| Houlton Property Investments Limited | Real estate | 2018 |
| House of Granite & Marble Limited | Construction | 2006 |
| House of T.O.B Limited | Construction | 2013 |
| House Proud Cleaning Services Walton Ltd | Administrative & support | 2020 |
| HOW Dairy Engineering Ltd | Manufacturing | 2026 |
| Howard Groves Acma Ltd | Professional & scientific | 2011 |
| Howson Building Renovations Ltd | Construction | 2023 |
| HP General Partner Limited | Real estate | 2000 |
| HP Hotels Limited | Hospitality | 2013 |
| HP Rentals Limited | Extraterritorial | 1999 |
| HP Rings Ltd | Transport & logistics | 2007 |
| HP Stores Ltd | Wholesale & retail | 2026 |
| Hpconsulting Services Limited | Manufacturing | 1994 |
| Hpgp 1 Limited | Professional & scientific | 2005 |
| Hpgp 2 Limited | Professional & scientific | 2005 |
| HQ Project Consulting Ltd | Construction | 2026 |
| HR Essentials Limited | Administrative & support | 2003 |
| HR Essentials Trust Limited | Professional & scientific | 2021 |
| HR in Business Excellence Ltd | Administrative & support | 2025 |
| HR Strategic Design Limited | Professional & scientific | 2021 |
| HRC Utilities Ltd | Construction | 2015 |
| HRE Newco Limited | Financial services | 2016 |
| HRL Properties Limited | Real estate | 2018 |
| HRS Contractors Ltd | Other services | 2020 |
| HS1521 Ltd | Hospitality | 2026 |
| HSP Stores Limited | Wholesale & retail | 2024 |
| HTH Matlock Limited | Hospitality | 2019 |
| HTK Lettings Ltd | Construction | 2022 |
| HTK Property Investments Limited | Real estate | 2022 |
| HTP (NO.1) Limited | Professional & scientific | 2007 |
| Huang Ying Takeaway Limited | Hospitality | 2017 |
| Hub Engineering Site Services Ltd | Professional & scientific | 2024 |
| Hubaco Holdings Limited | Financial services | 2021 |
| Hubaco Ltd | Professional & scientific | 2000 |
| Hubaco Trustees Limited | Financial services | 2021 |
| Hubbuck Construction Ltd | Construction | 2020 |
| Hubwaste Limited | Water & waste | 2021 |
| Hudfix Ltd | Manufacturing | 2025 |
| Hudson & Porter Ltd | Wholesale & retail | 2023 |
| Hudson Accountancy and Bookkeeping Services Limited | Professional & scientific | 2016 |
| Hugh Bankier Limited | Information & communication | 2007 |
| Hulse Properties Limited | Real estate | 2021 |
| Humblhaus Ltd | Professional & scientific | 2012 |
| Hunger Hill Farm Limited | Extraterritorial | 2025 |
| Hunger's Villa Ltd | Hospitality | 2026 |
| Hunter Communication Services (South) Limited | Information & communication | 2017 |
| Hunter Global Solutions Ltd | Information & communication | 2018 |
| Hunter Group Global Limited | Information & communication | 2017 |
| Hunters National Limited | Administrative & support | 2025 |
| Hutchings Decorating Limited | Construction | 2025 |
| Hutchinson's PVC Solutions Limited | Manufacturing | 2008 |
| Hutchinson's Spray Booths Limited | Manufacturing | 2024 |
| Hutton and Sons Ltd | Wholesale & retail | 2015 |
| Hutton Ward Limited | Real estate | 2003 |
| HWS Evesham Care Ltd | Health & social care | 2026 |
| Hydraulic Equipment Limited | Manufacturing | 2020 |
| Hydro Electrique Marine UK Limited | Professional & scientific | 2015 |
| Hydro Haus Limited | Wholesale & retail | 2026 |
| Hygge Products Limited | Manufacturing | 2016 |
| Hyperloop Transport Limited | Transport & logistics | 2021 |
| Hypesys Systems Ltd | Professional & scientific | 2022 |
| Hyraa Limited | Transport & logistics | 2021 |
| I B Electrical Maintenance Ltd | Construction | 2019 |
| I Love Hair Limited | Other services | 2010 |
| I Ojikutu Ltd | Information & communication | 2018 |
| I P Commercial Solutions Limited | Professional & scientific | 2002 |
| I P G Consultants Limited | Real estate | 2019 |
| I Want Pet Foods Ltd | Wholesale & retail | 2012 |
| I-Class Solutions Ltd | Information & communication | 2006 |
| I-Or Impressions Ltd | Manufacturing | 2024 |
| I.G. Tax Solutions Limited | Professional & scientific | 2020 |
| I.Grunwerg Limited | Wholesale & retail | 1954 |
| I.R. Construction Group Ltd | Construction | 2026 |
| I.R. Waste Management Ltd | Water & waste | 2010 |
| I.T. Needs Limited | Information & communication | 1996 |
| I.T.C Services (UK) Ltd | Professional & scientific | 2006 |
| I.W. Global Services Limited | Real estate | 2021 |
| IAN Booker Limited | Financial services | 2004 |
| IAN Jolley Limited | Wholesale & retail | 2009 |
| IAN Moore Kitchens Ltd | Manufacturing | 2008 |
| IAN Trueman Specialist Tree Services Limited | Agriculture & fishing | 2006 |
| Ianmenary Ltd | Professional & scientific | 2019 |
| Ibzy Salon Ltd | Other services | 2021 |
| Ic&T Solutions Limited | Other services | 2022 |
| IC3 Autos Ltd | Wholesale & retail | 2025 |
| Ican Accountants Private Limited | Professional & scientific | 2020 |
| Ice Drive Sweden Limited | Education | 2023 |
| ICJ Welding Services Limited | Transport & logistics | 2014 |
| ICM Investments Ltd | Real estate | 2025 |
| Icon Accounting Limited | Professional & scientific | 2022 |
| Icon Process Systems Limited | Manufacturing | 1999 |
| Iconic Photography Ltd | Other services | 2020 |
| ICOP1 Limited | Financial services | 2022 |
| ICOP2 LLP | | 2015 |
| Icot Limited | Professional & scientific | 2021 |
| ICS Fabrications Ltd | Manufacturing | 1999 |
| ID Fit Ltd | Arts & recreation | 2017 |
| Ideal Carpets of Chesterfield Limited | Wholesale & retail | 2011 |
| Ideal Connections Ltd | Professional & scientific | 2021 |
| Ideal Doors (2020) Ltd | Wholesale & retail | 2020 |