| Icon London Limited | Extraterritorial | 2011 |
| Iconastas Limited | Wholesale & retail | 2006 |
| Iconivo Ltd | Information & communication | 2023 |
| Iconsult Services Limited | Professional & scientific | 2019 |
| IDA MAY Ltd | Professional & scientific | 2023 |
| Idea Point Ltd | Wholesale & retail | 2026 |
| Idea Technologies Limited | Information & communication | 2021 |
| Ideal Accountants London Ltd | Professional & scientific | 2020 |
| Ideal Fireworks (Wholesale) Limited | Wholesale & retail | 2021 |
| Ideal IT Consulting Ltd | Information & communication | 2022 |
| Identity Link Limited | Information & communication | 2019 |
| Idigitalhub Limited | Information & communication | 2020 |
| IDK Dynamics Ltd | Professional & scientific | 2022 |
| IDM Analytics Limited | Professional & scientific | 2013 |
| IDM Software Limited | Information & communication | 2006 |
| IFC Training & Consulting Ltd | Education | 2019 |
| IFG Consult Ltd | Other services | 2014 |
| IFG Corporation Ltd | Other services | 2013 |
| Igency Media Ltd | Information & communication | 2019 |
| IGN Construction Ltd | Construction | 2020 |
| Iisdp (UK) Limited | Information & communication | 2006 |
| Iitechsolutions Ltd | Information & communication | 2025 |
| IJK Financial Solutions Limited | Financial services | 2015 |
| IK Estates Ltd | Real estate | 2011 |
| Ikash Ltd | Professional & scientific | 2010 |
| Ikmind Ltd | Health & social care | 2025 |
| Ikon 9 Ltd | Real estate | 2023 |
| Ilithyia Limited | Administrative & support | 2015 |
| Illuminati Solutions Ltd | Information & communication | 2016 |
| IM Property Maintenance Limited | Construction | 2015 |
| IM2 Building Approvers Ltd | Construction | 2025 |
| IM2 Limited | Construction | 2020 |
| IM2 Vault Ltd | Financial services | 2025 |
| Image Accounting and Tax Consulting Limited | Professional & scientific | 2020 |
| Imarainfinity Solutions Ltd | Information & communication | 2017 |
| Imed Pharma Limited | Health & social care | 2013 |
| Imedic Healthcare Supplies Ltd | Wholesale & retail | 2020 |
| IMP (Global) Limited | Education | 2005 |
| IMP IT Solutions Ltd | Information & communication | 2014 |
| IMP Smiles Ltd | Health & social care | 2025 |
| Impact Digital Media Ltd | Professional & scientific | 2016 |
| Impactflow Limited | Professional & scientific | 2020 |
| Impahla Property Investment Ltd | Real estate | 2019 |
| Impel Consult Limited | Professional & scientific | 2021 |
| Imperial Court Limited | Households | 1996 |
| Imperial Development (London) Limited | Construction | 2010 |
| Imperial Marble and Granite Limited | Manufacturing | 1999 |
| Imperial UK Cars Limited | Wholesale & retail | 2016 |
| Imperial World Technologies Ltd | Information & communication | 2013 |
| Impress Medical Limited | Health & social care | 2014 |
| Impro IM Limited | Administrative & support | 2010 |
| Impulse London Ltd | Administrative & support | 2017 |
| Imran Maan Ltd | Health & social care | 2012 |
| IMW Capital Limited | Financial services | 2019 |
| IN and OUT Food & Wine Limited | Wholesale & retail | 2013 |
| In-Tv Ltd | Administrative & support | 2015 |
| Inbrandgible Limited | Professional & scientific | 2011 |
| Incredible Escapes Ltd | Administrative & support | 2023 |
| Indago Vision Ltd | Health & social care | 2015 |
| Independent Advisory Solutions Limited | Professional & scientific | 1982 |
| Independent Social Work Limited | Health & social care | 2005 |
| Indian Tapas Ltd | Extraterritorial | 2017 |
| Indicola Beverages Ltd | Manufacturing | 2025 |
| Infinite Decor Ltd | Construction | 2014 |
| Infiniti Technology Limited | Wholesale & retail | 2026 |
| Infinity Pharma Ltd | Financial services | 2025 |
| Infiternal Asset Allianz Limited | Wholesale & retail | 2008 |
| Inflow Capital Investments Limited | Financial services | 2015 |
| Inflow Capital Management Limited | Financial services | 2025 |
| Inflow Capital Partners Limited | Financial services | 2026 |
| Inflow Capital Partners LP | | 2026 |
| Inflow Finance Group Limited | Financial services | 2026 |
| Inflow Private Finance Ltd | Financial services | 2015 |
| Inflow Property INV AB Limited | Financial services | 2026 |
| Inflow Property Investments Limited | Financial services | 2015 |
| Infologic PTY Limited | Extraterritorial | 2018 |
| Infologik Management Limited | Administrative & support | 2013 |
| Infotech Accountancy Limited | Professional & scientific | 2017 |
| Ingatestone Management Ltd | Information & communication | 2025 |
| Ingmi Limited | Information & communication | 2009 |
| Inherbal Ltd | Wholesale & retail | 2024 |
| Inicio Living Limited | Real estate | 2020 |
| Iniqwiti Ltd | Wholesale & retail | 2024 |
| INK and Frame Limited | Information & communication | 2016 |
| Inka Investments Limited | Real estate | 2019 |
| Inka Limited | Real estate | 1996 |
| Inkstone Books Ltd | Wholesale & retail | 2022 |
| Innomatics Infotech Limited | Information & communication | 2019 |
| Innovate Pharma Services Limited | Health & social care | 2015 |
| Innovatexperts Ltd | Information & communication | 2023 |
| Innovation Asset Protection Ltd | Professional & scientific | 2012 |
| Innovative Consultants Limited | Information & communication | 2022 |
| Innovative International Group Limited | Professional & scientific | 2008 |
| Innovative Khera Solutions Ltd | Information & communication | 2019 |
| Innovative Technological Systems Limited | Information & communication | 2014 |
| Innovera Limited | Information & communication | 2025 |
| Inovax Ltd | Manufacturing | 2025 |
| Inox Building Services Limited | Construction | 2026 |
| Insight AX Consulting Ltd | Information & communication | 2013 |
| Insight Financial Limited | Financial services | 2018 |