| Handmade Welsh Home Fragrance Company Limited | Manufacturing | 2021 |
| Hang 10 Medical Ltd | Health & social care | 2025 |
| Hangarlabs Ltd | Information & communication | 2025 |
| Hannah Clare Hair Ltd | Other services | 2025 |
| Hannah Vera Deborah Roddis Limited | Extraterritorial | 2024 |
| Happy 2026 Limited | Hospitality | 2026 |
| Happy Days Stays Ltd | Hospitality | 2023 |
| Happy Little Dragons Ltd | Health & social care | 2025 |
| Happy Valley (Porthcawl) Holiday Camp Limited | Hospitality | 1959 |
| Harbel Consulting Ltd | Information & communication | 2022 |
| Harbel Estates Ltd | Real estate | 2023 |
| Harbour Home Cefn Ltd | Hospitality | 2025 |
| Hard Healthcare Ltd | Health & social care | 2020 |
| Hardwerks Ltd | Manufacturing | 2025 |
| Harhys Limited | Hospitality | 2014 |
| Harlequin Home Care Ltd | Health & social care | 2018 |
| Harmony Homes Group Limited | Real estate | 2024 |
| Harperhadley Ltd | Wholesale & retail | 2021 |
| Harries Rail Solutions Limited | Construction | 2018 |
| Harries Watkins & Jones Ltd | Professional & scientific | 2002 |
| Harries Watkins Jones PS LLP | | 2021 |
| Harriet Rose Terri ANN Owen Limited Limited | Extraterritorial | 2024 |
| Harry’S Sandwich Shop Limited | Hospitality | 2025 |
| Hartdell Limited | Wholesale & retail | 2024 |
| Hartfray Limited | Wholesale & retail | 2024 |
| Hartmain Limited | Other services | 2024 |
| Hassle Free Weddings Limited | Other services | 2017 |
| Hathagraphics Limited | Professional & scientific | 2003 |
| Hathaways Hearing and Skin Solutions Ltd | Other services | 2025 |
| Haul and Go Limited | Transport & logistics | 2025 |
| Haulfryn Liquid Screeding Limited | Construction | 2020 |
| Hauly Rollers Ltd | Transport & logistics | 2016 |
| Haus of GIN Limited | Hospitality | 2019 |
| Haus of Glam Ltd | Other services | 2023 |
| Haus of SIN Limited | Hospitality | 2020 |
| Haus of Tans Limited | Other services | 2019 |
| Have Your SAY Limited | Professional & scientific | 2016 |
| Hawen Limited | Real estate | 2021 |
| Hawk Shadow Audio Ltd | Wholesale & retail | 2020 |
| Hawk-Eye Security Systems Limited | Administrative & support | 2006 |
| Hawkeyes Security Ltd | Administrative & support | 2024 |
| Hawkstone Farley Group Ltd | Wholesale & retail | 2022 |
| Hawthorn Accountancy Solutions Ltd | Professional & scientific | 2003 |
| Hayseed Education Ltd | Information & communication | 2025 |
| Haywain Court Management Limited | Households | 1991 |
| Hayward Utility Services Limited | Construction | 2017 |
| Hbdp UK Ltd | Hospitality | 2018 |
| HC Strategies Ltd | Education | 2023 |
| HD Limited | Real estate | 2008 |
| HD Safety Ltd | Professional & scientific | 2024 |
| Healer Surveys Limited | Professional & scientific | 1999 |
| Health Care 101 Ltd | Health & social care | 2024 |
| Healthcare@Oak Tree Limited | Health & social care | 2014 |
| Hearthstone Developments LLP | | 2026 |
| Heidharl Ltd | Construction | 2017 |
| Helen Jane Evans Limited | Financial services | 2015 |
| HELPINGHANDSCOUNSELLING4ALL Ltd | Health & social care | 2025 |
| Hendir Uchaf Solar Ltd | Energy | 2024 |
| Hendre Post Holdings Limited | Agriculture & fishing | 2017 |
| Hengoed Memorials Limited | Other services | 2009 |
| Henry & Sons Bridgend Limited | Hospitality | 2021 |
| Heol Y CYW Community Sports Ltd | Arts & recreation | 2023 |
| Hephaestus Talos Ltd | Information & communication | 2024 |
| Herbology Ltd | Wholesale & retail | 2025 |
| Heritage Clay Tiles Limited | Wholesale & retail | 2004 |
| Heritage House (Ogmore) Management Company Limited | Real estate | 2005 |
| Herochew Ltd | Wholesale & retail | 2025 |
| Hetlelid Invest Limited | Extraterritorial | 2010 |
| HEY AL Limited | Other services | 2024 |
| HFM Maintenance Limited | Professional & scientific | 2019 |
| HFS Agriculture Limited | Wholesale & retail | 2009 |
| Hicks & Carter Electrical Services Ltd | Construction | 2015 |
| Hicorp 18 Limited | Professional & scientific | 2008 |
| Hiddlestone & SON Limited | Wholesale & retail | 1981 |
| High Hopes Psychology Services Ltd | Health & social care | 2024 |
| High Steele Solutions Ltd | Construction | 2022 |
| Highbeck Limited | Extraterritorial | 2026 |
| Higher Degree Therapy Ltd | Health & social care | 2025 |
| Higher Spirits Limited | Hospitality | 2018 |
| Highfield Human Resources Ltd | Administrative & support | 2017 |
| Highland Construction (Bridgend) Limited | Construction | 2019 |
| Highland Electrix (Bridgend) Limited | Construction | 1966 |
| Highport Limited | Construction | 2025 |
| Highreel Limited | Extraterritorial | 2025 |
| Hiitfitness Ltd | Health & social care | 2025 |
| Hillacre Limited | Extraterritorial | 2026 |
| Hillandale (Wales) Limited | Construction | 1970 |
| Hillbest Limited | Construction | 2024 |
| Hillgate Limited | Extraterritorial | 2025 |
| Hillh Limited | Wholesale & retail | 2025 |
| Hillman Mechanical Repair Services Ltd | Wholesale & retail | 2018 |
| Hillmere Limited | Extraterritorial | 2021 |
| Hillplan Limited | Extraterritorial | 2021 |
| Hillride Limited | Extraterritorial | 2026 |
| Hillsview Properties Ltd | Real estate | 2017 |
| Hilton Logistics Ltd | Transport & logistics | 2023 |
| Hiraeth Silver Ltd | Manufacturing | 2024 |
| Hirwaun Homes & Recreation Company Limited | Construction | 2012 |
| Hitch N Putt Limited | Administrative & support | 2026 |
| Hitchings Electrical (Cowbridge) Limited | Construction | 2013 |