| G.R.E.G. Services Ltd | Transport & logistics | 2024 |
| G7B Services Ltd | Administrative & support | 2021 |
| GAE Delivery Ltd | Transport & logistics | 2018 |
| Galboola Limited | Construction | 1975 |
| Gapped Ltd | Extraterritorial | 2022 |
| Gapped Online Limited | Wholesale & retail | 2002 |
| Gareth’S Property Maintenance Ltd | Construction | 2024 |
| Gavantha Limited | Financial services | 2023 |
| GBE (Mill Street) Limited | Construction | 2019 |
| Gbenga Adeyemi Limited | Health & social care | 2020 |
| GDS GAS Services (M&E) Limited | Other services | 2018 |
| GE Pro-Sealants Limited | Construction | 2006 |
| Gearbox and Axle Centre Ltd | Wholesale & retail | 2024 |
| Geargo Limited | Transport & logistics | 2018 |
| Genesis Distribution Limited | Transport & logistics | 1997 |
| Genesis Storage Limited | Extraterritorial | 2004 |
| Genmed Commercial Services Limited | Wholesale & retail | 2019 |
| Genmed Group Limited | Financial services | 2020 |
| Genmed Holdings Limited | Professional & scientific | 2012 |
| Genmed Imaging Infrastructure and IT Limited | Professional & scientific | 2012 |
| Genmed Laboratory Services Limited | Professional & scientific | 2012 |
| Genmed Management Services Limited | Professional & scientific | 2012 |
| Genmed Surgical Facilities Limited | Professional & scientific | 2012 |
| Genmed.Me Limited | Financial services | 2007 |
| Geraint Roberts Ltd | Professional & scientific | 2023 |
| Gerald Francis Land Limited | Real estate | 2021 |
| GET Mortgages Group Limited | Financial services | 2023 |
| Gfams Consulting Limited | Information & communication | 2024 |
| Gggoalkeeping Ltd | Arts & recreation | 2026 |
| Gillard & Associates Limited | Information & communication | 2017 |
| Gillify Ltd | Wholesale & retail | 2025 |
| Ginger Exhibitions Limited | Construction | 2004 |
| Ginny Hospitality Limited | Hospitality | 2024 |
| Gintastic Ltd | Hospitality | 2021 |
| GIO Delivery Ltd | Transport & logistics | 2018 |
| Gitab Ltd | Professional & scientific | 2026 |
| Glanmor Developments Limited | Construction | 1981 |
| Glawio CYF | Professional & scientific | 2016 |
| Glenn Saunders Ltd | Wholesale & retail | 2019 |
| Glynn Properties Limited | Real estate | 2022 |
| Go Local Magazine and Print Ltd | Professional & scientific | 2018 |
| Gofarm Limited | Agriculture & fishing | 2008 |
| Gofigur Ltd | Administrative & support | 2022 |
| Goldcliff Transport Limited | Transport & logistics | 2006 |
| Golden Gate 888 Ltd | Hospitality | 2025 |
| Goodeinsight Limited | Extraterritorial | 2013 |
| Gooderham Holdings Limited | Financial services | 2020 |
| Goodes Fitness Limited | Arts & recreation | 2014 |
| Goodhemp Ltd. | Transport & logistics | 2018 |
| Gpmg Audit Limited | Professional & scientific | 2024 |
| Gpmg Limited | Professional & scientific | 2007 |
| Gpmg Xero Limited | Information & communication | 2024 |
| Grace's Beauty Vault Ltd | Other services | 2026 |
| Graig Farm Limited | Health & social care | 2022 |
| Graig Farm Properties Limited | Real estate | 2026 |
| Grange Mill Court Residents Company Limited | Administrative & support | 1992 |
| Grange Trade Car Sales Ltd | Other services | 2018 |
| Grants Insulation Solutions Limited | Manufacturing | 2025 |
| Great Golf Breaks Ltd | Administrative & support | 2026 |
| Greenline Landscapes S W Ltd | Administrative & support | 2009 |
| Greenmeadow Golf and Country Club Limited | Arts & recreation | 1978 |
| Greenways Property Rental Limited | Households | 2025 |
| Greenworks Tree Surgery Ltd | Administrative & support | 2023 |
| Greymed Rejuvenation Ltd | Other services | 2025 |
| Griffiths Private Wealth Consultants Ltd | Professional & scientific | 2019 |
| Groundrich Limited | Administrative & support | 2015 |
| Grove One Capital Ltd | Real estate | 2025 |
| Groves GAS Ltd | Construction | 2014 |
| GS Electrical (UK) Limited | Construction | 2014 |
| GS Football Elite Ltd | Arts & recreation | 2025 |
| GSF Install Ltd | Manufacturing | 2019 |
| GUS Periscopes Limited | Manufacturing | 2018 |
| Gusto GEN Ltd | Manufacturing | 2017 |
| GW Garages Ltd | Wholesale & retail | 2023 |
| Gwasg PIA Cyfyngedig | Information & communication | 1990 |
| Gwasg PIA EOT Cyfyngedig | Professional & scientific | 2024 |
| Gwent Aluminium and Upvc Products Limited | Extraterritorial | 2011 |
| Gwent Engineering Limited | Construction | 2013 |
| Gwent GAS Limited | Construction | 2021 |
| Gwent Snooker Centres Limited | Arts & recreation | 1982 |
| GWR Waste Removals Ltd | Water & waste | 2026 |
| Gymatics Limited | Manufacturing | 2024 |
| H Johnson Roofing & Guttering Ltd | Construction | 2025 |
| H R Project Management Limited | Administrative & support | 1999 |
| H&C TV Limited | Information & communication | 2010 |
| H.L.T Holdings Ltd | Financial services | 2024 |
| H2A Holdings Ltd. | Financial services | 2022 |
| H2A Online Ltd | Financial services | 2017 |
| Hackwood Fabricated Solutions Ltd | Manufacturing | 2014 |
| Hadway Developments Ltd | Construction | 2022 |
| Hall's, Hooves and Hounds Ltd | Agriculture & fishing | 2025 |
| Hanbury Care Ltd | Health & social care | 2020 |
| Hanfield Holdings Limited | Financial services | 2020 |
| Happy Sexy Health Limited | Professional & scientific | 2022 |
| Happy Thai Catering Ltd | Hospitality | 2024 |
| Harris Group Investments Limited | Financial services | 2025 |
| Harrison & Osborne Limited | Administrative & support | 2007 |
| Harvey 4 Homes Ltd | Real estate | 2021 |
| Hathway Holdings Ltd | Financial services | 2020 |
| Haus of Apps Limited | Administrative & support | 2024 |