| House of Finance Ltd | Professional & scientific | 2020 |
| House Refinement Ltd | Construction | 2017 |
| HR Guardian Ltd | Real estate | 2015 |
| Hsddtek Limited | Manufacturing | 2019 |
| Hubb Real Estate Ltd | Real estate | 2025 |
| Hurstys Plumbing Services Ltd | Construction | 2026 |
| Hustle Health Ltd | Wholesale & retail | 2024 |
| Huysal Transport Ltd | Transport & logistics | 2023 |
| Hv/Lv Technical Services Limited | Professional & scientific | 2019 |
| Hybrid Circle Limited | Wholesale & retail | 2015 |
| Hybrid Homes Ltd | Administrative & support | 2019 |
| Hybrid Powergen Limited | Extraterritorial | 2016 |
| Hybrid Technology Systems Limited | Wholesale & retail | 2018 |
| HZ Carpentry & Construction Ltd | Construction | 2023 |
| I & F Property Management Ltd | Real estate | 2022 |
| I AM Organic Ltd | Wholesale & retail | 2016 |
| I Choose ME Fitness Limited | Health & social care | 2025 |
| I Clark Electrical Ltd | Construction | 2023 |
| I Give YOU Take Limited | Wholesale & retail | 2019 |
| I&M Barbers Limited | Other services | 2026 |
| I&O Barber Limited | Other services | 2026 |
| I.M.T. Plastering Limited | Construction | 2012 |
| ID Mixes Ltd | Information & communication | 2025 |
| ID OIL Ltd | Water & waste | 2026 |
| Iemove Ltd | Transport & logistics | 2026 |
| Ifog Ltd | Professional & scientific | 2019 |
| Ihlara Valley Ltd | Hospitality | 2018 |
| Ihlas UK Limited | Wholesale & retail | 2005 |
| Ikandi Dating Ltd | Information & communication | 2020 |
| IL Gardino Limited | Hospitality | 2025 |
| IL Piatto ORO Limited | Hospitality | 2025 |
| Ilianski Cleaning Services Ltd | Administrative & support | 2026 |
| ILK Parfum Ltd | Wholesale & retail | 2019 |
| Ilsjay Limited | Wholesale & retail | 2023 |
| IM Construction and Building Ltd | Construction | 2021 |
| Imacbi Venturelab Ltd | Professional & scientific | 2026 |
| Image Print (London) Limited | Manufacturing | 2004 |
| Imagination Products Limited | Extraterritorial | 2002 |
| Imagine Consultancy Solutions Ltd | Professional & scientific | 2025 |
| IMF Consultancy Ltd | Professional & scientific | 2024 |
| Immanuel Care Ltd | Health & social care | 2017 |
| Imperial LUX Autos Ltd | Wholesale & retail | 2026 |
| Imperial Star Construction Limited | Construction | 2025 |
| Impex Freight Services Limited | Transport & logistics | 1984 |
| Improve Interiors Limited | Construction | 2025 |
| IMS Building Solutions Ltd | Administrative & support | 2011 |
| IMU Capital Limited | Real estate | 2025 |
| IMU Entertainment Limited | Hospitality | 2025 |
| Ince Capital Ltd | Real estate | 2022 |
| Ince Enterprise Ltd | Real estate | 2023 |
| Ince Ltd | Other services | 2015 |
| Ince Property Ltd | Real estate | 2020 |
| Indian VEG Bhelpoori House Ltd | Hospitality | 2017 |
| Indooroo Limited | Health & social care | 2023 |
| Indowud Europe Limited | Wholesale & retail | 2026 |
| Industrial Disposal Limited | Construction | 2010 |
| Infinity Plus Limited | Other services | 2016 |
| Infinity Scaffolding Ltd | Construction | 2023 |
| Inflatacity Limited | Arts & recreation | 2023 |
| Ingage Training Ltd | Education | 2024 |
| Ingen Services Limited | Professional & scientific | 2021 |
| Ingram Group Limited | Manufacturing | 2021 |
| Ink&Toast Ltd | Professional & scientific | 2023 |
| Inner City Traffic Management Limited | Transport & logistics | 2011 |
| Innovini Limited | Information & communication | 2019 |
| Inox Metal Works Ltd | Other services | 2021 |
| Insight FD Solutions Ltd | Professional & scientific | 2019 |
| Inspiring Your Home Limited | Wholesale & retail | 2019 |
| Instant Swim Club Ltd | Arts & recreation | 2026 |
| Instant Swim Holdings Ltd | Financial services | 2026 |
| Instant Swim Ltd | Wholesale & retail | 2020 |
| Integrations Limited | Extraterritorial | 1997 |
| Integrity Domiciliary Care Services (Idcs) Limited | Health & social care | 2012 |
| Interior & Exterior Clean & Care Ltd | Administrative & support | 2025 |
| International Carpet Consultants Ltd | Professional & scientific | 2025 |
| Interstor Contracts Limited | Construction | 1999 |
| Iothic Ltd | Information & communication | 2017 |
| IP Automotive Solutions Limited | Professional & scientific | 2021 |
| IP31 Limited | Other services | 2007 |
| IPD Cleaning Ltd | Administrative & support | 2020 |
| Ironbridge Capital Ltd | Real estate | 2025 |
| Isaco Services Ltd | Construction | 2015 |
| Iskenderun Brasserie Limited | Hospitality | 2025 |
| Isla Rose Management Ltd | Real estate | 2024 |
| Isla Rose Properties Ltd | Real estate | 2024 |
| Islington Fish Limited | Wholesale & retail | 2025 |
| Isokodesign Limited | Professional & scientific | 2015 |
| Isos Catering Limited | Hospitality | 2025 |
| Istan Enterprises Ltd | Wholesale & retail | 2025 |
| Istan Global Trading Ltd | Wholesale & retail | 2025 |
| Istanbul Abbey Barber Ltd | Other services | 2025 |
| Isupply Cars Limited | Wholesale & retail | 2019 |
| Ivison Lane Entertainment Limited | Hospitality | 2025 |
| Ivyni Ltd | Wholesale & retail | 2018 |
| Ixtinction Productions Ltd | Information & communication | 2021 |
| Izali Properties Ltd | Real estate | 2021 |
| J & J Accountancy Limited | Professional & scientific | 2008 |
| J a Motors & Repairs Ltd | Wholesale & retail | 2018 |
| J Britton Consultancy Ltd | Professional & scientific | 2024 |
| J J Stenographers Limited | Public administration | 2014 |