| HUG Wealth Ltd | Professional & scientific | 2025 |
| Huha Ltd | Professional & scientific | 2018 |
| Huihua Trading Ltd | Wholesale & retail | 2015 |
| Hulme Farm Mews Management Company Limited | Households | 2003 |
| Human Dividend Limited | Professional & scientific | 2018 |
| Human Edge LAB Limited | Professional & scientific | 2023 |
| Human Security UK, Ltd. | Information & communication | 2018 |
| Humaniti Foundation Limited | Professional & scientific | 2025 |
| Hundred Holdings Limited | Financial services | 2024 |
| Hunger Marketing Limited | Professional & scientific | 2018 |
| Hunter Airworks Limited | Professional & scientific | 2023 |
| Hunters Lodge (Wilmslow) Management Company Limited | Households | 2001 |
| Hunters Pointe Lodge Sales Limited | Hospitality | 2015 |
| Hunts Hospitality Limited | Hospitality | 2019 |
| Huntsmere Construction Limited | Construction | 2016 |
| Hurcott Business Solutions Ltd | Information & communication | 2019 |
| HUS Developments Ltd | Construction | 2025 |
| Hushed Ltd | Information & communication | 2022 |
| Hussains and Sons (Lees RD) Ltd | Wholesale & retail | 2014 |
| Husse South Manchester Ltd | Wholesale & retail | 2025 |
| Hutson & Amro Print Limited | Administrative & support | 2007 |
| Huxley Technology Limited | Information & communication | 2022 |
| Huxter & Davy Ltd | Health & social care | 2023 |
| HV UK RF1 Investments Ltd | Financial services | 2025 |
| HVC Accountancy Limited | Professional & scientific | 2024 |
| Hvmt Limited | Professional & scientific | 2023 |
| HW + Consulting Solutions Limited | Administrative & support | 2022 |
| Hweb Wine Limited | Information & communication | 2023 |
| Hybaid Limited | Professional & scientific | 1986 |
| Hybrid Extensions (London) Ltd | Construction | 2024 |
| Hybrid IT Limited | Information & communication | 2012 |
| Hybrid Search Limited | Administrative & support | 2017 |
| Hybrid Yacht Performance Ltd | Arts & recreation | 2025 |
| Hyde & Seek Services Limited | Professional & scientific | 2022 |
| Hyderabadi Fusion Ltd | Hospitality | 2025 |
| Hylcroft Ltd | Real estate | 2019 |
| Hymek Homes Ltd | Real estate | 2026 |
| Hyperdynamics Limited | Administrative & support | 2010 |
| Hyperscience Europe Ltd | Administrative & support | 2019 |
| Hypertech IT Services Limited | Information & communication | 2023 |
| Hypotheken Limited | Financial services | 2025 |
| Hysa Investments Limited | Real estate | 2014 |
| I & E Installations Ltd | Construction | 2022 |
| I & P Property Management Limited | Real estate | 2017 |
| I - Care TW Limited | Wholesale & retail | 2022 |
| I AM James Limited | Professional & scientific | 2021 |
| I Fardous Pharma Limited | Health & social care | 2025 |
| I GOT IT Limited | Professional & scientific | 2019 |
| I H Gallagher Limited | Construction | 2013 |
| I Like Singing Ltd | Arts & recreation | 2023 |
| I Love Travel Ltd | Administrative & support | 2025 |
| I M Holmes Limited | Real estate | 2021 |
| I Multimedia Solutions Ltd | Wholesale & retail | 2000 |
| I SEE Smiles Ltd | Health & social care | 2024 |
| I T Global Trade Ltd | Transport & logistics | 2025 |
| I Want Plants (Hyvert) Limited | Wholesale & retail | 2020 |
| I&L IT Solutions Limited | Professional & scientific | 2018 |
| I-Ark Software Limited | Information & communication | 2012 |
| I-Connect Software Limited | Information & communication | 2001 |
| I-Flights & Travels Ltd | Administrative & support | 2019 |
| I.E. Developments (UK) Ltd | Real estate | 2006 |
| I.Q. (BIO.) Limited | Professional & scientific | 1980 |
| I2 Engineering Ltd | Information & communication | 2020 |
| I2 Global Consulting Limited | Professional & scientific | 2017 |
| I2 Global Investments Limited | Professional & scientific | 2025 |
| I85 Tech Limited | Administrative & support | 2017 |
| IAB Properties Ltd | Real estate | 2025 |
| Iacovou Consulting Ltd | Professional & scientific | 2012 |
| Iact Limited | Administrative & support | 2025 |
| Iain Quarrie Projects Ltd | Real estate | 2025 |
| IAM Consulting Services Ltd | Real estate | 2017 |
| IAM Pharma Limited | Health & social care | 2019 |
| IAN Bright Architects Limited | Professional & scientific | 2013 |
| IAN Hazley Limited | Wholesale & retail | 2002 |
| IAN Lloyd Events Limited | Wholesale & retail | 2004 |
| IAN Macklin Lettings Ltd | Real estate | 2012 |
| Ianb Associates Limited | Administrative & support | 2021 |
| IB LNG Consulting Limited | Professional & scientific | 2019 |
| IB3 Consulting Limited | Real estate | 2011 |
| Ibase Software Solutions PVT Limited | Information & communication | 2015 |
| Ibek Limited | Professional & scientific | 2024 |
| Iberris Official Ltd | Wholesale & retail | 2025 |
| Ibhero.Com Limited | Information & communication | 2014 |
| Iboutique Ltd | Health & social care | 2014 |
| Ibumix Ltd | Manufacturing | 2023 |
| Ibwild Ltd | Wholesale & retail | 2024 |
| Ice AID Ltd | Arts & recreation | 2016 |
| Icee Properties Ltd | Real estate | 2023 |
| Iclean Inc Limited | Administrative & support | 2018 |
| Icoffee - Rhyl Limited | Hospitality | 2019 |
| Icoffee - Selby Limited | Hospitality | 2019 |
| Icoffee - Tunstall Limited | Hospitality | 2019 |
| Icoffee Limited | Hospitality | 2008 |
| Icon 1 Holdco Limited | Financial services | 2020 |
| Icon 25 Ltd | Hospitality | 2018 |
| Icon 3 Holdco Limited | Financial services | 2020 |
| Icon 4 Holdco Limited | Financial services | 2020 |
| Iconic Global Ltd | Wholesale & retail | 2025 |
| Iconika Ltd | Information & communication | 2023 |
| Iconnica Ltd | Wholesale & retail | 2023 |