| Final Key Ltd | Education | 2019 |
| Finance Simplified Ltd | Financial services | 2015 |
| Financial Excel Limited | Professional & scientific | 2017 |
| Finite International Logistics Ltd | Transport & logistics | 2012 |
| Finplicity Limited | Information & communication | 2021 |
| Fire Curtain Corporation Limited | Extraterritorial | 2009 |
| Fitcentr Limited | Information & communication | 2022 |
| Fited Limited | Education | 2011 |
| Fitter Body Ladies (Wales) Limited | Arts & recreation | 2020 |
| Fitter Body Ladies Birchgrove Ltd | Arts & recreation | 2026 |
| Fitter Body Ladies Cardiff Central Ltd | Arts & recreation | 2023 |
| Fitter Body Ladies Sketty Ltd | Arts & recreation | 2020 |
| Fixtures Fittings Ltd | Financial services | 2025 |
| Fleeting Meeting Limited | Information & communication | 2003 |
| Flip Flop Properties Ltd | Real estate | 2021 |
| Flippin’ Heck Ltd | Construction | 2026 |
| Flong Ltd | Information & communication | 1992 |
| Flowerbe Limited | Other services | 2016 |
| Focus Wealth Financial Planning Ltd | Professional & scientific | 2025 |
| Focused Advice Limited | Professional & scientific | 2025 |
| Foji Barbers Ltd | Other services | 2024 |
| Folio Typographics Ltd | Professional & scientific | 2004 |
| FOR Goodness Taste Limited | Hospitality | 2022 |
| Four Lines Consultancy Limited | Other services | 2008 |
| Fourways News Distribution Ltd | Wholesale & retail | 2023 |
| FOX Fitzgerald Brands Limited | Wholesale & retail | 2019 |
| FOX Fitzgerald Limited | Administrative & support | 2010 |
| FOX Fitzgerald Whisky Trading Company Limited | Wholesale & retail | 2013 |
| Fox's DEN Limited | Professional & scientific | 2012 |
| Foxbow Limited | Information & communication | 2020 |
| Frankie's Construction Ltd | Construction | 2026 |
| Fravacom Limited | Wholesale & retail | 2018 |
| Freemantle Marine Services Ltd | Manufacturing | 2023 |
| French Property Investments Ltd | Real estate | 2018 |
| Frobenius Limited | Information & communication | 2012 |
| Funding Futures Ltd. | Professional & scientific | 2023 |
| Funding Matters Limited | Administrative & support | 2003 |
| Future Cctv and Security Systems Limited | Administrative & support | 2016 |
| FVO Medcare Services Ltd | Administrative & support | 2019 |
| G & M Shaw Property Holdings Limited | Real estate | 2025 |
| G & S Projects Ltd | Administrative & support | 2006 |
| G&M Lifting & Moving Ltd | Transport & logistics | 2020 |
| G.H.Moreton Limited | Wholesale & retail | 1965 |
| G.W.E. Developments Limited | Administrative & support | 2012 |
| Gainsborough Maintenance Limited | Households | 1984 |
| Gareth Thomas Surveying Ltd | Professional & scientific | 2026 |
| Gartan Properties Limited | Construction | 2015 |
| GAS Safety Cardiff Ltd | Construction | 2019 |
| GB Lifts Ltd | Manufacturing | 2023 |
| GEJ Carpentry Limited | Construction | 2017 |
| Gems Agency Ltd | Administrative & support | 2013 |
| Gems Casting Limited | Administrative & support | 2017 |
| Gentile Plumbing and Heating Limited | Construction | 2024 |
| Gents of Brooklyn Penarth Limited | Other services | 2020 |
| GEO Turf Consulting Limited | Professional & scientific | 2005 |
| Georgia Wiltshire Ltd | Professional & scientific | 2026 |
| Getalocum Ltd | Health & social care | 2025 |
| Gfys Limited | Real estate | 2021 |
| Ghina Initiative Limited | Hospitality | 2025 |
| Giite Limited | Real estate | 2024 |
| Giner Auto Parts Ltd | Wholesale & retail | 2024 |
| GJ Web Design Limited | Professional & scientific | 2016 |
| Gjhs Investments Limited | Real estate | 2024 |
| GJR Davies Limited | Information & communication | 2016 |
| Glamorgan Gardens Ltd | Professional & scientific | 2026 |
| Glamorgan Medical Limited | Health & social care | 2015 |
| Glamorgan Motors Limited | Wholesale & retail | 2018 |
| Glamorous Sky Ltd | Wholesale & retail | 2023 |
| Glanmor Court Management Ltd | Real estate | 2024 |
| Glass by Design Ltd | Wholesale & retail | 2015 |
| Glass Lion Holdings Ltd | Wholesale & retail | 2025 |
| Glassy Bits Ltd | Manufacturing | 2016 |
| Glastonbarry Limited | Arts & recreation | 2022 |
| Glenfields Management Consulting Limited | Professional & scientific | 2018 |
| Global Sports Data and Technology Group Ltd | Information & communication | 2019 |
| Glossa Praxis Ltd | Education | 2025 |
| Go Faster Stripe Limited | Information & communication | 2007 |
| Goaters Limited | Hospitality | 2024 |
| Gofannon Technical Services Limited | Professional & scientific | 2023 |
| Golate Court & 106 ST Mary Street Owners Management Company Limited | Households | 2022 |
| Gold Olive Consulting Ltd | Information & communication | 2012 |
| Golden Prosperity (UK) Limited | Professional & scientific | 2004 |
| Goldfinch Advice Limited | Financial services | 2021 |
| Goods Real Estate Ltd | Real estate | 2023 |
| Gordano Management Company Limited | Households | 1997 |
| Gracia Consult Ltd | Professional & scientific | 2007 |
| Gradientwork Limited | Information & communication | 2026 |
| Grak Ltd | Financial services | 2020 |
| Grayce Consulting Limited | Professional & scientific | 2012 |
| Graymatter Consulting Limited | Professional & scientific | 2020 |
| Green Eco-Options Limited | Construction | 2012 |
| Green Feet Limited | Professional & scientific | 2007 |
| Green Light Staffing Solutions Ltd | Administrative & support | 2026 |
| Green Modular Construction Solutions Ltd | Construction | 2021 |
| Green Palette Garden Design Ltd | Administrative & support | 2024 |
| Green Vale Recycling Limited | Water & waste | 2021 |
| Greenacres Holdco Ltd | Financial services | 2024 |
| Greenhill 1234 Limited | Real estate | 2007 |
| Greenlands (Penarth) Management Company Limited | Households | 1983 |
| Greenvale Building Contractors Ltd | Construction | 2022 |