| Hinds and Gabriel Housing Ltd | Real estate | 2019 |
| Hippolab Solutions Limited | Information & communication | 2025 |
| Historama Ltd | Information & communication | 2023 |
| HJB Holdings Limited | Financial services | 2019 |
| HNH Online Ltd | Wholesale & retail | 2016 |
| HOB Interiors Ltd | Administrative & support | 2015 |
| Holden Hardware (Imports) Limited | Wholesale & retail | 2011 |
| Holistic Living Home Care Ltd | Health & social care | 2025 |
| Holistic Transitioning Ltd | Professional & scientific | 2018 |
| Holly Court Management (Sutton) Limited | Households | 1973 |
| Holy Impetus Limited | Real estate | 2022 |
| Home & Away (UK) Ltd | Wholesale & retail | 2014 |
| Home Away Support Service Limited | Health & social care | 2024 |
| Home Improvement Maintenance Services Limited | Construction | 2025 |
| Home Republic Pro Ltd | Construction | 2020 |
| Homeaid Solutions Ltd | Wholesale & retail | 2025 |
| Homefield Care Ltd | Health & social care | 2017 |
| Homelis Capital Partners Ltd | Real estate | 2025 |
| Homely Care Homes Limited | Health & social care | 2013 |
| Homesphere Property Ltd | Real estate | 2020 |
| Hometown Rolls and Baguettes Limited | Hospitality | 2016 |
| Honeysuckle Court Management Limited | Households | 1974 |
| Honeysuckle Group Ltd | Health & social care | 2019 |
| Horizon Umbrella Holding Ltd | Professional & scientific | 2025 |
| Horton Tower Limited | Health & social care | 2007 |
| Horton-May Holdings Ltd | Professional & scientific | 2024 |
| Host Express Limited | Hospitality | 2022 |
| Host Guru Limited | Hospitality | 2019 |
| Host Hub Limited | Hospitality | 2019 |
| Hound Dog Barber Shop Limited | Other services | 2016 |
| House of Vogue UK Ltd | Wholesale & retail | 2018 |
| House Recruitment Limited | Administrative & support | 2009 |
| Housemagic Limited | Real estate | 2011 |
| Houseward Ltd | Real estate | 2026 |
| HPS Lift Services Ltd | Professional & scientific | 2022 |
| HRL Investments Limited | Professional & scientific | 2018 |
| HS Printing & Computing Ltd | Administrative & support | 2014 |
| HSL Property Services Ltd | Construction | 2013 |
| HT Global Limited | Arts & recreation | 2015 |
| HT Rayward Developments Ltd | Construction | 2025 |
| HU Concepts Limited | Information & communication | 2026 |
| Hub Services Ltd | Construction | 2026 |
| Hubfort Ltd | Transport & logistics | 2024 |
| Hughes London Ltd | Manufacturing | 2018 |
| Human ARC Ltd | Information & communication | 2026 |
| Human Assets Limited | Professional & scientific | 1986 |
| Human Vibe Productions Ltd | Arts & recreation | 2023 |
| Humanity Support AID Ltd | Professional & scientific | 2022 |
| Hungry Bear Holdings Ltd | Real estate | 2024 |
| Huron Homes Limited | Real estate | 2025 |
| Hygeia Consortium Limited | Other services | 2013 |
| Hyspeed Broadband Ltd | Information & communication | 2011 |
| I Smooth Ltd | Wholesale & retail | 2024 |
| I Squared Partners Limited | Real estate | 2019 |
| Iamham Ltd | Extraterritorial | 2023 |
| Iampowered Ltd | Health & social care | 2018 |
| IAN Carrau Ltd | Other services | 2007 |
| IAN Grundy Ltd | Education | 2014 |
| Iansai Limited | Health & social care | 2020 |
| IB FD Consultancy Limited | Professional & scientific | 2024 |
| Ibbs Fofanah Limited | Health & social care | 2013 |
| IBC Manco Limited | Real estate | 2016 |
| IBK Solutions Ltd | Financial services | 2026 |
| Ibudina Limited | Real estate | 2021 |
| ICM Connect Ltd | Transport & logistics | 2020 |
| Iconic Chauffeuring Limited | Transport & logistics | 2022 |
| Iconic Intelligence Ltd | Information & communication | 2025 |
| Iconixstars Ltd | Manufacturing | 2025 |
| Icvent Ltd | Construction | 2024 |
| Idea Global Ltd | Wholesale & retail | 2023 |
| Ideal Medical International Ltd | Professional & scientific | 2017 |
| Ideal Medical Solutions Ltd | Wholesale & retail | 2011 |
| Ideal Properties (Surrey) LLP | | 2023 |
| Ievents Cardiff Ltd | Real estate | 2014 |
| IFY Multimedia Ltd | Information & communication | 2022 |
| Ijaz Ahmad Store Ltd | Wholesale & retail | 2026 |
| Ikano Insight Ltd | Professional & scientific | 1999 |
| Ikon Residents Management Company Limited | Households | 2004 |
| Ildersly Property Services Ltd | Construction | 2019 |
| Ilgi Design Ltd | Professional & scientific | 2012 |
| IM Ahmad Limited | Real estate | 2020 |
| Imagino Cake's Ltd | Manufacturing | 2021 |
| Imformed Industrial Mineral Forums & Research Ltd | Information & communication | 2014 |
| IML Vehicle Solutions Ltd | Wholesale & retail | 2018 |
| Immune Boost Limited | Wholesale & retail | 2020 |
| Impact Explorers Ltd | Administrative & support | 2019 |
| Imperiaco Ltd | Professional & scientific | 2019 |
| Imrun's Kitchen Ltd | Hospitality | 2023 |
| IMW Project Ltd | Construction | 2023 |
| IN2SPACE Housing Ltd. | Construction | 2014 |
| Inari Limited | Financial services | 2017 |
| Independent Chemist Supplies Limited | Wholesale & retail | 2000 |
| Indigo Engineering Limited | Wholesale & retail | 2022 |
| Indomitable Lion Entertainment Ltd | Hospitality | 2021 |
| Indoor Air Aware Community Interest Company | Professional & scientific | 2025 |
| Industriam Management Consultancy Ltd | Professional & scientific | 2026 |
| Inex Revamp Limited | Construction | 2004 |
| Infinity Laser Cutting Ltd | Manufacturing | 2013 |
| Infinity Retail Limited | Wholesale & retail | 2026 |
| Infinity Stone London Ltd | Wholesale & retail | 2024 |