| Hubco Ltd | Financial services | 2017 |
| Hubert Corporation Limited | Other services | 2016 |
| Hudams Ltd | Real estate | 2018 |
| Hudson Autos Limited | Wholesale & retail | 2022 |
| Hudson Management Services Ltd | Construction | 2025 |
| Hudsons (BCJ) Limited | Construction | 2017 |
| Huerue Ecom Ltd | Wholesale & retail | 2025 |
| Hughes Plane Ltd | Financial services | 2016 |
| Hughes Training Strategies Ltd | Professional & scientific | 2005 |
| Hugo Home Improvements Ltd | Construction | 2021 |
| Hull & Sons Ltd | Wholesale & retail | 2019 |
| Hullbridge Residents Company Limited | Households | 1979 |
| Huller & Cheese Residents Company Ltd | Real estate | 2016 |
| Human Touch Productions Limited | Arts & recreation | 2026 |
| HUMAN2HUMAN Limited | Professional & scientific | 2009 |
| Humans VS Retirement Ltd | Information & communication | 2025 |
| Hummingbird Mortgages Limited | Financial services | 2023 |
| Hummingbird Pilates & Yoga LLP | | 2013 |
| Humphreys Hall Limited | Real estate | 2025 |
| Hundven-Clements Ltd | Professional & scientific | 2011 |
| Hunt and Hannah Ltd | Real estate | 2022 |
| Hunt Property Limited | Real estate | 2021 |
| Hunter Bayfield Limited | Professional & scientific | 2012 |
| Hunter Brown Limited | Financial services | 2025 |
| Hunter Oliveira Limited | Construction | 2020 |
| Hunter Wade Limited | Administrative & support | 2012 |
| Huqqabar Ltd. | Manufacturing | 2022 |
| Hurricane Way Garage Limited | Wholesale & retail | 2023 |
| Hussain 1 Limited | Hospitality | 2019 |
| Hutch Logistics Ltd | Wholesale & retail | 2020 |
| Huto Trading Ltd | Financial services | 2013 |
| Hutton Fitness Limited | Arts & recreation | 2015 |
| Hutton Mount Limited | Households | 1957 |
| Hutton Toning Studio Limited | Arts & recreation | 2021 |
| HUW Williams Transport Consultancy Ltd | Professional & scientific | 2025 |
| Hvar Ltd | Hospitality | 2025 |
| Hvar Professional Services Limited | Professional & scientific | 2016 |
| HVP Tech Ltd | Information & communication | 2026 |
| HVS Consultancy Limited | Construction | 2017 |
| HXJ Cargo Limited | Transport & logistics | 2018 |
| Hybrid Ecology Limited | Professional & scientific | 2017 |
| Hybrid Fencing Limited | Extraterritorial | 2014 |
| Hydor AS (UK) Ltd | Financial services | 2006 |
| HYDR8TION Ltd | Wholesale & retail | 2025 |
| Hydrahose Service Limited | Manufacturing | 1988 |
| Hydramed Clinic Ltd | Health & social care | 2026 |
| Hydroguard Limited | Manufacturing | 2013 |
| Hydromain Ltd | Construction | 2019 |
| Hygiene Contracts Limited | Administrative & support | 2014 |
| Hygienic Coatings Limited | Construction | 1994 |
| Hylands Construction Company Limited | Construction | 1996 |
| Hylands Electrical Limited | Information & communication | 2000 |
| Hylands Surveying Limited | Professional & scientific | 2026 |
| Hypatia Partners Ltd | Financial services | 2018 |
| Hyperbaric & Medical Services Limited | Health & social care | 1994 |
| Hyperian Global Limited | Manufacturing | 2002 |
| Hyperlogik Limited | Information & communication | 2024 |
| HYPERSCALE1 Limited | Professional & scientific | 2022 |
| Hyperstream Limited | Information & communication | 2003 |
| Hyphenated Limited | Professional & scientific | 2025 |
| Hyran Ltd | Real estate | 2012 |
| H’S Bespoke Cakes Ltd | Manufacturing | 2023 |
| I & W Group Limited | Financial services | 2023 |
| I Blanco Ltd | Health & social care | 2021 |
| I Care Essex Limited | Health & social care | 2024 |
| I Love Sport Limited | Arts & recreation | 2022 |
| I V S Luxxe Interior Limited | Construction | 2026 |
| I Vanity Ltd | Wholesale & retail | 2026 |
| I&I Sushi Ventures Ltd | Hospitality | 2025 |
| I&V Scaffolding Services Ltd | Construction | 2022 |
| I'Anson Consultancy Limited | Professional & scientific | 2015 |
| I-C-Why Consulting Limited | Information & communication | 2008 |
| I17 Limited | Wholesale & retail | 2020 |
| IAC Refrigeration and Air Conditioning Limited | Construction | 1986 |
| IAG Healthcare Limited | Health & social care | 2023 |
| IAG International Limited | Professional & scientific | 1989 |
| Iamtangential Limited | Information & communication | 2015 |
| IAN Corbett Specialist Oral Surgeon Limited | Health & social care | 2020 |
| IAN Mckinnell Limited | Professional & scientific | 2012 |
| IAN Wallaker (Builders) Limited | Construction | 1996 |
| IAN Waller Ltd | Administrative & support | 2012 |
| Ibbystyles Ltd | Other services | 2018 |
| Ibiza Party Passport Ltd | Administrative & support | 2025 |
| IBP Properties Ltd | Real estate | 2025 |
| Ibreast Clinic Limited | Health & social care | 2026 |
| Ibreastbook Ltd | Administrative & support | 2026 |
| Ibrok Ltd | Wholesale & retail | 2013 |
| Ibuytrade Ltd | Extraterritorial | 2013 |
| IC Prime Logistics Ltd | Transport & logistics | 2026 |
| Icarus Electrical Ltd | Construction | 2025 |
| Icdetails UK Ltd | Administrative & support | 2026 |
| Ice Forge Ltd | Manufacturing | 2026 |
| Ice Warning Ltd | Health & social care | 2014 |
| Icex Computers Limited | Information & communication | 2005 |
| Icex Group Limited | Information & communication | 2016 |
| Icex Limited | Information & communication | 2002 |
| Ickenham Services Limited | Hospitality | 2024 |
| Iconic CEO Limited | Professional & scientific | 2019 |
| Iconico LOG Homes Limited | Construction | 2014 |
| ICS Independent Claims Services Limited | Professional & scientific | 2012 |