Lynch Ltd | Information & communication | 2023 |
| GAS Gold Limited | Construction | 2019 |
| Gasflair Wales Limited | Construction | 2003 |
| Gatenbys Independent Financial Advisers Ltd | Financial services | 2008 |
| Gavel Auctioneers Limited | Professional & scientific | 2012 |
| Gavel Auctions Limited | Wholesale & retail | 2020 |
| Gavel Holdings Limited | Financial services | 2015 |
| GB Vehicle Contracts Limited | Administrative & support | 2020 |
| GDS South Wales Limited | Construction | 2003 |
| GEF Tech Ltd | Manufacturing | 2026 |
| Geff Logistics Ltd | Transport & logistics | 2025 |
| GET Blinds Online Ltd | Wholesale & retail | 2020 |
| GF Europe Limited | Manufacturing | 2003 |
| GGP Property Management Limited | Administrative & support | 2013 |
| GHD Civils Limited | Construction | 2022 |
| GHD Property Ltd | Extraterritorial | 2025 |
| GHJ Investments Ltd | Real estate | 2024 |
| Gifts With Heart Limited | Wholesale & retail | 2019 |
| Gillespie Estates Ltd | Real estate | 2020 |
| GIN Lizzy Ltd | Wholesale & retail | 2022 |
| Gina's Goals Ltd | Hospitality | 2022 |
| GKM Group Limited | Administrative & support | 2016 |
| GL Electrical Installations Ltd | Construction | 2026 |
| GL Fortune Limited | Hospitality | 2021 |
| Glad People Limited | Information & communication | 2017 |
| Glasseal Architectural Limited | Manufacturing | 2015 |
| Glen Real Estate Limited | Real estate | 2021 |
| Glenmay (Services) Limited | Real estate | 2012 |
| Glenside Commercials Limited | Wholesale & retail | 1975 |
| Glew Marketing Ltd | Professional & scientific | 2016 |
| Global Business Mentoring Ltd. | Professional & scientific | 2024 |
| Global Solutions Network Ltd | Wholesale & retail | 2014 |
| Glowluxlights Ltd | Wholesale & retail | 2025 |
| Gndsm Limited | Professional & scientific | 2022 |
| Go 4 IT Activities Wales Limited | Arts & recreation | 2011 |
| Goconnect Ltd | Other services | 2013 |
| Godwin Contracting Services Limited | Construction | 2004 |
| Golf in Wales Limited | Arts & recreation | 2002 |
| Goode Strength Ltd | Arts & recreation | 2025 |
| Graham Bradley Limited | Other services | 2012 |
| Graig Fawr Livery Limited | Agriculture & fishing | 2021 |
| Grange Industries Group Limited | Construction | 2016 |
| Gravloc UK Limited | Manufacturing | 2007 |
| Grcleaning Limited | Administrative & support | 2018 |
| Great Wall Chinese Ltd | Hospitality | 2026 |
| Green Bison Limited | Financial services | 2002 |
| Green Bison Partnerships Limited | Professional & scientific | 2018 |
| Green Core Consult Limited | Professional & scientific | 2015 |
| Green Orbit Ltd | Professional & scientific | 2023 |
| Green Property Solutions Limited | Real estate | 2009 |
| Green World Electrical and Renewable Limited | Construction | 2020 |
| Greens Recycling (Wales) Limited | Water & waste | 2013 |
| Greenwood Services Ltd | Real estate | 2015 |
| Gregory Davies Wealth Management Ltd | Professional & scientific | 2019 |
| Grey Services 56 Ltd | Information & communication | 2022 |
| GSD Media Group Ltd | Information & communication | 2021 |
| GT Heating Solutionz Ltd | Construction | 2018 |
| Guard Tech Limited | Information & communication | 2015 |
| Gutterguzzler Ltd | Administrative & support | 2025 |
| Gwalia Cyfyngedig | Wholesale & retail | 2020 |
| Gwent Properties Ltd | Real estate | 2025 |
| Gwindy 2012 Limited | Professional & scientific | 2012 |
| Gwragedd Annwn Ltd | Education | 2024 |
| H & I Retail Limited | Wholesale & retail | 2024 |
| H M Morgan Engineers Limited | Manufacturing | 1994 |
| H&C Consultant Ltd | Health & social care | 2025 |
| H.L.P Group Holdings Ltd | Financial services | 2025 |
| H.L.P Property Group Ltd | Financial services | 2025 |
| H.L.P. Tube Formers Limited | Manufacturing | 1965 |
| H2O Fire Solutions Limited | Public administration | 2022 |
| Hadu Group Limited | Financial services | 2025 |
| Hallventure Limited | Construction | 1982 |
| Halo Product Design Limited | Manufacturing | 2010 |
| Halo Therapeutics Ltd | Professional & scientific | 2020 |
| Hammer Scaffolding Ltd | Construction | 2020 |
| Hampson Properties Ltd | Hospitality | 2020 |
| Handicare Patient Handling Limited | Administrative & support | 2020 |
| Handy Learners Ltd | Information & communication | 2021 |
| Hangry Studio Ltd | Professional & scientific | 2024 |
| Hanumant Traders Ltd | Wholesale & retail | 2023 |
| Haraldo Limited | Hospitality | 2007 |
| Harlex Group Ltd | Financial services | 2020 |
| Harmoni Homes Limited | Construction | 2017 |
| Harmony Homestead Ltd | Other services | 2025 |
| Harrap Park Management Company Limited | Households | 2023 |
| Harris Financial Consulting Ltd | Financial services | 2019 |
| Hatch Consultancy Limited | Professional & scientific | 2026 |
| Haughton Couriers Ltd | Transport & logistics | 2025 |