| Happy Feet Carpets Ltd | Construction | 2026 |
| Happy Gourmet Ltd | Hospitality | 2020 |
| Happy Mouse Limited | Real estate | 2017 |
| Happy's Desi Jikoni Ltd | Hospitality | 2020 |
| Hararious Ltd | Real estate | 1998 |
| Harbury Consulting Limited | Administrative & support | 2010 |
| Hard HAT Construction Group Limited | Financial services | 2023 |
| Hard HAT Creative Ltd | Professional & scientific | 2024 |
| Hard HAT Trustee Limited | Financial services | 2023 |
| Hard Rock MN Limited | Health & social care | 2020 |
| Hard Times London Limited | Arts & recreation | 2013 |
| Harding Events Ltd | Hospitality | 2024 |
| Harding Group Limited | Construction | 2005 |
| Harding Homes (East Anglia) Limited | Construction | 2000 |
| Harding Homes (the Willows) Limited | Construction | 2018 |
| Harding Homes Limited | Extraterritorial | 2023 |
| Harding Investments (Crouch Street) Limited | Real estate | 2021 |
| Harding Investments Limited | Construction | 2001 |
| Harding Properties Limited | Construction | 2023 |
| Harding Property Investments Ltd | Real estate | 2023 |
| Hardinvale Limited | Real estate | 2002 |
| Hardwicke Contracts Limited | Administrative & support | 2014 |
| Hardy Vintage Ltd | Wholesale & retail | 2020 |
| Harikel Home Improvement Ltd | Other services | 2022 |
| Harikel Properties Ltd | Real estate | 2021 |
| Harise Ltd | Real estate | 2025 |
| Harley DEE Limited | Construction | 2021 |
| Harleyphysiotherapy Limited | Health & social care | 2013 |
| Harlow Property Holdings Limited | Construction | 2020 |
| Harlow Van Hire Limited | Administrative & support | 2014 |
| Harmer Trading Limited | Professional & scientific | 2021 |
| Harmond Marketing Consultancy Ltd | Professional & scientific | 2025 |
| Harpar Global Ltd | Professional & scientific | 2025 |
| Harper Fencing Limited | Construction | 2001 |
| Harperdan Consulting Limited | Extraterritorial | 2018 |
| Harrington Bar Group Ltd | Hospitality | 2023 |
| Harris & Co Commercial Management Limited | Professional & scientific | 2012 |
| Harris & Partners Limited | Professional & scientific | 1998 |
| Harris Hire (Hockley) Limited | Administrative & support | 2013 |
| Harris Trading Limited | Real estate | 2013 |
| Harris Transport Limited | Extraterritorial | 2025 |
| Harris Transportation Limited | Transport & logistics | 2019 |
| Harrison Quality Consultancy Ltd | Other services | 2017 |
| Harrisonsrentalproperties Ltd | Real estate | 2024 |
| Harristar Ltd | Information & communication | 2018 |
| Harrop Healthcare Limited | Wholesale & retail | 2020 |
| Harrow Stirling Ltd | Construction | 2025 |
| Harry Flashmans Ltd | Other services | 2014 |
| Harry Monk Enterprises Limited | Professional & scientific | 1997 |
| Harry Turner Family Limited | Agriculture & fishing | 2010 |
| Harry's Plumbing & Heating Limited | Construction | 2021 |
| Harry’S Boilers Limited | Construction | 2022 |
| Hartigan Software Design Limited | Information & communication | 1987 |
| Hartwell Design Limited | Information & communication | 2024 |
| Hartwell Industries Limited | Information & communication | 2024 |
| Hartwell Software Limited | Information & communication | 2024 |
| Hartwell Tech Limited | Information & communication | 2024 |
| Hartwell.Io Limited | Information & communication | 2024 |
| Harvard Hall Limited | Real estate | 2021 |
| Harvesters Farm Kennels Ltd | Hospitality | 2010 |
| Harvey Estates Ltd | Real estate | 2023 |
| Harvey Homes Ltd | Hospitality | 2025 |
| Harvey Property Limited | Real estate | 2014 |
| Harvey Residential Ltd | Real estate | 2019 |
| Harwils Investments Ltd | Financial services | 2022 |
| Harwood Mortgage Solutions Ltd | Financial services | 2024 |
| Harwoods of Kent (Tenterden) Ltd | Wholesale & retail | 2020 |
| Harwoods of Kent Limited | Wholesale & retail | 2011 |
| Harwoods of London (New Covent Garden) Limited | Professional & scientific | 2008 |
| Harwoods of London Limited | Wholesale & retail | 2003 |
| Haryana in UK Ltd | Other services | 2015 |
| Hasprop Properties Limited | Real estate | 2026 |
| Hatch Commerce Limited | Information & communication | 2022 |
| Hatfield Peverel Fish & Chips Ltd | Hospitality | 2018 |
| Hatfield Peverel Surgery Limited | Health & social care | 2009 |
| Hatfield Wick CIC | Education | 2024 |
| Hatfield Wick Education Ltd | Education | 2020 |
| Hathi Locums Limited | Health & social care | 2018 |
| Hatsncaps Ltd | Wholesale & retail | 2025 |
| Hatton Inc Ltd | Manufacturing | 2021 |
| Hatton Legal Marketing LLP | | 2020 |
| Haul-In-One.Com Limited | Financial services | 2010 |
| Hausofglamour TM Ltd | Manufacturing | 2021 |
| Haven of Natural Health Therapies Ltd. | Professional & scientific | 2009 |
| Haven Port Homes Ltd | Real estate | 2018 |
| Havenmire Ltd | Wholesale & retail | 2022 |
| Havering Plant Hire Limited | Construction | 2019 |
| Hawk-Eye Property Check Ltd | Households | 2024 |
| Hawkbay Management Limited | Professional & scientific | 2007 |
| Hawkgrove Limited | Information & communication | 1992 |
| Hawkins Property Ltd | Real estate | 2025 |
| Hawkstone Netball Club CIC | Education | 2025 |
| Hawthorn Consulting (Essex) Ltd | Construction | 2025 |
| Hawthorne & Sons Building Limited | Construction | 2026 |
| Haych Group Ltd | Construction | 2026 |
| Haycroft Properties Ltd | Real estate | 2022 |
| Haydec Properties Limited | Real estate | 2024 |
| Hayes Close Property Limited | Real estate | 2008 |
| Haypigs Limited | Wholesale & retail | 2016 |
| Haytan Health Care Services Ltd | Public administration | 2022 |