| Holland Farming Ltd | Agriculture & fishing | 2024 |
| Hollowcombe Education LLP | | 2011 |
| Holtwood Stables Ltd | Administrative & support | 2023 |
| Home Counties Sporting (Southern) Ltd | Arts & recreation | 2018 |
| Home Design Impact Limited | Hospitality | 2008 |
| Home Farm Barns (Tidworth) NO1 Management Limited | Households | 2020 |
| Home Farm Close (Tidworth) Management Limited | Households | 2021 |
| Honpou SAI Limited | Professional & scientific | 2007 |
| Hoof Geek Limited | Professional & scientific | 2014 |
| Horizon Bookkeeping Ltd | Professional & scientific | 2018 |
| Horsebrook House Limited | Real estate | 2022 |
| House of Avondale Ltd | Construction | 2021 |
| HP Community Locum Limited | Wholesale & retail | 2024 |
| Hrtt Limited | Administrative & support | 2025 |
| Hscs Enterprises Limited | Wholesale & retail | 2025 |
| Humphries Haulage Limited | Transport & logistics | 2020 |
| Hungerford Arcade Limited | Manufacturing | 2002 |
| Hutt Vehicle Services Ltd | Wholesale & retail | 2025 |
| HUW Jenkins Consulting Limited | Information & communication | 2018 |
| Huxmor Holdings Limited | Financial services | 2024 |
| Huxmor Limited | Financial services | 2023 |
| Huzzbuzz Ltd | Financial services | 2021 |
| I AM Helen CIC | Education | 2025 |
| I.T. Repair Gurus Limited | Professional & scientific | 2013 |
| I.T.Q.C.A Limited | Professional & scientific | 2010 |
| IAN Curry Technical Services Limited | Manufacturing | 2007 |
| Ibis Packaging Solutions Limited | Wholesale & retail | 2006 |
| Ice Magic Rentals UK Limited | Administrative & support | 2008 |
| Ideal Flights & Holidays Ltd | Administrative & support | 2025 |
| Idlaz Limited | Professional & scientific | 2019 |
| Impacz Ltd | Administrative & support | 2024 |
| Impress Laundry Ltd | Other services | 2020 |
| INA Freight Ltd | Wholesale & retail | 2017 |
| Inca Home Moves Limited | Real estate | 2018 |
| Incredible Enterprises Limited | Professional & scientific | 2012 |
| Incremental Software Limited | Information & communication | 2011 |
| Indian Curry to Go Ltd. | Hospitality | 2017 |
| Indigoblue Ltd | Professional & scientific | 2020 |
| Industry Finance UK Limited | Financial services | 2008 |
| Infinity I.T. Systems Ltd | Extraterritorial | 2025 |
| Inkfluence Limited | Other services | 2023 |
| Inks Personalized Ltd | Wholesale & retail | 2019 |
| Innovo Algae Tech Stack Venture 1 Limited | Professional & scientific | 2024 |
| Innovo CSA Algae Technologies SPV Limited | Professional & scientific | 2025 |
| Innovo Energy Storage Solutions SPV Limited | Professional & scientific | 2025 |
| Innovo Fairness LLP | | 2011 |
| Innovo Finance Limited | Administrative & support | 2012 |
| Innovo Innovation Advanced Technologies Vehicle - IV3 Limited | Administrative & support | 2018 |
| Innovo Innovation Defence Group - IV1 Limited | Administrative & support | 2018 |
| Innovo Innovation Limited | Administrative & support | 2018 |
| Innovo Innovation Retail Group - IV2 Limited | Administrative & support | 2018 |
| Innovo IP Limited | Professional & scientific | 2011 |
| Innovo IV Holdings One Limited | Administrative & support | 2018 |
| Innovo JV Holdings Limited | Professional & scientific | 2022 |
| Innovo Myko Bio-Farm SPV Number 1 Limited | Professional & scientific | 2024 |
| Innovo NET Zero Limited | Professional & scientific | 2022 |
| Innovo Network Limited | Administrative & support | 2011 |
| Innovo Vdq-Nrg WASTE2VALUE SPV Number 1 Limited | Water & waste | 2025 |
| Insight & Impact Strategies Limited | Professional & scientific | 2018 |
| Instone Memorials LLP | | 2011 |
| Integra Partnership Ltd | Information & communication | 2006 |
| Integrated Cable Systems Limited | Construction | 2004 |
| Intelligent Channel Partnerships Limited | Professional & scientific | 2008 |
| Intelligent Display Solutions Limited | Extraterritorial | 2012 |
| Intelligent Embedded Solutions Limited | Extraterritorial | 2012 |
| Intelligent Group Solutions Limited | Manufacturing | 2001 |
| Intelligent LED Solutions Limited | Professional & scientific | 2008 |
| Interface (Wootton Bassett) Management Company Limited | Real estate | 1988 |
| Interstella Consultancy Ltd | Information & communication | 2018 |
| Into the Light U.K. Limited | Other services | 2019 |
| Irish Horses Imported Ltd | Wholesale & retail | 2020 |
| Irostrum Limited | Information & communication | 2012 |
| Island Exhibitions Limited | Construction | 2005 |
| ISM Publishing Ltd | Information & communication | 2024 |
| Isobel SMM Limited | Professional & scientific | 2025 |
| Istanbul Mete Barber Ltd | Other services | 2020 |
| Itomark Limited | Professional & scientific | 2016 |
| Itsasteeluk Limited | Wholesale & retail | 2024 |
| IVY Rose Consultancy Limited | Administrative & support | 2009 |
| Izzyacs Ltd | Professional & scientific | 2025 |
| J a C Decorations Limited | Construction | 2011 |
| J F Cash Flooring Ltd | Construction | 2015 |
| J Freemantle Limited | Construction | 2013 |
| J Huntley Limited | Other services | 2003 |
| J Roberts Carpentry Ltd | Construction | 2021 |
| J&J O'Neill Properties Ltd | Administrative & support | 2009 |
| J&R Tyres Ltd | Wholesale & retail | 2019 |
| J.C. & N.C. Ward Limited | Agriculture & fishing | 1960 |
| J2PS (Bristol) Ltd | Real estate | 2018 |
| Jabezfj Ltd | Wholesale & retail | 2024 |
| JAC Dawson Groundworks & Landscaping Limited | Construction | 2025 |
| Jacinth Real Estate Ltd | Real estate | 2023 |
| Jacob Cameron Engineering Limited | Professional & scientific | 2010 |
| Jacqui Hill Executive Support Services Ltd | Administrative & support | 2012 |
| Jacs Mini Coach Travel Ltd | Transport & logistics | 2007 |
| Jade Distributions Ltd. | Wholesale & retail | 2020 |
| Jalloh Associates Limited | Administrative & support | 2016 |
| James and James Design Limited | Professional & scientific | 2022 |
| James Claydon Services Limited | Construction | 2021 |
| James Morrison Golf Limited | Arts & recreation | 2010 |