| Ifixtech Wallisdown Ltd | Information & communication | 2018 |
| Ifocusapp Ltd | Information & communication | 2026 |
| Iford Caravans Limited | Hospitality | 1960 |
| Ifweraise Ltd | Administrative & support | 2023 |
| IG Reinforcement Ltd | Construction | 2022 |
| IGA Group Limited | Professional & scientific | 2026 |
| Igale Holdings Ltd | Financial services | 2021 |
| Igale Limited | Information & communication | 2015 |
| Ignis Boiler Services Limited | Construction | 2016 |
| IGO Ventures Ltd | Energy | 2023 |
| IGS Aerostructures Ltd | Professional & scientific | 2018 |
| Ihbss Limited | Agriculture & fishing | 2013 |
| Ihtsham & Sulayman Ltd | Wholesale & retail | 2024 |
| Ijnr Ltd | Information & communication | 2026 |
| IJW Developments Limited | Construction | 2015 |
| IK Aesthetic Training Ltd | Education | 2026 |
| IK Nutrition Ltd | Wholesale & retail | 2025 |
| IK Power Tech Ltd | Construction | 2025 |
| Iknowvation Group Limited | Wholesale & retail | 2020 |
| Ikomex Ltd. | Wholesale & retail | 2014 |
| Ikonic Developments Group Ltd | Construction | 2025 |
| Ikonic Homes Holdings Limited | Real estate | 2025 |
| Ikonic Homes Limited | Real estate | 2018 |
| Ikonic Roofing Ltd | Construction | 2025 |
| Ikram Group of Industries Ltd | Wholesale & retail | 2026 |
| ILA Law Ltd | Professional & scientific | 2021 |
| Ilaria Rose Property Ltd | Real estate | 2026 |
| Ilex Court Freehold Limited | Households | 2016 |
| Illume Ventures Limited | Professional & scientific | 2023 |
| Illumineyelashes Ltd | Other services | 2020 |
| Ilrich Ltd | Education | 2026 |
| Ilux Design & Supply Ltd | Construction | 2011 |
| Ilux Inspection Ltd | Professional & scientific | 2014 |
| Ilya Parfums Limited | Manufacturing | 2021 |
| Imag Displays Limited | Administrative & support | 2013 |
| Image XL Limited | Administrative & support | 2004 |
| Imaginary Unit Ltd | Information & communication | 2021 |
| Imaginative Elements Ltd | Information & communication | 2025 |
| Imagine Entertainment Ltd | Administrative & support | 2024 |
| Imagine Worldwide Ltd | Information & communication | 2020 |
| Imberti Ltd | Professional & scientific | 2020 |
| Immaculate Chaos Limited | Arts & recreation | 2014 |
| Immerse Medical Training Ltd | Education | 2016 |
| Immortal INK (Bournemouth) Limited | Other services | 2010 |
| IMP Properties Ltd | Real estate | 2022 |
| IMP Transport Solutions Ltd | Transport & logistics | 2022 |
| Impact Box Co-Operative Limited | Information & communication | 2022 |
| Impacto Negocios Limited | Wholesale & retail | 2025 |
| Impactus Partners Ltd | Administrative & support | 2017 |
| Imperial Chambers Block Management Co Ltd | Real estate | 2020 |
| Imperial Court Management [Canford Cliffs] Limited | Other services | 1992 |
| Impremis Ltd. | Manufacturing | 2005 |
| Impresionante Ltd | Information & communication | 2021 |
| Imran Brothers Limited | Wholesale & retail | 2016 |
| Imran Properties Limited | Real estate | 2018 |
| IN Focus Media Limited | Information & communication | 2011 |
| IN the Event of Ltd | Information & communication | 2024 |
| IN1 Ltd | Manufacturing | 2020 |
| Inbodyamy Limited | Other services | 2025 |
| Incandescent INK Publishing Limited | Information & communication | 2024 |
| Ince Properties Limited | Real estate | 2022 |
| Incipisense Limited | Professional & scientific | 2026 |
| Inclusive Media Solutions Ltd | Information & communication | 2014 |
| Incom Composite Engineering UK Ltd | Manufacturing | 2010 |
| Indee Softworks Limited | Information & communication | 2014 |
| Independent Lift Consultants Ltd | Other services | 2020 |
| Independent Marine Services Limited | Professional & scientific | 2017 |
| Independent Surgery (UK) Limited | Health & social care | 2005 |
| Independent Taxation and Web Services Limited | Professional & scientific | 2018 |
| Indigo Chicken Limited | Information & communication | 2014 |
| Indigo Soul Wellness Ltd | Wholesale & retail | 2024 |
| Indo-Brit Retail Ltd | Wholesale & retail | 2013 |
| Indoor Air Quality Limited | Construction | 1992 |
| Indra's NET Holdings Ltd | Financial services | 2026 |
| Indus Engineering Services Limited | Professional & scientific | 2018 |
| Industrial Building Services (Poole) Limited | Construction | 2001 |
| Industrial Links Limited | Wholesale & retail | 1995 |
| Industrial Service Solutions Limited | Wholesale & retail | 2018 |
| INDUSTRY4 Ltd | Manufacturing | 2016 |
| Indy Signs Ltd | Professional & scientific | 2022 |
| Inecs Ltd | Manufacturing | 2019 |
| Infernity Media Ltd | Manufacturing | 2017 |
| INFIN8SHIFT Ltd | Information & communication | 2024 |
| Infini East Ltd | Information & communication | 2024 |
| Infinitairium Ltd | Information & communication | 2022 |
| Infinitairiuum.Global Ltd | Information & communication | 2022 |
| Infinitarium Ltd | Information & communication | 2022 |
| Infinitariuum.Net Ltd | Information & communication | 2022 |
| Infinite Ecommerce Ltd | Wholesale & retail | 2025 |
| Infinite Light Technology Ltd | Information & communication | 2017 |
| Infinite Living Limited | Health & social care | 2017 |
| Infinity Cricket Ltd | Wholesale & retail | 2022 |
| Infinity Entertainment Group Ltd | Education | 2023 |
| Infinity Holdings Group Limited | Wholesale & retail | 2023 |
| Infinitygrowth Consulting Ltd | Information & communication | 2023 |
| Infinityscale BR Limited | Wholesale & retail | 2025 |
| Infinovation Ltd | Professional & scientific | 2025 |
| Inflexion-Point Strategy Partners Limited | Professional & scientific | 2006 |
| Inflomax Ltd | Education | 2025 |
| Infoculture Limited | Information & communication | 2017 |