| ICG Prepress (UK) Ltd | Professional & scientific | 2003 |
| ICL Investment Group Limited | Financial services | 2024 |
| ICO Didsbury Limited | Construction | 2005 |
| Iconic Investments (GB) Limited | Administrative & support | 2008 |
| ICS (2035) Limited | Professional & scientific | 2007 |
| Ideal Gardening & Maintenance Ltd | Professional & scientific | 2022 |
| Ideal Home Interiors Ltd | Wholesale & retail | 2012 |
| Ideal Plumbing & Heating Installations Ltd | Construction | 2013 |
| Ideal Residence Ltd | Real estate | 2021 |
| Ideal Supported Living Ltd | Health & social care | 2018 |
| Ideal Tree Services Ltd | Administrative & support | 2021 |
| Idem Capital Holdings Limited | Financial services | 2011 |
| Idem Capital Securities Limited | Financial services | 2010 |
| Idoeverything Ltd | Information & communication | 2024 |
| Iepc Ltd | Professional & scientific | 2019 |
| Iepc Properties Limited | Real estate | 2025 |
| IFA Admin Solutions Limited | Administrative & support | 2013 |
| IFS Legal Services Limited | Professional & scientific | 2014 |
| Ignis Fire Protection Group Limited | Financial services | 2019 |
| Ignis Fire Protection Services Limited | Manufacturing | 2012 |
| Ignite Golf Limited | Education | 2021 |
| Ihabzorrito Ltd | Construction | 2024 |
| IHB Consulting Ltd | Information & communication | 2001 |
| Iidy Homes Limited | Real estate | 2020 |
| Ijezie Medical Services Ltd | Health & social care | 2021 |
| IJH Hvac Solutions Limited | Construction | 2020 |
| IK Engineering Projects Ltd | Professional & scientific | 2023 |
| IKA Consultancy Services Limited | Health & social care | 2016 |
| Ikaroa Limited | Administrative & support | 2020 |
| IKB Smile Specialists Ltd | Health & social care | 2023 |
| Ikon Brands Ltd | Manufacturing | 2018 |
| Ikoyi Medical Supplies Ltd | Wholesale & retail | 2025 |
| IKS (Midlands) Limited | Real estate | 2022 |
| IKT Consultancy Ltd | Professional & scientific | 2023 |
| Ikuto Group Ltd | Information & communication | 2020 |
| IL Sarto Ltd | Wholesale & retail | 2022 |
| Ilamp Africa Ltd | Financial services | 2016 |
| Ilford Court Management (Coventry) Limited | Households | 1966 |
| Ilhaam Holdings Limited | Real estate | 2021 |
| Ilinco Ltd | Transport & logistics | 2018 |
| ILO Capital Ltd | Administrative & support | 2016 |
| Iloac Limited | Financial services | 2019 |
| Ilocx Limited | Financial services | 2017 |
| Ilomx Limited | Information & communication | 2020 |
| Ilou Limited | Education | 2019 |
| IM Land 1 Limited | Real estate | 2016 |
| IM Land 2 Limited | Real estate | 2015 |
| IM Land 3 Limited | Real estate | 2016 |
| IM Land 4 Limited | Real estate | 2016 |
| IM Properties (BVP 3) Limited | Real estate | 2016 |
| IM Properties Bridgnorth Limited | Real estate | 2022 |
| IM Properties Hemel Limited | Real estate | 2022 |
| IM Properties Hinckley Limited | Real estate | 2022 |
| IM Properties Residential Group Limited | Financial services | 2021 |
| IM Property Developments Limited | Real estate | 2020 |
| IM Well Ltd. | Health & social care | 2016 |
| Imaan Properties (Midlands) Limited | Real estate | 2024 |
| Imaarmep Ltd | Professional & scientific | 2026 |
| Imaestri Bohemian Ltd | Construction | 2019 |
| Imaestri Signature Ltd | Construction | 2015 |
| Imaestri Yacht Ltd | Wholesale & retail | 2018 |
| Image New Limited | Administrative & support | 2006 |
| Imagegold Limited | Real estate | 2013 |
| Imagesmith Ltd | Professional & scientific | 2023 |
| Imagine Sports Limited | Information & communication | 2024 |
| Imagine the Day Limited | Other services | 2003 |
| Imam Tech Ltd | Wholesale & retail | 2026 |
| Imax Techsolutions Limited | Information & communication | 2012 |
| Imax Ventures Limited | Real estate | 2021 |
| Imech Installations Ltd | Construction | 2007 |
| IMH Project Solutions Ltd | Professional & scientific | 2012 |
| IMH Tenura Ltd | Construction | 2024 |
| Imie Services Limited | Professional & scientific | 2024 |
| Imit Consultancy Limited | Information & communication | 2014 |
| Imja Ltd | Real estate | 2025 |
| Immaculate Installations Limited | Information & communication | 1991 |
| Immediate Commercial Solutions Limited | Financial services | 2026 |
| Immediate Mortgage Solutions Limited | Financial services | 2013 |
| Immediate Property Solutions (Warwickshire) Ltd | Real estate | 2023 |
| Imodular Homes Ltd | Construction | 2007 |
| IMP Development Management Limited | Construction | 2016 |
| IMP Hill Top Estates Limited | Construction | 2016 |
| IMP Investments Hsbc Limited | Real estate | 2018 |
| IMP Investments LBG Limited | Real estate | 2016 |
| IMP Investments Limited | Real estate | 2016 |
| IMP Investments RBS 2 Limited | Real estate | 2017 |
| IMP Investments RBS Limited | Real estate | 2017 |
| IMP Investments SHB Limited | Real estate | 2016 |
| IMP Residential 2 Limited | Real estate | 2016 |
| IMP Residential Capital Markets Limited | Financial services | 2019 |
| Impact Data U.K. Ltd | Information & communication | 2007 |
| Impact Education Services Ltd | Education | 2021 |
| Impact Visuals (Midlands) Limited | Administrative & support | 1989 |
| Impactify UK Limited | Professional & scientific | 2024 |
| Imperial Gaming Ltd | Wholesale & retail | 2020 |
| Imperial Graphics Ltd | Professional & scientific | 2009 |
| Imperial Nails Studio Limited | Other services | 2024 |
| Imperial Properties Midlands Limited | Real estate | 2014 |
| Imperial Worldwide Limited | Manufacturing | 2013 |
| Imperious Recruitment Services Ltd | Administrative & support | 2021 |