| Hifi Black Limited | Manufacturing | 2018 |
| High Beam Clean Team Ltd | Administrative & support | 2020 |
| High Beeches Construction Ltd | Construction | 2014 |
| High Brook Consulting Ltd | Information & communication | 2024 |
| Hilltops Management (Petersfield) Limited | Households | 1985 |
| Historic Automobiles Limited | Wholesale & retail | 2004 |
| Hitching Boxing Ltd | Extraterritorial | 2024 |
| Hobbs & ORR Projects Ltd | Construction | 2026 |
| Holidayz Ltd | Extraterritorial | 2015 |
| Holly Roberts Coaching Ltd | Administrative & support | 2025 |
| Hollywater Ltd | Professional & scientific | 2003 |
| Holstocks Construction Ltd | Construction | 2018 |
| Home-Start Butser | Health & social care | 2011 |
| Homelink International Limited | Other services | 1994 |
| Homes Estate Agents Holdings Limited | Financial services | 2024 |
| Homes Estate Agents Limited | Real estate | 2011 |
| Homes Estate Agents Sales Ltd | Real estate | 2025 |
| Homes Property Services & Estate Agents Limited | Real estate | 2011 |
| Hometown Empire Limited | Financial services | 2021 |
| Hometown Property Portfolio Limited | Real estate | 2020 |
| Horizon Records Limited | Wholesale & retail | 2004 |
| Hound Around Ltd | Other services | 2022 |
| Hounds for Heroes | Other services | 2010 |
| House Revival Ltd | Real estate | 2002 |
| HTF Construction Ltd | Construction | 2016 |
| Hubert Child Limited | Financial services | 2012 |
| Hucklefetch Ltd | Professional & scientific | 2000 |
| Huddart Consulting Limited | Information & communication | 2019 |
| Hudson Rental Properties Limited | Real estate | 2024 |
| Huntin Mart Ltd | Wholesale & retail | 2025 |
| Hunting Shooting Fishing Limited | Wholesale & retail | 2023 |
| Hustwick-Knight Limited | Real estate | 2022 |
| HUT & Hyde Limited | Construction | 2025 |
| HUW Waters Limited | Professional & scientific | 2015 |
| HUX Hospitality Ltd | Hospitality | 2025 |
| Hybrid Car Charge Limited | Energy | 2017 |
| Hyden Wood Management Company Limited | Water & waste | 2001 |
| Hydro Mine Limited | Professional & scientific | 2008 |
| Hydrotherapy Four Paws Ltd | Professional & scientific | 2015 |
| Hyperluminal Limited | Arts & recreation | 2012 |
| I Thrive Ltd | Wholesale & retail | 2010 |
| I'M After Ltd | Extraterritorial | 2017 |
| IAN Wightman Limited | Professional & scientific | 2020 |
| Ibco Investments Ltd | Real estate | 2021 |
| ICL Marketing Ltd | Administrative & support | 2020 |
| Icts Havant Ltd | Manufacturing | 2010 |
| Ideal Coachworks Ltd | Manufacturing | 2023 |
| Ideal Commercial Group Limited | Financial services | 2014 |
| Ideal Commercials Limited | Wholesale & retail | 2006 |
| ILP UK Holdings Ltd | Financial services | 2020 |
| Ilyse Ltd | Manufacturing | 2024 |
| Imax Systems Limited | Professional & scientific | 1995 |
| Immaculate Commercial Cleaning Ltd | Administrative & support | 2023 |
| Independent 4 Life Limited | Construction | 2007 |
| Independent Business Accounting Limited | Professional & scientific | 2004 |
| Independent Business Analysis Ltd | Professional & scientific | 2002 |
| Indo Professionals Limited | Administrative & support | 2019 |
| Indo Search Limited | Administrative & support | 2022 |
| Infinite Sky Solutions Ltd | Information & communication | 2021 |
| Infinity NET Media Limited | Information & communication | 2007 |
| Ingham Thomas Architects Ltd | Professional & scientific | 2020 |
| Inmans Property Limited | Real estate | 2022 |
| Innovative-Development Organisation Ltd | Professional & scientific | 2014 |
| Innovative-Group Organisation Ltd | Professional & scientific | 2014 |
| Innovative-Solution Organisation Ltd | Professional & scientific | 2014 |
| Inoto Ltd | Professional & scientific | 2018 |
| Inspection PIT Projects Ltd | Arts & recreation | 2026 |
| Inspired by Wood Ltd | Construction | 2024 |
| Install Aircon Limited | Construction | 2017 |
| Insync Technology Limited | Information & communication | 2003 |
| Insync Technology Trustees Limited | Administrative & support | 2022 |
| Integrated Veterinary Medicine Ltd | Professional & scientific | 2025 |
| Interior Collective Ltd | Financial services | 2018 |
| Interior LAB Group Ltd | Financial services | 2019 |
| Interior LAB Ltd. | Construction | 2013 |
| International Literary Properties UK Ltd | Financial services | 2020 |
| Interxbrl Ltd. | Professional & scientific | 2019 |
| Inventable Technologies Limited | Mining & quarrying | 2015 |
| Ironbark Consulting Ltd | Professional & scientific | 2026 |
| Isambard Systems Consultancy Ltd | Professional & scientific | 2016 |
| Island Residents Association Limited | Households | 1967 |
| Itinsite UK Limited | Information & communication | 2005 |
| Iusegenius Ltd | Professional & scientific | 2019 |
| Iver Car Park Limited | Construction | 2018 |
| IVY House Associates Limited | Other services | 2005 |
| J Hicks Holdings Limited | Professional & scientific | 2003 |
| J K Galleries Ltd. | Information & communication | 2001 |
| J L T Building Services Limited | Construction | 2019 |
| J Murphy Plastering Contractors Ltd | Professional & scientific | 2003 |
| Jackson Painting and Decorating Ltd | Construction | 2026 |
| Jake Joinery Ltd | Construction | 2020 |
| Jakob Bloch and Partners Ltd | Administrative & support | 1993 |
| Jamatt Management Limited | Professional & scientific | 2010 |
| James Edward Leoni-Peters Limited | Extraterritorial | 2025 |
| James Hall Estates Limited | Real estate | 2009 |
| James Jones Design Limited | Professional & scientific | 2015 |
| James Plant & Co Limited | Professional & scientific | 2010 |
| JC Business Group Ltd | Financial services | 2024 |
| JC Little Explorers Ltd | Health & social care | 2024 |
| JC Sports Online Ltd | Education | 2021 |