| Gwenyn Ltd | Information & communication | 2025 |
| Gwyl Jazz Aberhonddu Limited | Administrative & support | 2025 |
| GXP Groundworks & Paving Ltd | Construction | 2024 |
| H&B Ltd | Extraterritorial | 2022 |
| H.C.Edwards and Sons Limited | Agriculture & fishing | 1960 |
| Harley Leisure Limited | Extraterritorial | 2001 |
| Harolds Field Management Company Limited | Households | 2005 |
| Harris Consultancy Services Limited | Professional & scientific | 2019 |
| Harris Offshore Ltd | Professional & scientific | 2022 |
| Hawk Haig Limited | Professional & scientific | 2004 |
| Hawkowl Ltd | Information & communication | 2006 |
| HAY Deli Limited | Wholesale & retail | 2015 |
| HAY Road Apartments Brecon Limited | Real estate | 2015 |
| HAY Takeaway Ltd | Hospitality | 2015 |
| Hay-Wired Homes Ltd | Real estate | 2021 |
| Haytek (Hay-On-Wye) Ltd | Information & communication | 2014 |
| HB Construction Brecon Ltd | Construction | 2024 |
| Heavy Firm Ltd | Transport & logistics | 2023 |
| Hello Deer Ltd | Information & communication | 2009 |
| Hello Deer Studios (About a Bell) Ltd. | Information & communication | 2024 |
| Hello Deer Studios Ltd. | Information & communication | 2022 |
| Herdman Coaches Limited | Transport & logistics | 2014 |
| Hereford Scaffolding Services Limited | Construction | 2012 |
| Heritage Theatr Cymru Ltd | Arts & recreation | 2024 |
| Higher and Hire MID Wales Ltd | Administrative & support | 2026 |
| Highgroundmaintenance Limited | Administrative & support | 2006 |
| Hills of Brecon Limited | Hospitality | 2024 |
| Himalayan Curry Brecon Ltd | Hospitality | 2023 |
| Himalayan Herbs Brecon Ltd | Hospitality | 2025 |
| Homely Learning Ltd | Education | 2021 |
| Hopkins & Hopkins Global CYF. | Administrative & support | 2026 |
| House on a Hill Ltd | Hospitality | 2017 |
| HOW Money Matters Ltd | Financial services | 2022 |
| Howagar Homes Limited | Households | 2002 |
| Howardale Limited | Manufacturing | 2016 |
| Hub Scaffolding & Rigging Ltd | Construction | 2015 |
| Huckbody Environmental Limited | Professional & scientific | 2006 |
| Hugslock Systems Ltd | Information & communication | 2012 |
| Humble Ltd | Administrative & support | 2022 |
| HUW Field Electrical Services Ltd | Construction | 2010 |
| Huxley Homes Limited | Real estate | 1995 |
| IBL Developments Ltd | Real estate | 2018 |
| IBL Group Ltd | Financial services | 2018 |
| IBL Property Services Limited | Construction | 2007 |
| Ihrs Matthews Limited | Professional & scientific | 2018 |
| Inbuild-Eth Limited | Extraterritorial | 2022 |
| Infovistauk Limited | Information & communication | 2024 |
| Infrastructure Access Ltd | Professional & scientific | 2024 |
| Insight Checker Ltd. | Wholesale & retail | 2023 |
| Insight Town Planning Ltd | Professional & scientific | 2008 |
| Inversion Limited | Manufacturing | 2006 |
| Island South Property Management Ltd | Hospitality | 2024 |
| J & C Griffiths Agricultural Engineers Limited | Wholesale & retail | 2013 |
| J & P Engineering (Powys) Limited | Wholesale & retail | 2017 |
| J T Credland Garden Services Ltd | Agriculture & fishing | 2026 |
| J Thomas Tree Services Ltd | Agriculture & fishing | 2020 |
| Jadore Ltd | Other services | 2025 |
| James Dean the Estate Agents Ltd | Real estate | 2025 |
| James Luckhurst Associates Ltd | Information & communication | 2012 |
| James Thomas (Merthyr) Limited | Agriculture & fishing | 1976 |
| Jangel Group Properties Limited | Real estate | 2025 |
| Jansson Ltd | Hospitality | 2026 |
| Jayne Partnership Limited | Professional & scientific | 2010 |
| JBW Davies Consulting Ltd | Professional & scientific | 2024 |
| Jericho Brass Limited | Information & communication | 2021 |
| Jess MAC Ltd | Other services | 2017 |
| Jessica Galletta-Williams Ltd | Other services | 2023 |
| JHN GIN Ltd | Wholesale & retail | 2021 |
| JJ Water Management Limited | Water & waste | 2007 |
| JJB Associates Ltd | Information & communication | 2020 |
| John Williams Transport Ltd | Transport & logistics | 2009 |
| Jolly Good Stays Ltd | Hospitality | 2022 |
| JON Edmonds Validation Consultants Ltd | Professional & scientific | 2006 |
| Jones & Fraser Limited | Construction | 2009 |
| Joseph Property Holdings Limited | Construction | 2018 |
| Jrj&Jp Ltd | Hospitality | 2024 |
| Juliana ML Properties Ltd | Real estate | 2025 |
| Just Mammals Limited | Professional & scientific | 2020 |
| JV Jones Properties Ltd | Other services | 2013 |
| JW Consultants Limited | Professional & scientific | 2014 |
| JWC Investments Limited | Real estate | 2020 |
| K G Wilce Limited | Construction | 2001 |
| K H & J Partners Limited | Financial services | 2026 |
| K P Install Ltd | Administrative & support | 2023 |
| K&0 Table and Event Ltd | Hospitality | 2025 |
| K1 Mini Market Ltd | Hospitality | 2024 |
| K15 Solutions Ltd | Construction | 2023 |
| Kandahena Estates Limited | Real estate | 2003 |
| Karatech Ltd | Professional & scientific | 2013 |
| KAY B Ltd | Professional & scientific | 2025 |
| Kaye Carmichael Limited | Professional & scientific | 2019 |
| KCO Barbering Services Ltd | Other services | 2024 |
| Keddle Construction Ltd | Construction | 2015 |
| Keppe Rofer Limited | Professional & scientific | 2013 |
| Kesri Smolas Ltd | Professional & scientific | 2006 |
| Key Talent Coaching Limited | Other services | 2022 |
| King Morter Proud & Co Limited | Professional & scientific | 2010 |
| Kirsty DE Sylva Limited | Health & social care | 2019 |
| Kivancfood Limited | Hospitality | 2021 |
| Kobudai Dynamics Limited | Professional & scientific | 2024 |