| Four ASH Court Management Company Limited | Households | 1974 |
| Fourth Wall Property Limited | Households | 2020 |
| FOX Cottage Homes Ltd | Real estate | 2018 |
| Foxtrot Alpha Recordings Limited | Arts & recreation | 2016 |
| Freemont Baxter Limited | Arts & recreation | 2013 |
| Freshprime Limited | Administrative & support | 2009 |
| Freshwater Projects Limited | Construction | 2011 |
| Frog Filling Stations Ltd | Wholesale & retail | 2020 |
| Fundamental Plus Ltd | Professional & scientific | 2018 |
| G J R Machinery Ltd | Manufacturing | 2014 |
| G. Robinson & Associates Limited | Professional & scientific | 1990 |
| Gallery at Home Limited | Wholesale & retail | 2023 |
| Galletleys of USK Ltd | Manufacturing | 2022 |
| Gallop (Monmouth) Ltd | Professional & scientific | 2025 |
| Gareth Coombes Consultancy Limited | Education | 2012 |
| Gareth Coombes Resources Limited | Education | 2014 |
| GCS Operations Limited | Professional & scientific | 2025 |
| GD Building and Maintaince Ltd | Construction | 2026 |
| Gerrymet Limited | Manufacturing | 1979 |
| Gjbl Holding Limited | Professional & scientific | 2024 |
| GL Commercial Group Ltd | Extraterritorial | 2018 |
| Glen-Yr-Afon Holdings Limited | Hospitality | 2008 |
| Glen-Yr-Afon House Hotel Limited | Hospitality | 2001 |
| GN Group Ltd | Construction | 2020 |
| Goldcroft Mortgages Ltd | Financial services | 2024 |
| Grange Organics Limited | Agriculture & fishing | 2006 |
| Grant Start Ltd | Professional & scientific | 2023 |
| Greannach & Crosta Ltd | Information & communication | 2026 |
| Green Kleen Ltd | Administrative & support | 2026 |
| Greenlea Consulting Limited | Professional & scientific | 2020 |
| Greenstone Farm Limited | Households | 2014 |
| GRH Building Contractors LLP | | 2025 |
| Grid Xitek Limited | Professional & scientific | 1995 |
| Griffith Memorials (Newport) Ltd | Other services | 2018 |
| Griffith Memorials Limited | Other services | 2010 |
| Griffiths Design Limited | Professional & scientific | 2019 |
| Griffiths Property Development Limited | Households | 2022 |
| Grip Sports Limited | Arts & recreation | 2025 |
| Gwent Consultancy Ltd | Professional & scientific | 2016 |
| GX Design Engineers Ltd. | Professional & scientific | 2012 |
| GX Environmental Limited | Professional & scientific | 2007 |
| GX Group Limited | Professional & scientific | 2022 |
| Gymbeats Limited | Arts & recreation | 2019 |
| H&J Byrne LLP | | 2018 |
| Habitable Planet Limited | Information & communication | 2007 |
| Hambly Estates Limited | Real estate | 2023 |
| Hand Crafted Furniture Limited | Manufacturing | 2015 |
| Hannonmedia Limited | Health & social care | 1999 |
| Harleys Hogroasts Limited | Extraterritorial | 2015 |
| Harleys Hogroasts USK Ltd | Hospitality | 2022 |
| Harviz Holdings Limited | Financial services | 2016 |
| Hatched Marketing Ltd | Professional & scientific | 2018 |
| HCB Engineering Ltd | Professional & scientific | 2020 |
| HE IS Risen Productions Ltd | Arts & recreation | 2025 |
| Head TAG Limited | Information & communication | 2012 |
| Heart 2 Hart Solutions Ltd | Health & social care | 2014 |
| Heavenearth Limited | Wholesale & retail | 2002 |
| Helen's Homebakes Limited | Manufacturing | 2003 |
| Hera Support Limited | Information & communication | 2025 |
| Holly House Wellness Limited | Health & social care | 2021 |
| Home Whisperers Holdings Limited | Real estate | 2016 |
| Hudson Trustees Limited | Administrative & support | 2020 |
| Hughes Bros.(Usk)Limited | Real estate | 1964 |
| Hughes Butterfield Limited | Agriculture & fishing | 2007 |
| Hywan Property Limited | Construction | 2016 |
| IN This 2GETHER Limited | Health & social care | 2023 |
| Industry Learning Solutions Ltd | Administrative & support | 2018 |
| Invasive Knotweed Solutions Ltd | Professional & scientific | 2020 |
| Ioan Jenkins Limited | Professional & scientific | 2024 |
| Isca Property Holdings Limited | Real estate | 2006 |
| Itcom Consulting Limited | Information & communication | 2014 |
| Izotope Financial Solutions Limited | Information & communication | 2018 |
| J J Livestock Solutions Limited | Agriculture & fishing | 2017 |
| J.& D.Freeman Limited | Agriculture & fishing | 1959 |
| James Brindley Fabrics Limited | Wholesale & retail | 2019 |
| James Cornfield Ltd | Transport & logistics | 2024 |
| Jasd Property Limited | Real estate | 2019 |
| JD Mortgages Limited | Financial services | 2023 |
| Jemtech Solutions Ltd | Manufacturing | 2015 |
| Jenna L Fowler Ltd | Professional & scientific | 2013 |
| Jensen-Faulkner Limited | Construction | 1991 |
| JER Estates Ltd | Real estate | 2023 |
| Jericho Merchant Limited | Real estate | 2002 |
| Jewels & Gems Bridal Ltd | Wholesale & retail | 2024 |
| Jewels & Gems Outlet Ltd | Wholesale & retail | 2026 |
| Jgtproperty Ltd | Real estate | 2020 |
| Jhsc Medical Limited | Health & social care | 2016 |
| JIM Jams Direct Limited | Wholesale & retail | 2015 |
| JL Residential Limited | Real estate | 2024 |
| JON LB IFA Ltd | Financial services | 2024 |
| Jones of USK Construction Services Ltd | Construction | 2011 |
| JSP Advisory Limited | Professional & scientific | 2015 |
| Justin Samuel Associates Limited | Professional & scientific | 2021 |
| Jypsychol Limited | Education | 2024 |
| K & R Cardiff Limited | Manufacturing | 2024 |
| K G Morris Timber Ltd | Agriculture & fishing | 2011 |
| KBR Consultants Ltd | Information & communication | 2020 |
| Keepers Lodge Clay Shoot Limited | Agriculture & fishing | 2008 |
| Kelly Jones Associates Limited | Education | 2015 |
| KID Rapt Limited | Wholesale & retail | 1992 |