| IB Property Commercial Investment UK Ltd | Real estate | 2022 |
| IB Property Investment (UK) Ltd | Real estate | 2012 |
| Ibarho Ltd | Information & communication | 2021 |
| Ibex Best Limited | Extraterritorial | 2015 |
| Ibex Builders Limited | Construction | 2010 |
| Ibex Construction Limited | Administrative & support | 2016 |
| IBO Barbers EN1 Ltd | Other services | 2024 |
| Ibrahim's Property Investment Limited | Real estate | 2023 |
| Ibrahims Consultancy Limited | Other services | 2024 |
| Ibuyplussell Ltd | Administrative & support | 2018 |
| Ibzy Ltd | Hospitality | 2021 |
| IC Housing Ltd | Real estate | 2026 |
| IC Nails and Lashes Ltd | Other services | 2022 |
| IC Unique Services Limited | Health & social care | 2013 |
| ICA Logistics Ltd | Transport & logistics | 2019 |
| ICC Crystal Clean Car Wash Ltd | Wholesale & retail | 2025 |
| Ice Creams Time Ltd | Hospitality | 2025 |
| Ice Ice Babie Ltd | Hospitality | 2024 |
| Icli Painting & Decoration Ltd | Construction | 2025 |
| ICO Roofing Ltd | Construction | 2022 |
| Icri Ltd | Real estate | 2004 |
| IDA Cleaning Services Ltd | Administrative & support | 2024 |
| Ideal Cruises Ltd | Administrative & support | 2025 |
| Ideal Glass E Limited | Construction | 2026 |
| Ideal Warren UK Ltd. | Information & communication | 2014 |
| IDI Plumbing Ltd | Construction | 2018 |
| Idia.Me Ltd | Administrative & support | 2021 |
| Idli Ltd | Professional & scientific | 2024 |
| Idowu Systems Ltd | Information & communication | 1998 |
| IDR Courier and Logistics Ltd | Transport & logistics | 2020 |
| Idrive Cars Ltd | Wholesale & retail | 2019 |
| Iebo GAN Marble and Granite Ltd | Construction | 2019 |
| IEP Consulting Ltd | Information & communication | 2013 |
| Ifetobi Ltd | Health & social care | 2010 |
| Ifex Limited | Health & social care | 2019 |
| Ifill Group Ltd | Construction | 2026 |
| Iftiin Educatioin Centre Ltd | Education | 2024 |
| IGB Technology Ltd | Information & communication | 2018 |
| Igcc Homes Limited | Real estate | 2026 |
| Igdt FIX Limited | Construction | 2019 |
| IGF Construct Ltd | Construction | 2023 |
| IGF Homes Ltd | Real estate | 2026 |
| IGL Hairdressing & Supplies Ltd | Other services | 2021 |
| Iglesia Cleaning Ltd | Administrative & support | 2026 |
| Ignat 26 Ltd | Administrative & support | 2026 |
| Ignis Catering Ltd | Hospitality | 2021 |
| IHO Engineering Ltd | Information & communication | 2018 |
| IKA Nation Ltd | Arts & recreation | 2026 |
| Ikigai Care Limited | Health & social care | 2025 |
| Ikoj Divine Services Ltd | Real estate | 2015 |
| Ikoyenia Violaris Group Ltd | Administrative & support | 2023 |
| IL3 Construction Ltd | Construction | 2026 |
| Ilay Consultancy Ltd | Wholesale & retail | 2023 |
| Ilays Community Limited | Education | 2017 |
| Ilberco Ltd | Wholesale & retail | 2026 |
| Ilia Trading Ltd | Construction | 2015 |
| Ilker Property Ltd | Real estate | 2025 |
| Illy & Sons Limited | Construction | 2025 |
| Illy Hair Ltd | Other services | 2025 |
| Imaan Holdings Limited | Real estate | 2026 |
| IMAGINE3D Ltd | Professional & scientific | 2011 |
| Imaj Hair Ltd | Other services | 2021 |
| Imani Waxes Ltd | Manufacturing | 2025 |
| IMC Developers Ltd | Construction | 2025 |
| IMD Painters Ltd | Construction | 2024 |
| Imgg. Ltd | Information & communication | 2026 |
| Immaculate Vibe Ltd | Information & communication | 2026 |
| Immediate Social Care Limited | Health & social care | 2010 |
| Immersive Travel Ltd | Information & communication | 2018 |
| Impact Media Marketing Solutions Ltd | Professional & scientific | 2024 |
| Impeccability Ltd | Wholesale & retail | 2025 |
| Imperial Ice Distribution Limited | Professional & scientific | 2018 |
| Imperial Stone UK Ltd | Construction | 2025 |
| Imperial UW Limited | Financial services | 2022 |
| Imperium (RH9 8LY) Ltd | Real estate | 2021 |
| Imperium Belfry Limited | Construction | 2024 |
| Imperium Homes Group Ltd | Real estate | 2017 |
| Imperium Scaffolding Ltd | Construction | 2026 |
| Impero Distribution Limited | Wholesale & retail | 2022 |
| Impervious Four Limited | Administrative & support | 2015 |
| Impervious Infrastructure Ltd | Real estate | 2022 |
| Impress Property Developments Ltd | Real estate | 2020 |
| Impressed London Services Ltd | Other services | 2023 |
| Improving Homes Ltd | Construction | 2025 |
| IN Consulting and Services Ltd | Professional & scientific | 2026 |
| IN Distribution Limited | Wholesale & retail | 2014 |
| IN Safe Hands Medical Centre Ltd | Health & social care | 2019 |
| IN the Village Ltd | Health & social care | 2022 |
| In-Tuition Networks Limited | Information & communication | 2002 |
| INA Customer Service Solutions Ltd | Administrative & support | 2021 |
| Inauratus Holdings LP | | 2017 |
| Inbrained Limited | Education | 2013 |
| Incesu Business Development Limited | Professional & scientific | 2022 |
| Inci Express Ltd | Wholesale & retail | 2018 |
| Incisilay Ltd | Wholesale & retail | 2025 |
| Incorporatetherapy Ltd | Health & social care | 2025 |
| Incrementally Ltd | Information & communication | 2018 |
| Independent Soundz CIC | Arts & recreation | 2026 |
| Indext Ltd | Information & communication | 2020 |
| Indiana Residence Ltd | Construction | 2024 |