| Intelligent Team Ltd | Construction | 2023 |
| Inter Fit Ironmongery Ltd | Manufacturing | 2010 |
| Interactive Film Ltd | Arts & recreation | 2013 |
| Intercont Limited | Wholesale & retail | 2022 |
| Interfusion Glass Limited | Manufacturing | 2013 |
| Interfusion Joinery Ltd | Manufacturing | 2010 |
| Interiors With Style Limited | Manufacturing | 2013 |
| International Consortium of Scientific Research Ltd | Professional & scientific | 2016 |
| International Drilling Fluids Limited | Professional & scientific | 2014 |
| International E-Karate Organization Ltd | Arts & recreation | 2020 |
| International Economic Development Platform Ltd | Professional & scientific | 2023 |
| International Medical Studies Ltd | Education | 2022 |
| International Skills Education and Career Limited | Education | 2023 |
| Internetivo Ltd | Wholesale & retail | 2023 |
| Interzones Limited | Wholesale & retail | 2021 |
| Intrinna Limited | Administrative & support | 2022 |
| Invent Valley Limited | Information & communication | 2025 |
| Inverted Orange Ltd | Professional & scientific | 2008 |
| Invest N More Limited | Professional & scientific | 2023 |
| Investac Limited | Professional & scientific | 2024 |
| Investbysb Ltd | Professional & scientific | 2022 |
| Investinuk Ltd | Real estate | 2023 |
| INVESTINUK2 Ltd | Real estate | 2025 |
| Investone Capital Ltd | Financial services | 2018 |
| Invictus MMA Ltd | Arts & recreation | 2024 |
| Invisible Arts Collective LLP | | 2011 |
| Inwood Construction & Interiors Ltd | Construction | 2023 |
| Inza Group Ltd | Health & social care | 2021 |
| IOM Bulk 1 Ltd | Transport & logistics | 2020 |
| IOM Marine Admin Ltd | Administrative & support | 2020 |
| ION Estates Commercial Limited | Other services | 2015 |
| ION Estates Limited | Real estate | 2014 |
| Ionut Contractors Ltd | Construction | 2023 |
| Ionut Transport Service Ltd | Manufacturing | 2020 |
| IP Technology (UK) Ltd | Information & communication | 2014 |
| Ipanema BBQ Ltd | Hospitality | 2020 |
| IPD 91 UK Ltd | Administrative & support | 2017 |
| Iq-Skin and Laser Ltd | Health & social care | 2014 |
| Ique Properties Limited | Real estate | 2025 |
| IRA Construction Ltd | Construction | 2018 |
| Iraq Business Gateway Limited | Information & communication | 2014 |
| Iraq International News Agency Limited | Information & communication | 2022 |
| Iraq Radios and Televisions Union | Other services | 2021 |
| Iron Service Global UK Limited | Information & communication | 2017 |
| Iron Tower Engineering Limited | Professional & scientific | 2016 |
| Ironstack Limited | Information & communication | 2026 |
| Is&E Ltd | Information & communication | 2017 |
| ISB Tech Solutions Limited | Information & communication | 2019 |
| ISH Properties (UK) Limited | Administrative & support | 2006 |
| ISH Properties Limited | Administrative & support | 2006 |
| Ishan Logistics Limited | Transport & logistics | 2008 |
| Ishar Properties Ltd | Real estate | 2016 |
| Isheish Group Ltd | Financial services | 2025 |
| Isher Global Limited | Financial services | 2026 |
| Ishrosh Healthcare Ltd | Wholesale & retail | 2000 |
| Ishtar Gate Services Ltd | Professional & scientific | 2021 |
| Ishtar Hair Salon Limited | Other services | 2024 |
| Ishveen Supermarket Ltd | Wholesale & retail | 2015 |
| Islamic Human Rights Commission | Other services | 2003 |
| ISM London Limited | Transport & logistics | 2015 |
| Isra Consulting Ltd | Professional & scientific | 2014 |
| Israel Smart International Group Co., Ltd | Mining & quarrying | 2025 |
| Issam Group Limited | Financial services | 2019 |
| Issy UK Investments Ltd | Professional & scientific | 2023 |
| Istone Quartz Limited | Manufacturing | 2019 |
| IT Acountants Ltd | Professional & scientific | 2020 |
| IT Ahmad Family LLP | | 2018 |
| IT Architechture Limited | Information & communication | 1996 |
| IT Group and More Limited | Information & communication | 2019 |
| IT Horizons International Limited | Wholesale & retail | 2022 |
| IT Horizons Limited | Wholesale & retail | 2022 |
| IT Services Bietl Limited | Information & communication | 2013 |
| It-Ahmad Investments Ltd | Real estate | 2018 |
| Ital Coachworks Limited | Wholesale & retail | 2002 |
| Italian Builders Limited | Construction | 2018 |
| Italk Gold Limited | Wholesale & retail | 2011 |
| Italk Investments Ltd | Real estate | 2026 |
| Itasca Medical Ltd | Health & social care | 2024 |
| Iterhom Ltd | Information & communication | 2024 |
| Itestu Ltd | Transport & logistics | 2005 |
| ITH Properties International Limited | Hospitality | 2024 |
| Itistobe Ltd | Professional & scientific | 2026 |
| Itistobe Tax & Accounts Ltd | Professional & scientific | 2025 |
| Itlabs Services Ltd | Information & communication | 2018 |
| Itnhub Ltd | Information & communication | 2022 |
| Itskaliuk Ltd | Other services | 2022 |
| Itsolutionline Ltd | Administrative & support | 2016 |
| Ittechiez Ltd | Information & communication | 2026 |
| Iulia POP Mini Market Ltd | Wholesale & retail | 2025 |
| Iuliu Lakatos Ltd | Transport & logistics | 2023 |
| IV Season PVT Ltd | Wholesale & retail | 2019 |
| Iver Tavern Ltd | Hospitality | 2023 |
| Iviay Life Ltd | Wholesale & retail | 2025 |
| Ivlearn Consultancy Ltd | Education | 2024 |
| Ivory & Onyx Nails by Priya Limited | Other services | 2026 |
| Ivorybond Properties Limited | Real estate | 2026 |
| Ivtanchev Limited | Construction | 2017 |
| IVY Homes Developments (UK) Ltd | Construction | 2024 |
| IVY UK Management Ltd | Professional & scientific | 2024 |
| Iwashanycar Limited | Administrative & support | 2024 |