| Howle Hotels Ltd | Hospitality | 2015 |
| Hpcm Limited | Professional & scientific | 2010 |
| HRH-7 Enterprises Ltd | Real estate | 2025 |
| HS Land and Farms Ltd | Agriculture & fishing | 2024 |
| HSE Electrical Limited | Construction | 2006 |
| HSE Professional Services Ltd | Professional & scientific | 2020 |
| HSW Media Ltd | Professional & scientific | 2022 |
| HT Support Ltd | Information & communication | 2015 |
| HTG Mortgages Limited | Financial services | 2024 |
| HTG Property Group Limited | Real estate | 2023 |
| HTM (UK) Limited | Administrative & support | 1991 |
| Htoo Ltd | Wholesale & retail | 2023 |
| Hubbl UK Limited | Professional & scientific | 2023 |
| Hudson Steel Ltd | Manufacturing | 2018 |
| Hues Farm Contracting Limited | Agriculture & fishing | 2010 |
| Hugh Davies & Co LIO Limited | Professional & scientific | 2018 |
| Hugh Davies Consulting Ltd | Professional & scientific | 2019 |
| Hughenden Manor (Salisbury) 2020 Management Company Limited | Households | 2020 |
| Hughes Legacy Holdings Limited | Hospitality | 2017 |
| Hughes Legacy Property Ltd | Real estate | 2020 |
| Hughes-Dolphin Property Company Limited | Real estate | 2024 |
| Hugo Bingham Limited | Information & communication | 2015 |
| Hulse House Management Company Limited | Households | 2016 |
| Human Aspects Ltd. | Professional & scientific | 2017 |
| Human Capital Squared Limited | Administrative & support | 2016 |
| Hunt Press Ltd | Information & communication | 2019 |
| Huntercombe Walk (Taplow) Management Company Limited | Households | 2022 |
| Huntington Corporation Ltd | Information & communication | 2021 |
| Huntley Agriculture Limited | Agriculture & fishing | 2011 |
| Hunts Pond Road (NO 2) Management Company Limited | Households | 2011 |
| Huntsec Protect Limited | Administrative & support | 2023 |
| Hurcott Paper Mills Limited | Extraterritorial | 1912 |
| Hursley Workrooms Limited | Manufacturing | 2015 |
| Hurst Financial Consultancy Limited | Financial services | 2005 |
| Hurtsend Ltd | Manufacturing | 2024 |
| Hutchings Brothers (PFL) Limited | Extraterritorial | 2022 |
| HYBO2 Ltd | Health & social care | 2021 |
| Hyde Copse (Marcham) Management Company Limited | Households | 2016 |
| Hyde Land Kinver Management Company Limited | Real estate | 2020 |
| Hydropower Solutions Limited | Financial services | 2018 |
| Hylton Road (180) Management Company Ltd | Real estate | 2014 |
| Hyne Building Solutions Limited | Construction | 2014 |
| Hyperlocal FYI Limited | Information & communication | 2022 |
| Hyperwash Exterior Cleaning Ltd | Administrative & support | 2024 |
| Hyperwash Ltd | Administrative & support | 2023 |
| Hypnos Health LLP | | 2024 |
| Hyxtec Ltd | Manufacturing | 2021 |
| I & R Estates Limited | Real estate | 2023 |
| I Hart Solutions Ltd | Administrative & support | 2024 |
| I Quarter Management Company Limited | Administrative & support | 2006 |
| I&I Fast Delivery Ltd | Transport & logistics | 2024 |
| I&S Starkins Limited | Professional & scientific | 2013 |
| I-Dynamics Solutions Ltd | Real estate | 2010 |
| I.B Plumbing & Heating Limited | Construction | 2003 |
| I.T. Trading UK Limited | Other services | 1999 |
| IAE Ventures Limited | Financial services | 2021 |
| Iahim Trans Limited | Transport & logistics | 2025 |
| IAN Callaghan Associates Limited | Professional & scientific | 2010 |
| IAN Sheekey Accountancy Limited | Professional & scientific | 2020 |
| IB Renovations Limited | Real estate | 2025 |
| IB Salisbury Ltd | Other services | 2022 |
| Ibexu UK Ltd. | Professional & scientific | 2021 |
| Ibrahim Properties Ltd | Real estate | 2024 |
| Icare Training Ltd | Professional & scientific | 2018 |
| Iceberg Seafoods Ltd | Wholesale & retail | 2019 |
| Icenta Controls Limited | Manufacturing | 2002 |
| ICF Design Ltd | Professional & scientific | 2024 |
| ID Property Portfolio Ltd | Real estate | 2025 |
| Ida-Tronic Ltd | Manufacturing | 2017 |
| Idac Solutions Limited | Manufacturing | 1983 |
| Idacs Ridge Holdings Limited | Financial services | 2021 |
| Ideal Solutions Group Ltd | Construction | 2022 |
| Ideapunks Ltd | Information & communication | 2025 |
| Idge Ltd | Construction | 2025 |
| Idol Optics UK Ltd | Manufacturing | 2023 |
| Iengineering Ltd | Professional & scientific | 2025 |
| IFG GRP UK Limited | Professional & scientific | 2016 |
| IFG UK Group Holdings Limited | Professional & scientific | 1998 |
| IFS ERP Consulting Ltd | Information & communication | 2015 |
| IFT Consultancy Ltd | Professional & scientific | 2016 |
| Ignite Insulation Limited | Professional & scientific | 2022 |
| Ignite Property Group Limited | Construction | 2021 |
| IHS Developments Limited | Administrative & support | 2014 |
| Ihtefaq Motors Ltd | Wholesale & retail | 2019 |
| IK Construction Management Limited | Administrative & support | 2013 |
| Ikon Ambulance Services Ltd | Health & social care | 2008 |
| IL Baretto UK Limited | Hospitality | 2024 |
| ILS Plus Ltd | Professional & scientific | 2019 |
| IM 1960 Limited | Professional & scientific | 2024 |
| IM Transport Ltd | Transport & logistics | 2018 |
| Imagic (UK) Limited | Information & communication | 1999 |
| Imagine This Early Years and Family CIC | Education | 2024 |
| IMB 1926 Limited | Real estate | 2017 |
| IMB 221 Limited | Real estate | 2026 |
| Immaculate Construction Ltd | Construction | 2011 |
| Immerse Agency Limited | Professional & scientific | 2015 |
| Immersive Group Gaming Ltd | Financial services | 2018 |
| Impact Martial Arts Ltd | Arts & recreation | 2019 |
| Impact Teachers Limited | Administrative & support | 2005 |
| Impeccableplumbing Ltd | Construction | 2024 |