| Hunter Isobel Consulting Ltd | Real estate | 2015 |
| Hunter Properties Ltd | Real estate | 2014 |
| Hunter Sachs Limited | Wholesale & retail | 2015 |
| Hurrikane Vibes Limited | Information & communication | 2020 |
| Husk the Label Ltd | Wholesale & retail | 2022 |
| Huxley Barley MOW Limited | Real estate | 2025 |
| Huxley Development 1 (HD1) Limited | Real estate | 2024 |
| Huxley Development 2 (HD1) Limited | Real estate | 2024 |
| Huxley Development 3 (HD1) Limited | Real estate | 2024 |
| Huxley Development 4 (HD1) Limited | Real estate | 2025 |
| Huxley Development 5 (HD1) Limited | Real estate | 2025 |
| Huxley Development Partners Limited | Real estate | 2026 |
| Huxley Mayfair Ltd | Real estate | 2025 |
| Hydra Trading Ltd | Wholesale & retail | 2025 |
| Hygieia Safety Solutions Ltd | Professional & scientific | 2020 |
| Hyperdrive Systems Limited | Information & communication | 1998 |
| Hyperos Oneclick Limited | Information & communication | 1997 |
| HZ Consulting Group Ltd | Administrative & support | 2022 |
| HZW Operations Limited | Professional & scientific | 2021 |
| I & B Guarding Limited | Administrative & support | 2020 |
| I & D Real Estate Ltd | Real estate | 2019 |
| I AM Dedicated by Ulissesworld Limited | Arts & recreation | 2018 |
| I Beauty Service Ltd | Administrative & support | 2021 |
| I Dream of Deanie Limited | Arts & recreation | 2017 |
| I Pope Construction Ltd | Construction | 2016 |
| I Pope Properties Ltd | Real estate | 2019 |
| I Sopa Limited | Transport & logistics | 2019 |
| I.Lessman Limited | Real estate | 1948 |
| IA and Co International Ltd | Wholesale & retail | 2019 |
| Iadvance Ltd | Administrative & support | 2023 |
| IBC Holdings Ltd | Real estate | 2025 |
| IC Construction Solutions Ltd | Construction | 2025 |
| ICD London Ltd | Administrative & support | 2022 |
| Ice Impressions Limited | Hospitality | 1998 |
| Ice Properties & Leasing Ltd | Real estate | 2024 |
| Ichor Magma Associates Limited | Other services | 2000 |
| ICO Research Ltd | Information & communication | 2013 |
| Iconic Gyms Limited | Arts & recreation | 2018 |
| Iconic Properties Group Ltd | Real estate | 2020 |
| Iconsult Limited | Administrative & support | 2014 |
| ICR Pharm Limited | Health & social care | 2011 |
| Ideal Export UK Limited | Transport & logistics | 2007 |
| Ideate Partners Ltd | Professional & scientific | 2018 |
| Identify Recruitment Limited | Administrative & support | 2023 |
| Identity Hair Salon Limited | Other services | 1999 |
| IDS Investments Ltd | Real estate | 2018 |
| Idylle Beauty Studio Ltd | Other services | 2019 |
| Idzv Ltd | Professional & scientific | 2019 |
| IF NOT NOW Films Limited | Administrative & support | 2006 |
| IFA Enterprises Limited | Wholesale & retail | 2009 |
| Ifacemarketing Limited | Wholesale & retail | 2019 |
| Ifancydat Limited | Other services | 2018 |
| Ifancythat.Com Limited | Other services | 2022 |
| IG Construction 25 Ltd | Construction | 2025 |
| IGN Electrical Ltd | Construction | 2022 |
| Ignexus Ltd | Wholesale & retail | 2021 |
| Ignite Aesthetics Limited | Other services | 2026 |
| Ignite People & Culture Limited | Administrative & support | 2024 |
| IGO Compliance Limited | Professional & scientific | 2023 |
| Ikemba Design Consultancy Ltd | Professional & scientific | 2020 |
| IKL Consultants Ltd. | Professional & scientific | 2014 |
| IKL Tech Ltd | Information & communication | 2016 |
| Ikonia Ltd | Hospitality | 2018 |
| Ikyb Limited | Information & communication | 2013 |
| IL Mattino Ltd | Manufacturing | 2017 |
| IL Raysals Ltd | Wholesale & retail | 2024 |
| Ilchoti Ltd | Transport & logistics | 2017 |
| Ilmbridge Academy Ltd | Education | 2025 |
| Ilures Limited | Health & social care | 2018 |
| Imaan Investments London Limited | Real estate | 2022 |
| Imaginative Training and Development Limited | Administrative & support | 2003 |
| Imamul C Services Limited | Professional & scientific | 2015 |
| Imogen Belfield Ltd | Professional & scientific | 2015 |
| Impact 8 Ltd | Professional & scientific | 2024 |
| Impact Office Installations Limited | Administrative & support | 2017 |
| Imperial Building Solutions Limited | Administrative & support | 2014 |
| Imperial Development Holdings Limited | Real estate | 2016 |
| Imperial Heights Limited | Real estate | 2018 |
| Imperial Locksmith Limited | Other services | 2016 |
| Imperial Properties & Investments Ltd | Real estate | 2013 |
| IMS Investment Solutions Ltd | Real estate | 2024 |
| IN and OUT Locksmiths Ltd | Manufacturing | 2025 |
| Inclass Ltd | Information & communication | 2025 |
| Inclusive Pathways CIC | Health & social care | 2019 |
| Incor Property Limited | Real estate | 2019 |
| Incorplus Ltd | Information & communication | 2014 |
| Inde Site Services Limited | Construction | 2024 |
| Indigo Worldwide Limited | Wholesale & retail | 1998 |
| Indrex Ltd | Construction | 2026 |
| Industrial Applications Ltd | Professional & scientific | 2010 |
| Infini Bridal Ltd | Wholesale & retail | 2025 |
| Infinite Building Solutions Limited | Construction | 2013 |
| Infinite Entertainment Limited | Arts & recreation | 2017 |
| Infinite Leisure Limited | Arts & recreation | 2017 |
| Infinite Plumbing Solutions Ltd | Wholesale & retail | 2017 |
| Infinite Progress Ltd | Administrative & support | 2014 |
| Infinity (LV) Ltd | Administrative & support | 2024 |
| Infinity Homes Holdings Ltd | Administrative & support | 2022 |
| Infinity IT Consultancy Limited | Information & communication | 2010 |
| Infinity New Homes Ltd | Construction | 2020 |