| Homelodge Buildings Limited | Construction | 1986 |
| Homes on the Spot Limited | Real estate | 2024 |
| Honest Property Ltd | Real estate | 2016 |
| Honey + Harveys Limited | Financial services | 2017 |
| Honey Lane Developments Ltd | Construction | 2013 |
| Honeyhawk Limited | Professional & scientific | 1991 |
| Honeysuckle Holidays Ltd | Hospitality | 2006 |
| Honeywick Consulting Limited | Information & communication | 2021 |
| Hootiq Ltd | Information & communication | 2025 |
| HOP Training Ltd | Education | 2015 |
| Hope & MAE Ltd | Professional & scientific | 2022 |
| Hope Church Winchester | Other services | 2009 |
| Hope Davis Consulting Ltd | Professional & scientific | 2009 |
| Hopkins Cloud Services Limited | Information & communication | 2024 |
| Hopps Partners Ltd | Administrative & support | 2025 |
| Horizonview Group Ltd | Real estate | 2024 |
| Horn Farming Limited | Agriculture & fishing | 2014 |
| Hornbeam Management Limited | Real estate | 2002 |
| Horncroft (NO 1) Limited | Professional & scientific | 2006 |
| Horncroft (NO 2) Limited | Professional & scientific | 2006 |
| Horseshoe Bay Promenade Limited | Professional & scientific | 2016 |
| Hosei Moons Limited | Arts & recreation | 2023 |
| Hosking & Co Ltd | Administrative & support | 2025 |
| Hot and Cold Technical (UK) Limited | Construction | 2006 |
| Hot CUP Components Limited | Information & communication | 2020 |
| Hot Minute Ltd | Professional & scientific | 2022 |
| Housden & Co. Ltd | Professional & scientific | 2006 |
| House and Garden Services Ltd | Construction | 2022 |
| House and Holiday Home Mortgages Ltd | Financial services | 2015 |
| House Mail Order (Holdings) Limited | Financial services | 2020 |
| House of BOO Ltd | Professional & scientific | 2020 |
| House of Khan Limited | Extraterritorial | 2023 |
| Howe Land Profits Ltd | Real estate | 2025 |
| Howes Sporting Club Limited | Agriculture & fishing | 2023 |
| Howie Labs Limited | Wholesale & retail | 2022 |
| HR First Limited | Administrative & support | 2000 |
| HRE Land Profits Ltd | Real estate | 2025 |
| Hub Connect Limited | Information & communication | 2016 |
| Hugh Lumby Advisory Limited | Construction | 2020 |
| Hugo Barbers Limited | Other services | 2014 |
| Huichang(Uk) Ltd | Wholesale & retail | 2024 |
| Human LED Ltd. | Administrative & support | 2014 |
| Humbeat Limited | Professional & scientific | 2016 |
| Humphrey Holdco Limited | Professional & scientific | 2022 |
| Hun-Holding Ltd. | Administrative & support | 2017 |
| Hundentours Limited | Administrative & support | 2014 |
| Hundred L Culture Ltd | Manufacturing | 2025 |
| Hunt Health Nutrigenomics Ltd | Health & social care | 2022 |
| Huntershrave Management Limited | Households | 2016 |
| Huntgrange Ltd | Wholesale & retail | 2023 |
| Huntland Land Profits Limited | Real estate | 2025 |
| Hunyadi Limited | Professional & scientific | 2025 |
| HUQ Industries Limited | Information & communication | 2014 |
| Hurlock & Taylor Plumbing & Heating Engineers Ltd | Construction | 2007 |
| Hursley Rooms Ltd | Real estate | 2025 |
| Hursley Trading Limited | Manufacturing | 2020 |
| Hutber Homes Limited | Hospitality | 2018 |
| Hutton Surveying Ltd | Construction | 2022 |
| Huxley (UK) Limited | Other services | 1993 |
| Huxley Trustee Limited | Extraterritorial | 2020 |
| HWM Contracting Ltd | Administrative & support | 2010 |
| HWM Incorporated Limited | Administrative & support | 2010 |
| HWY Consulting Ltd | Professional & scientific | 2023 |
| Hyde Abbey Consulting Ltd | Professional & scientific | 2026 |
| Hyde Close Carpets & Flooring Ltd | Wholesale & retail | 2025 |
| Hyde Convenience Ltd | Wholesale & retail | 2018 |
| Hyde Laundry Management Ltd | Real estate | 2014 |
| HYDE900 Limited | Education | 2006 |
| Hydra Climate Change LLP | | 2005 |
| Hydrologic Solutions Limited | Professional & scientific | 2012 |
| Hydroscience Ltd | Professional & scientific | 2022 |
| Hyland Edgar Driver Limited | Professional & scientific | 1992 |
| Hyland Edgar Driver Trustees Limited | Administrative & support | 2019 |
| Hyphen Archi Ltd | Professional & scientific | 1992 |
| I Love Geeks Limited | Manufacturing | 2012 |
| I-Led (UK) Limited | Manufacturing | 2010 |
| I-Wonder Aggregator Services Limited | Information & communication | 2008 |
| I-Wonder Solutions Group Holdings Limited | Information & communication | 2017 |
| I.C.E. Events Hampshire Limited | Hospitality | 2018 |
| I.S. Simpson Electrical Installations Ltd | Construction | 1997 |
| I3 GEN Ltd | Professional & scientific | 2016 |
| IAC Cars Limited | Wholesale & retail | 2006 |
| IAN Johnston Associates Limited | Professional & scientific | 2014 |
| IAN Sharland Limited | Administrative & support | 1977 |
| IBI Analytics Ltd | Information & communication | 2023 |
| IBM Limited | Professional & scientific | 1980 |
| IBM UK Healthcare Trustee Limited | Administrative & support | 2016 |
| IBM United Kingdom Asset Leasing Limited | Administrative & support | 1975 |
| IBM United Kingdom Financial Services Limited | Financial services | 1975 |
| IBM United Kingdom Holdings Limited | Professional & scientific | 1912 |
| IBM United Kingdom Limited | Manufacturing | 1962 |
| IBM United Kingdom Pensions Trust Limited | Administrative & support | 1980 |
| Ice Cream Films Limited | Information & communication | 2020 |
| Icecool Trailers Limited | Administrative & support | 2012 |
| Icfo Services Limited | Financial services | 2016 |
| Icompassuk Limited | Education | 2020 |
| Idea Nova Ltd | Manufacturing | 2026 |
| Ideasage Ltd | Education | 2024 |
| Identical Limited | Manufacturing | 2014 |
| Idle Luxury Limited | Arts & recreation | 2000 |