| HTS Group Limited | Administrative & support | 2015 |
| HTS P&E Services Limited | Administrative & support | 2021 |
| Httr Consultancy Ltd | Health & social care | 2021 |
| Huamaya Wellness Ltd | Manufacturing | 2025 |
| Hub and Spoke Harlow Community Interest Company | Manufacturing | 2011 |
| Hubbard Hall Rooms Ltd | Hospitality | 2021 |
| Huckleberry's Chicken Limited | Hospitality | 2010 |
| Hudson Wealth Capital Limited | Financial services | 2026 |
| Hugdon Ltd | Administrative & support | 2017 |
| Hugeforce Ltd | Construction | 2018 |
| Huisarts Ltd | Health & social care | 2021 |
| Huma Food Limited | Hospitality | 2015 |
| Humble Housing Services Limited | Real estate | 2020 |
| Humphreys Pipe Fabricators Limited | Manufacturing | 2021 |
| Hunt R8 Limited | Wholesale & retail | 2018 |
| Hunter & Co Properties Ltd | Real estate | 2025 |
| Hunter Lettings & Property Management Ltd | Real estate | 2007 |
| Hunter Meat and Wine Restaurant Limited | Hospitality | 2023 |
| Hunter Security & Cabling Solutions Ltd | Construction | 2019 |
| Hunter Vehicles Limited | Manufacturing | 2007 |
| Huntercombe Court Management Company Limited | Households | 2003 |
| Hunters Brook Ltd | Construction | 2024 |
| Hurricane Recovery Ltd | Transport & logistics | 2019 |
| Huschem Limited | Wholesale & retail | 2003 |
| Huseyin Sevim Property Ltd | Real estate | 2024 |
| Hussein Housing Ltd | Construction | 2025 |
| Hutton Court Freehold Limited | Households | 1990 |
| Hutton Court Residents Association Limited | Households | 1988 |
| Hybrid MD Limited | Education | 2021 |
| Hydra Fight Gear Ltd | Manufacturing | 2022 |
| Hydronic Plumbing &Heating Ltd | Construction | 2024 |
| Hydroworx Ltd | Administrative & support | 2025 |
| Hygrove Court Freehold Limited | Households | 2020 |
| Hype Dance Fitness Ltd | Arts & recreation | 2022 |
| Hyperbook Ltd | Information & communication | 2018 |
| Hypnotic Image Ltd | Administrative & support | 2016 |
| I Interior Fit-Out Limited | Construction | 2017 |
| I Scream and Shake Limited | Extraterritorial | 2015 |
| I Want to BE Publishing Limited | Information & communication | 2024 |
| I&A Construction Ltd | Construction | 2016 |
| I'M the Problem Ltd | Information & communication | 2024 |
| I.D Heating and Plumbing Limited | Manufacturing | 2023 |
| I.G Constructor Ltd | Construction | 2023 |
| I.M Paradise Homes Limited | Real estate | 2015 |
| I.R.B. Installations Ltd | Construction | 2011 |
| I.T.E.I Ltd | Hospitality | 2015 |
| IAN Wallis Design Limited | Arts & recreation | 2008 |
| IB Decorators Limited | Construction | 2022 |
| IB Health Care Ltd | Health & social care | 2025 |
| Ibbco Civil Engineering Ltd | Construction | 2017 |
| Ibrahim Bashar Limited | Health & social care | 2023 |
| Ibs&Abs Limited | Hospitality | 2021 |
| IC Cafe Ltd | Hospitality | 2024 |
| Icason Global Consult Ltd | Health & social care | 2021 |
| Ichimas Auto Ltd | Wholesale & retail | 2017 |
| Icomply Online Limited | Professional & scientific | 2008 |
| Iconstantin Trans Ltd | Construction | 2017 |
| Idallison Medical Services Limited | Health & social care | 2021 |
| Idealz Ltd | Wholesale & retail | 2018 |
| Ideas Plus | Administrative & support | 1992 |
| Idnoble Enterprises Limited | Professional & scientific | 2020 |
| Idrisu Company Limited | Information & communication | 2015 |
| Idtech Systems UK Ltd | Information & communication | 2023 |
| Ifea Limited | Real estate | 2019 |
| Ifeoluwa Awoniran Limited | Health & social care | 2024 |
| Ifjeerwinj Limited | Administrative & support | 2019 |
| Ifyglo Services Limited | Health & social care | 2017 |
| Ifza Trading (UK) Ltd | Professional & scientific | 2025 |
| IGB Electrical Group Ltd | Financial services | 2023 |
| Igbinadolor Company Ltd | Health & social care | 2025 |
| Igbo Community Cheshire and Merseyside Ltd | Other services | 2021 |
| Igbo Community Development Union Chelmsford, United Kingdom Ltd | Other services | 2022 |
| IGM Connect Ltd | Construction | 2020 |
| Ignite Business Development Limited | Professional & scientific | 2018 |
| Ignytive HR Ltd | Professional & scientific | 2020 |
| II VI III Ltd | Professional & scientific | 2026 |
| Ijeada Ltd | Health & social care | 2025 |
| IKE Engineering Limited | Construction | 2016 |
| IKE Properties Ltd | Real estate | 2020 |
| Ikella Limited | Health & social care | 2022 |
| IL Bacio One Ltd | Hospitality | 2025 |
| IL Carpentry Ltd | Construction | 2019 |
| Ilchev Trans Ltd | Transport & logistics | 2017 |
| Ile-Ife (House of Love) Limited | Hospitality | 2023 |
| Ilie Chindris Ltd | Construction | 2016 |
| Ilie&Co. Limited | Wholesale & retail | 2025 |
| ILS Electrical Installations Limited | Construction | 2004 |
| Ilvida Ltd | Construction | 2021 |
| Ilyas Fauzan Limited | Health & social care | 2019 |
| Iløki Limited | Transport & logistics | 2026 |
| IM Space Ltd | Administrative & support | 2017 |
| Image Clothings Limited | Wholesale & retail | 2014 |
| IMAGES4INTERIORS Limited | Professional & scientific | 2013 |
| Imagine Contemporary Portraits Limited | Professional & scientific | 2004 |
| Imaging Consulting Ltd | Information & communication | 2012 |
| Imaintenance Services Limited | Manufacturing | 2019 |
| Imix Technology Ltd | Manufacturing | 2024 |
| Imocare Ltd | Health & social care | 2026 |
| Impact Clothing Limited | Manufacturing | 2020 |
| Impact Planning Limited | Professional & scientific | 2025 |