| HDL Property Group Ltd | Construction | 2024 |
| Hdldm Parks Limited | Hospitality | 2015 |
| HDS (South Wales) Limited | Wholesale & retail | 2020 |
| HE Placement Solutions Ltd | Information & communication | 2022 |
| Headline Music School Ltd | Education | 2025 |
| Heads of the Valley Recycling Ltd | Mining & quarrying | 2021 |
| Healics CYF | Real estate | 2017 |
| Health and Wellbeing 360 Ltd | Professional & scientific | 2024 |
| Health Island Ltd | Wholesale & retail | 2020 |
| Health Performance Education Ltd | Other services | 2016 |
| Healthcare by Morris Ltd | Financial services | 2022 |
| Healthleads U.K. Holdings Limited | Professional & scientific | 2025 |
| Healthy and Happy Ltd | Health & social care | 2023 |
| Healthy Workstations Limited | Wholesale & retail | 2002 |
| Heaman Software Ltd | Information & communication | 2026 |
| Hear Again Ltd | Wholesale & retail | 2020 |
| Heareka Labs Ltd | Wholesale & retail | 2024 |
| Heat Pump Services Ltd | Construction | 2009 |
| Heaterup Ltd | Construction | 2024 |
| Heath Court Management Limited | Households | 1986 |
| Heatherslade Hotel Limited | Hospitality | 1977 |
| Heatherslade Retirement Home Limited | Administrative & support | 2006 |
| Heathfield Court Management (Swansea) Limited | Hospitality | 1990 |
| Heathfield Lodge Limited | Health & social care | 2010 |
| Heathfield Management Limited | Real estate | 2011 |
| Heathfield Property Swansea Limited | Real estate | 2024 |
| Heatlex Group Installations Ltd | Construction | 2019 |
| Heatsource (Wales) Limited | Construction | 2012 |
| Heatwave Marketing Ltd | Professional & scientific | 2013 |
| Heaven Hair & Beauty Emporium Limited | Real estate | 2016 |
| Heavens Assessors Ltd | Professional & scientific | 2025 |
| Heldale Group Ltd | Manufacturing | 2025 |
| Heldale Ltd | Real estate | 2021 |
| Helen Jenkins Medical Services Limited | Health & social care | 2023 |
| Helios Solar PV Limited | Construction | 2026 |
| Heliox Maritime Ltd | Professional & scientific | 2011 |
| Helix 21 Limited | Construction | 2013 |
| Helix Plumbing and GAS Limited | Construction | 2023 |
| Hell Bent on Cement Ltd | Manufacturing | 2025 |
| Hell on Shirts Ltd | Wholesale & retail | 2019 |
| Hello Asia Ltd | Wholesale & retail | 2025 |
| Hello New Home 2 Limited | Real estate | 2021 |
| Help Media Ltd | Information & communication | 2024 |
| Helpfavour Limited | Real estate | 1992 |
| Helpline Services UK Limited | Administrative & support | 2021 |
| Helwick Limited | Professional & scientific | 2024 |
| Hemam Limited | Health & social care | 2023 |
| Hemani Limited | Real estate | 2007 |
| Hemingway Financial Services Ltd. | Financial services | 2016 |
| Henclo MAN Ltd | Households | 2004 |
| Henderson and Henley Limited | Health & social care | 2021 |
| Hendre GAS Services Ltd | Construction | 2021 |
| Hendre Road Ltd | Real estate | 2025 |
| Hendrefoilan Court Management Company Limited | Households | 1986 |
| Hendrefoilan Development Ltd | Construction | 2020 |
| Hendy Close Management Company Limited | Households | 2002 |
| Hendy Daycare Limited | Health & social care | 2025 |
| Hendy Trading Ltd | Wholesale & retail | 2025 |
| Hengoed Court Limited | Health & social care | 2012 |
| Hengoed Davies Limited | Construction | 2007 |
| Hengoed Holdings Limited | Professional & scientific | 2007 |
| Hengoed Manor Limited | Health & social care | 2018 |
| Hengoed Park (Swansea) Limited | Health & social care | 2009 |
| Hengxing 298 Limited | Hospitality | 2024 |
| Henler Ltd | Professional & scientific | 2024 |
| Henning Williams Property Limited | Hospitality | 2022 |
| Henry MAY Property Management Ltd | Real estate | 2003 |
| Hentons Home Improvements Ltd | Construction | 2012 |
| Henty Building Services Ltd | Construction | 2001 |
| Heol LAS Park Association CIC | Arts & recreation | 2024 |
| Heol Newydd Management Company Ltd | Professional & scientific | 2016 |
| Heol Property Group Limited | Administrative & support | 2024 |
| HER Turn Ventures Ltd | Arts & recreation | 2026 |
| Herbal Clinic Herbs Ltd | Health & social care | 2026 |
| Herbal Clinic Swansea Ltd | Health & social care | 2024 |
| Herbie and Josh Ltd | Wholesale & retail | 2021 |
| Herefordshire Urology Limited | Health & social care | 2016 |
| Herfclubuk Ltd | Wholesale & retail | 2025 |
| Heritage Barbers Ltd | Other services | 2024 |
| Heritage Hold Co. Ltd | Wholesale & retail | 2025 |
| Heritage Life Horizons CIC | Education | 2025 |
| Heritage Screenprint Limited | Manufacturing | 1977 |
| Hermes Travel Europe Limited | Administrative & support | 2025 |
| Herms Construction Limited | Construction | 2022 |
| Heronsgate Skincare Ltd | Administrative & support | 2010 |
| Heronstone Engineering Limited | Manufacturing | 2008 |
| Heronstone Lodges Limited | Hospitality | 2008 |
| HES Fire and Security Limited | Construction | 2019 |
| Heshima | Health & social care | 2005 |
| Hevi Community Centre CIC | Education | 2025 |
| HEX8 Automotive Limited | Information & communication | 2019 |
| Hexagon Wealth Limited | Financial services | 2002 |
| Hexco Ltd | Real estate | 2018 |
| HEY Living Ltd | Hospitality | 2022 |
| HG Property Investments Ltd | Real estate | 2020 |
| HG3Y Ltd | Hospitality | 2019 |
| HGR Carpentry Limited | Construction | 2013 |
| HGV Spares Limited | Manufacturing | 2012 |
| HGV Supplies Ltd | Professional & scientific | 2015 |
| HHE Properties Ltd | Real estate | 2020 |