| Hutchings Enterprises Limited | Professional & scientific | 2019 |
| Hutchinson Chambers Ltd | Real estate | 2021 |
| Hutchinson Health Ltd | Health & social care | 2020 |
| Hutts Heating Ltd | Construction | 2020 |
| Huxley Developments Ltd | Construction | 2021 |
| HW Hants Limited | Hospitality | 2012 |
| HWG Building Limited | Construction | 2020 |
| Hyderabadi Dastarkhawna Ltd | Hospitality | 2026 |
| Hydrotrace Ltd | Construction | 2026 |
| Hyhaus Properties Ltd | Real estate | 2018 |
| Hyline Interiors Limited | Construction | 2008 |
| Hymers Groundworks & Construction Ltd | Construction | 2023 |
| Hymers Group Ltd | Construction | 2025 |
| Hytheorem Consulting Ltd | Construction | 2026 |
| Hyypa Ltd | Education | 2022 |
| I Care Services (PVT) Limited | Health & social care | 2014 |
| I GAS Engineers Plumbing & Heating Ltd | Construction | 2021 |
| I Love to Learn Professional Tuition (Fareham) Ltd | Extraterritorial | 2023 |
| I Moody Interiors Limited | Construction | 2016 |
| I Tech Care Industries Ltd | Administrative & support | 2023 |
| I&J Group Ltd | Wholesale & retail | 2019 |
| I-Connect Media Limited | Information & communication | 2026 |
| I-Layer Assist Ltd | Information & communication | 2008 |
| I.M.E Group Limited | Manufacturing | 2017 |
| I.M.E Repair Services Limited | Manufacturing | 2006 |
| I2I Group Ltd | Professional & scientific | 2021 |
| I:Two Management Company Limited | Households | 2004 |
| IAC Residential Ltd | Real estate | 2023 |
| Iacob Cargo Ltd | Transport & logistics | 2018 |
| IBD Solutions Limited | Construction | 2011 |
| IBM Limited Partnership | | 2001 |
| Ibrahim Wholesale Ltd | Wholesale & retail | 2016 |
| IC Lettings Ltd | Real estate | 2018 |
| Icarus Media Ltd | Professional & scientific | 2020 |
| Ice Retail Ltd | Wholesale & retail | 2024 |
| Icon Electronics Limited | Manufacturing | 2009 |
| Iconic Bricks Limited | Manufacturing | 2022 |
| ID PE & Sport Limited | Education | 2017 |
| ID Text Check.Com Limited | Administrative & support | 2011 |
| IDA Corp UK Limited | Professional & scientific | 2024 |
| IDA Property Southern Ltd | Real estate | 2026 |
| Ideal Escapes Limited | Real estate | 2026 |
| Ideal Estates Ltd | Real estate | 2024 |
| Idlewild Life Limited | Hospitality | 2019 |
| Idpe & Sport in the Community C.I.C. | Education | 2023 |
| IDR Safety Ltd | Professional & scientific | 2024 |
| IES Carpets & Flooring Ltd | Construction | 2025 |
| Iflip Limited | Arts & recreation | 2014 |
| IG Industries Limited | Financial services | 2018 |
| IGF (Southern) Ltd | Construction | 2024 |
| Igfranky Ltd | Wholesale & retail | 2025 |
| Iglu.Com Bidco Limited | Administrative & support | 2012 |
| Iglu.Com Holdco Limited | Administrative & support | 2012 |
| Iglu.Com Holidays Limited | Administrative & support | 2007 |
| Iglu.Com Limited | Administrative & support | 1998 |
| Iglu.Com Manco Limited | Administrative & support | 2012 |
| Iglu.Com Midco Limited | Administrative & support | 2012 |
| Iglu.Com Transport Limited | Administrative & support | 2008 |
| Iglu.Com Trustees Limited | Professional & scientific | 2010 |
| Iglufastnet Limited | Administrative & support | 2015 |
| Igneous Construction and Development Ltd | Construction | 2018 |
| Ignite Mechanical Services Ltd | Construction | 2023 |
| IH EOD Services Ltd | Other services | 2015 |
| Iheem Ltd | Extraterritorial | 2017 |
| IL Global Group Limited | Education | 2023 |
| Ilanex Ltd | Wholesale & retail | 2026 |
| ILE OBE Ltd | Manufacturing | 2023 |
| Ilighting Limited | Wholesale & retail | 2022 |
| Illicit Finance Consulting Ltd | Professional & scientific | 2019 |
| Illustrious Healthcare Solutions Limited | Manufacturing | 2020 |
| Im-Press Garment Printing Ltd | Manufacturing | 2022 |
| Imajj Consult Ltd | Information & communication | 2025 |
| Imamhost Ltd | Wholesale & retail | 2024 |
| Imersar Ltd | Information & communication | 2017 |
| IMF Transport Limited | Transport & logistics | 2022 |
| Imgo Limited | Information & communication | 2018 |
| Imjustevents Limited | Administrative & support | 2019 |
| Immerse Water Services Ltd | Professional & scientific | 2016 |
| Immigration Advice Point (UK) Ltd | Professional & scientific | 2022 |
| Imobiliare Group Limited | Construction | 2018 |
| Imon Construction Ltd | Construction | 2006 |
| Impellerton Limited | Information & communication | 2016 |
| Imperial Investments Southern Limited | Administrative & support | 2005 |
| Imperial Kitchens Limited | Wholesale & retail | 2015 |
| Imperial Voyage Limited | Transport & logistics | 2024 |
| Impreg (UK) Limited | Professional & scientific | 2021 |
| IMS Transport Ltd | Transport & logistics | 2022 |
| Imtech (PVT) Ltd | Professional & scientific | 2022 |
| Imuve Lettings Ltd | Real estate | 2016 |
| IN for a Penny Productions Ltd | Information & communication | 2019 |
| IN the Box Marketing Ltd | Professional & scientific | 2016 |
| In-Touch Kitchens Limited | Professional & scientific | 2007 |
| IN2SYNERGY (UK) Ltd | Administrative & support | 2021 |
| IN5 Group Ltd | Real estate | 2019 |
| IN5 Hythe Limited | Real estate | 2020 |
| IN5 Management Ltd | Financial services | 2018 |
| Inabern Limited | Other services | 2018 |
| Inani Customer Ltd | Professional & scientific | 2023 |
| Inc Living Ltd | Real estate | 2016 |
| Incaster Ltd | Real estate | 2021 |