| Harris Consulting IOW Limited | Financial services | 2007 |
| Harris Floor Screeding Group Limited | Construction | 2021 |
| Harris-Honrado GAS Services Ltd | Construction | 2022 |
| Harrison Grace Legal Limited | Professional & scientific | 2025 |
| Harrison Rabbitt Hair Studio Limited | Other services | 2021 |
| Harrison’S Engineering Ltd | Construction | 2025 |
| Harry Manpower Solutions Ltd | Administrative & support | 2024 |
| Hartland Partners Limited | Professional & scientific | 2017 |
| Hartless Estates Ltd | Real estate | 2025 |
| Hartless Properties Ltd | Real estate | 2025 |
| Hartley Events Ltd | Professional & scientific | 2020 |
| Hartpark Limited | Health & social care | 2001 |
| Hartshorne’S Ltd | Real estate | 2025 |
| Harty and Harty Limited | Professional & scientific | 2012 |
| Harvey Smith Research Consulting Limited | Professional & scientific | 2026 |
| Harvey T Ross Ltd | Construction | 2023 |
| Harvey's of Yarmouth Limited | Wholesale & retail | 2011 |
| Harwa Estates Limited | Real estate | 2024 |
| Harwa Limited | Information & communication | 2026 |
| Harwa Properties Limited | Real estate | 2026 |
| Haseley Manor Functions Limited | Hospitality | 2001 |
| Hashtag TAN Limited | Other services | 2015 |
| Hastings & District Transport Limited | Extraterritorial | 2019 |
| Hatch'D Ltd | Professional & scientific | 2025 |
| Hatkora Junction Limited | Hospitality | 2019 |
| Hatom Ltd | Manufacturing | 2020 |
| Hatton Apartments Ltd | Hospitality | 2023 |
| Haus 22 Ltd | Other services | 2020 |
| Haus of AWE Ltd | Other services | 2022 |
| Haus of Skin & Laser Ltd | Other services | 2025 |
| Havard Stables RDA Centre CIC | Health & social care | 2023 |
| Haven Key Properties Ltd | Real estate | 2025 |
| Haven Property Developments Limited | Real estate | 2024 |
| Havoc Squad Limited | Administrative & support | 2024 |
| Haw-Wah Ltd | Administrative & support | 2025 |
| Hawarden Motors Limited | Wholesale & retail | 2009 |
| Hawk Property Ventures Limited | Extraterritorial | 2015 |
| Hawke Assessments Ltd | Professional & scientific | 2024 |
| Hawkfire Developments Limited | Real estate | 2004 |
| Hawkins Residents Limited | Households | 1997 |
| Hawliau CYF. | Education | 2015 |
| Haya by Hawa Limited | Wholesale & retail | 2025 |
| HAYAT7 Ltd | Hospitality | 2025 |
| Hayes Enterprise Ltd | Health & social care | 2014 |
| Hayes Property Developers Limited | Construction | 2002 |
| Hayl Ltd | Transport & logistics | 2020 |
| Hayle Holding Ltd | Construction | 2018 |
| Hayward Pensions Limited | Financial services | 2017 |
| Hayward Sestini Pensions Limited | Financial services | 2016 |
| Hazell Tech Services Limited | Information & communication | 2015 |
| Hazells Developments Limited | Real estate | 2001 |
| Hazells Enterprises Limited | Real estate | 2001 |
| HB Collective Limited | Wholesale & retail | 2013 |
| HB Jackson Limited | Financial services | 2019 |
| Hbcsf Limited | Wholesale & retail | 2005 |
| HC (Cowes) Limited | Households | 2015 |
| HCH Equestrian Limited | Professional & scientific | 2026 |
| HCI Systems Limited | Manufacturing | 2012 |
| HCM (Porthcawl) Limited | Health & social care | 2014 |
| HD Cuts (Risca) Ltd | Other services | 2026 |
| HD Gate Automation Ltd | Manufacturing | 2016 |
| HD Plant Hire (UK) Ltd | Extraterritorial | 2012 |
| HD Waste Commercial Ltd | Water & waste | 2022 |
| HDS Ultrasonics Limited | Manufacturing | 2015 |
| HE Assets Limited | Administrative & support | 2021 |
| Head Quarters Hair Studio Limited | Other services | 2013 |
| Headrush (Newport) Limited | Other services | 2014 |
| Heads Shoulders Dance and Sing Ltd | Financial services | 2012 |
| Heal Medigrade Ltd | Wholesale & retail | 2024 |
| Healey Haulage Limited | Transport & logistics | 2017 |
| Healey Property Services Ltd | Manufacturing | 2024 |
| Healthcare Installations Ltd | Public administration | 2018 |
| Healthcic Services Limited | Administrative & support | 2012 |
| Healthwell Solutions (IW) Ltd | Other services | 2021 |
| Healthy High Ltd | Hospitality | 2025 |
| Heartstones Ltd | Manufacturing | 2026 |
| Heartxhouse Ltd | Professional & scientific | 2025 |
| Heath Gardens Management Company Limited | Households | 2015 |
| Heath Hill Enterprises Limited | Real estate | 2022 |
| Heather Homes Limited | Real estate | 2000 |
| Heathermount Projects Ltd | Construction | 2022 |
| Heathfield Holidays Limited | Hospitality | 2025 |
| Heathlands Management Company Limited | Households | 1988 |
| Heatstar Limited | Manufacturing | 1980 |
| Heatup Floor Ltd | Construction | 2018 |
| Heaven 11 Convenience Store Limited | Wholesale & retail | 2025 |
| Heavenly Ledger Ltd | Professional & scientific | 2025 |
| Heavenly Lifestlye Care Limited | Health & social care | 2025 |
| Hebe Group Limited | Financial services | 2019 |
| Hebe Lakes Ltd | Real estate | 2020 |
| Hebe Rassau 20 Ltd | Real estate | 2022 |
| Helden Care Agency Limited | Health & social care | 2009 |
| Helen Bristol Limited | Other services | 2023 |
| Helen Nails 6868 Ltd | Other services | 2024 |
| Heliaxis Limited | Construction | 2025 |
| Heliorelondon Ltd | Wholesale & retail | 2026 |
| Helios Fire & Construction Consultancy Ltd | Professional & scientific | 2019 |
| Heliossolar Limited | Construction | 2021 |
| Hello Financial Planning Ltd. | Professional & scientific | 2020 |
| Hellyer Catering Ltd | Hospitality | 2021 |