| Hsil AM Management Ltd | Professional & scientific | 2025 |
| Hsil GS Limited | Administrative & support | 2026 |
| Hsurfacing Ltd | Construction | 2022 |
| Htbc Solutions Limited | Other services | 2012 |
| HTD Select Ltd | Wholesale & retail | 2024 |
| HTP Electrical Ltd | Construction | 2018 |
| HTS Case Ltd | Wholesale & retail | 2025 |
| Hub Catering Limited | Hospitality | 2021 |
| Hubbards Bespoke Kitchens Kent Ltd | Manufacturing | 2025 |
| Hubble Executive Travel Ltd | Administrative & support | 2024 |
| Hudson Contract Flooring Ltd | Wholesale & retail | 2021 |
| Hudson Watts Ltd | Agriculture & fishing | 2025 |
| Hudson-Peacock Investments Ltd | Real estate | 2015 |
| Hudson-Peacock LLP | | 2010 |
| Huggins Bromage Ferguson Limited | Administrative & support | 2014 |
| Hugh Lowe Farms Limited | Agriculture & fishing | 1990 |
| Hugo Pinto Ferreira Limited | Professional & scientific | 2010 |
| HUH. Ltd. | Wholesale & retail | 2011 |
| Human Dimension Consulting Limited | Professional & scientific | 2008 |
| Human Field Ltd | Administrative & support | 2020 |
| Human First Collective Limited | Information & communication | 2023 |
| Humidity Response Ltd | Water & waste | 2014 |
| Humidity Specialists Ltd | Energy | 2024 |
| Hummingbird PUB Company Limited | Hospitality | 2021 |
| Humor Street Art Ltd | Arts & recreation | 2022 |
| Hun-Box Ltd | Wholesale & retail | 2021 |
| Hundrive Haulage Ltd | Transport & logistics | 2016 |
| Hunnybow Ltd | Wholesale & retail | 2024 |
| Hunt Management Limited | Other services | 1998 |
| Hunter and ELK Ltd | Construction | 2019 |
| Hunter Law Limited | Professional & scientific | 2016 |
| Hunters Bait Services Limited | Wholesale & retail | 2025 |
| Hunters Health Limited | Wholesale & retail | 2026 |
| Hunton Spirit Limited | Manufacturing | 2019 |
| Hurlingham Media Limited | Information & communication | 2005 |
| Hurst Hill (London) Ltd | Professional & scientific | 2014 |
| Husbem Homes Limited | Hospitality | 2025 |
| Hutt Imports Limited | Wholesale & retail | 2007 |
| HVS Business Services Ltd | Professional & scientific | 2020 |
| HVS Property Rentals Ltd | Real estate | 2025 |
| HW Transport Services Ltd | Transport & logistics | 2025 |
| HX Motors Limited | Professional & scientific | 2013 |
| Hybrid Boats Ltd | Professional & scientific | 2022 |
| Hybrid Innovation Agro Ltd | Wholesale & retail | 2023 |
| Hydes Property Services Limited | Professional & scientific | 2012 |
| Hydetech Ltd | Real estate | 2025 |
| Hyland Electrical Services Ltd | Construction | 2015 |
| Hynvest Ltd | Real estate | 2021 |
| Hyperion Energy Limited | Construction | 2022 |
| Hyperion Lands LLP | | 2008 |
| I DO Bars Ltd | Hospitality | 2025 |
| I Fruit Ltd | Agriculture & fishing | 2013 |
| I Love Marketing Ltd | Wholesale & retail | 2025 |
| I Petkov Ltd | Administrative & support | 2016 |
| I R Cawley (Holdings) Limited | Households | 2012 |
| I Track Direct Limited | Administrative & support | 2019 |
| I Want 2 BE Ltd | Wholesale & retail | 2025 |
| I&A Couriers Limited | Transport & logistics | 2024 |
| I&A Opus Ltd | Transport & logistics | 2015 |
| I&S Venture Ltd | Information & communication | 2022 |
| I&T Group Ltd | Construction | 2025 |
| I'Ll BE Mother Limited | Financial services | 2013 |
| I-Hv Investments Limited | Financial services | 2022 |
| I-Hv Limited | Energy | 2019 |
| I-Prove ESG Ltd | Professional & scientific | 2024 |
| I-Three Management Consulting Ltd | Professional & scientific | 2010 |
| I.R & P.J Brooker Limited | Construction | 2004 |
| I2 Consulting (UK) Ltd | Professional & scientific | 2006 |
| I2 Investments Limited | Real estate | 2007 |
| I2C Sport Media Limited | Professional & scientific | 2013 |
| IA Care UK Ltd | Health & social care | 2025 |
| Iaaaa Housing Ltd | Real estate | 2026 |
| Iacm for Counselling and Education Ltd | Education | 2022 |
| IAN Martin Carpentry & Building Services Ltd | Construction | 2011 |
| Ianzhula Ltd | Construction | 2022 |
| IAQ Venture Ltd | Information & communication | 2025 |
| IB Build Ltd | Construction | 2021 |
| IB Vehicle Hire Ltd | Transport & logistics | 2026 |
| Ibanez Investment Ltd | Financial services | 2025 |
| Ibasel Ltd | Transport & logistics | 2025 |
| Iben+Milo Limited | Wholesale & retail | 2017 |
| Ibex Compliance LLP | | 2023 |
| Ibex Developments Limited | Real estate | 2014 |
| Ibis Estates Ltd | Real estate | 2022 |
| Ibis Stores Ltd | Wholesale & retail | 2022 |
| IC & T Engineering Services Limited | Professional & scientific | 2010 |
| IC Environmental Limited | Extraterritorial | 2021 |
| Ice Asset Management Ltd | Professional & scientific | 2019 |
| Icebird Design Limited | Professional & scientific | 2024 |
| Icehot Limited | Wholesale & retail | 2017 |
| Iceland Seafood Barraclough Ltd | Wholesale & retail | 1980 |
| Icon Foods Ltd | Wholesale & retail | 2022 |
| ICS Chimney Sweeping Group Limited | Other services | 2017 |
| ICS Maintenance Limited | Extraterritorial | 2011 |
| ICS Psychotherapy Consultancy Ltd | Professional & scientific | 2023 |
| ID Contracts Limited | Construction | 2024 |
| ID Refurbs Ltd | Construction | 2022 |
| Idas Trans Ltd | Transport & logistics | 2022 |
| IDB Automotive Ltd | Wholesale & retail | 2019 |
| IDB Topman Ltd | Construction | 2023 |