| Hubbard Medical Services Ltd | Health & social care | 2014 |
| Hudson Conway (Gloucestershire) Limited | Professional & scientific | 2010 |
| Hudson Engineering Offshore Services Ltd | Administrative & support | 2018 |
| Hudson Fitton Crabbe Lavery Limited | Financial services | 2006 |
| Hudson Property Ltd | Real estate | 2018 |
| Huggins Property Company Limited | Real estate | 1978 |
| Hugh Blair Ltd | Construction | 2011 |
| Hugh Cullum Architects Limited | Professional & scientific | 2000 |
| Hugh Koch Associates LLP | | 2013 |
| Hughes & Co Racing Ltd | Arts & recreation | 2026 |
| Hughes & Co Sporting Ltd | Arts & recreation | 2026 |
| Hughes Inns Ltd | Hospitality | 2017 |
| Hughes Paddison Limited | Professional & scientific | 2010 |
| Huki Limited | Wholesale & retail | 2020 |
| Human Digital Thinking Ltd | Professional & scientific | 2010 |
| Human Risk Reduction Services Limited | Professional & scientific | 2018 |
| Humanideas Ltd | Administrative & support | 2025 |
| Humf Group Ltd | Wholesale & retail | 2025 |
| Hundr Ltd | Information & communication | 2017 |
| Hungry Cooks Kitchen Ltd | Information & communication | 2024 |
| Huni Limited | Wholesale & retail | 2007 |
| Hunscote | Professional & scientific | 2025 |
| Hunt's Vehicle Logistics Ltd | Transport & logistics | 2018 |
| Huntington Antiques Limited | Wholesale & retail | 1977 |
| Huntington House (Hldgs) Ltd | Health & social care | 2014 |
| Huntington House Limited | Health & social care | 1973 |
| Hunts Homes Glos Ltd | Real estate | 2021 |
| Huret Ltd | Real estate | 2019 |
| Hurricane 2.0 Limited | Financial services | 2018 |
| Hurst Park Dental Practice Limited | Health & social care | 2010 |
| HUT Products Ltd | Wholesale & retail | 2020 |
| Hutleys Wealth Ltd | Real estate | 2020 |
| Hutlog Ltd | Mining & quarrying | 2021 |
| Hutton Financial Management Limited | Financial services | 2010 |
| Hutton Village Dental Practice Limited | Health & social care | 2007 |
| Huuman Ltd | Health & social care | 2022 |
| HUW Group Ltd | Construction | 2024 |
| Huys Management Ltd | Hospitality | 2007 |
| Huzar Construction Ltd | Construction | 2016 |
| HVI Ltd | Wholesale & retail | 2021 |
| Hvml Ltd | Financial services | 2018 |
| Hwbp Limited | Hospitality | 2023 |
| Hwit. Creative Limited | Professional & scientific | 2020 |
| Hybrid Sports Ltd. | Wholesale & retail | 2015 |
| Hydros Exterior Cleaning Services Ltd | Administrative & support | 2026 |
| Hygeia U.K. Ltd. | Wholesale & retail | 1994 |
| Hyman Associates Limited | Financial services | 2014 |
| Hyman Developments Limited | Construction | 2020 |
| Hyman Estates Limited | Construction | 2009 |
| Hyman Investments Limited | Financial services | 2019 |
| Hymnsheet Limited | Professional & scientific | 2004 |
| Hypertribe Ltd | Arts & recreation | 2018 |
| Hypertribe Music Limited | Information & communication | 2022 |
| Hyspeed (CNC) Limited | Manufacturing | 1993 |
| Hyspeed Group Limited | Professional & scientific | 1999 |
| Hyspeed Manufacturing Limited | Manufacturing | 2003 |
| Hysteria Brands Ltd | Financial services | 2020 |
| Hössle Culture Ltd | Information & communication | 2025 |
| I & K Nasser Limited | Health & social care | 2019 |
| I & P Management Services Limited | Administrative & support | 2004 |
| I AM ME Global Community Interest Company | Education | 2019 |
| I D Lyburn Limited | Health & social care | 2012 |
| I H Building Chel Ltd | Construction | 2018 |
| I Love Icecream Ltd | Professional & scientific | 2014 |
| I M Harrod Ltd | Education | 2012 |
| I&M Security Limited | Administrative & support | 2016 |
| I. Stojanov & Sons Limited | Wholesale & retail | 1992 |
| I.& J.Holmes & Co.Limited | Agriculture & fishing | 1964 |
| I.B.R. Limited | Wholesale & retail | 1998 |
| I.R. Dancey Limited | Administrative & support | 2003 |
| I2I Holdings Limited | Administrative & support | 2018 |
| I2I Independent Recruitment Consultancy Limited | Administrative & support | 2008 |
| I2I Marketing Limited | Professional & scientific | 1999 |
| I2I Search and Selection Limited | Administrative & support | 2018 |
| I2SCS Holdings Ltd | Financial services | 2026 |
| I2SCS Ltd | Financial services | 2026 |
| I2SCS Property Group Ltd | Financial services | 2026 |
| IAG (Global) Ltd | Transport & logistics | 2014 |
| Iain Harper Consulting Ltd | Information & communication | 2025 |
| IAM the Victor LLP | | 2023 |
| IAN Greaves International Limited | Administrative & support | 2003 |
| IAN Kennedy Productions Ltd | Arts & recreation | 2015 |
| Iaqua Watercraft Ltd | Extraterritorial | 2023 |
| Ibidem Capital Limited | Information & communication | 2012 |
| Ibluebell Limited | Information & communication | 2021 |
| Ibstock Collective Limited | Financial services | 2025 |
| IC Fabrications Limited | Manufacturing | 2023 |
| IC Nest Estates Limited | Real estate | 2025 |
| IC Thinking Ltd | Professional & scientific | 2018 |
| Ican Hospitality Solutions Ltd | Hospitality | 2019 |
| Icarus Cybersecurity Consulting and Training Ltd | Information & communication | 2020 |
| Icarus Health Solutions Limited | Health & social care | 2011 |
| ICC (One) Limited | Construction | 1996 |
| ICC (Two) Limited | Professional & scientific | 1997 |
| Iceberg Associates LLP | | 2006 |
| Iceberg Investment Group Ltd | Administrative & support | 2022 |
| ICF 100 LLP | | 2025 |
| Icklebtl Ltd | Real estate | 2017 |
| Icklefrog Consulting Ltd | Hospitality | 2009 |
| Icomehome Ltd | Real estate | 2021 |