| IAN Nicol Structural Design Limited | Administrative & support | 2015 |
| IAN Scott & Company Limited | Professional & scientific | 2002 |
| IAN Shuttler Consultancy Limited | Professional & scientific | 2022 |
| IAN Taylor Planning Partnership Limited | Administrative & support | 2009 |
| IAN Thomas Joinery Ltd | Construction | 2017 |
| IAN Walker Services Limited | Administrative & support | 2002 |
| Ianh Sport Finance Consultancy Limited | Professional & scientific | 2023 |
| IAO Services Ltd | Professional & scientific | 2020 |
| IBC Instruments Ltd | Professional & scientific | 2019 |
| Ibelts Limited | Wholesale & retail | 2013 |
| Ibeng Limited | Information & communication | 2012 |
| Ibex Design Services Limited | Administrative & support | 2007 |
| IBG Immucor Limited | Wholesale & retail | 1988 |
| Ibil Engineering Ltd | Administrative & support | 2023 |
| Ibnsinarx Ltd | Professional & scientific | 2024 |
| Ibop Ltd | Manufacturing | 2012 |
| Ibox Secure Limited | Transport & logistics | 2023 |
| Ibrahim Auto Hybrids Ltd | Wholesale & retail | 2025 |
| Ibrand Signs Limited | Professional & scientific | 2021 |
| Ibraville Limited | Information & communication | 2026 |
| Ibsm Networks Ltd | Administrative & support | 2014 |
| IBZ Limited | Administrative & support | 2014 |
| IC Consulting Services Limited | Information & communication | 2022 |
| IC Entertainment Ltd | Administrative & support | 2024 |
| IC Kartstore Ltd | Wholesale & retail | 2025 |
| Ic&C Telecom Ltd | Information & communication | 2015 |
| ICB Sear Aviation Limited | Professional & scientific | 2018 |
| ICD QS Services Limited | Administrative & support | 2016 |
| Ice & Clean Limited | Other services | 2010 |
| Ice and Slice Fresh Food Ltd | Manufacturing | 2024 |
| Ice and Slice Ltd | Manufacturing | 2026 |
| Ice Cream Van Ltd | Information & communication | 2019 |
| Ice Nine Limited | Professional & scientific | 2018 |
| Ice Secure Limited | Administrative & support | 2014 |
| Ice Technical Services Limited | Construction | 2024 |
| Icewood Design Limited | Administrative & support | 2016 |
| Ichange Solutions Ltd | Information & communication | 2014 |
| Ichiraku Services Limited | Transport & logistics | 2026 |
| Ichnostrat Consulting Ltd | Professional & scientific | 2024 |
| ICN Associates Limited | Professional & scientific | 2017 |
| ICN Services Limited | Professional & scientific | 2022 |
| Icon Electrical Services Limited | Construction | 2024 |
| Icon Services (UK) Limited | Construction | 2008 |
| Iconic Fitness Limited | Arts & recreation | 2015 |
| Iconojam 2 Ltd | Professional & scientific | 2026 |
| ICS (2079) Limited | Construction | 2007 |
| ICS Dental Limited | Health & social care | 2013 |
| ICS Dental Recruitment Ltd | Health & social care | 2024 |
| ICS Engineering Limited | Administrative & support | 2011 |
| ICS IT Consultancy Ltd | Information & communication | 2006 |
| Icsray Property Limited | Real estate | 2022 |
| ICT Procurement Ltd | Professional & scientific | 2022 |
| ID Physiotherapy Limited | Health & social care | 2010 |
| Ideal Electrical Contractors Ltd | Construction | 2011 |
| Ideal Facilities Limited | Administrative & support | 2023 |
| Ideal Homes and Lettings Ltd | Real estate | 2025 |
| Ideal Industries Holdings Limited | Professional & scientific | 2003 |
| Ideal Industries Limited | Manufacturing | 1984 |
| Ideal Lakeside Limited | Real estate | 2021 |
| Ideal Office Limited | Wholesale & retail | 2006 |
| Ideal Packaging (UK) Limited | Extraterritorial | 2011 |
| Ideal Plumbing and Heating Limited | Construction | 2002 |
| Ideal Recruit Ltd | Professional & scientific | 2022 |
| Ideal Tribe Ltd | Wholesale & retail | 2020 |
| Ideal Web Designs Ltd | Professional & scientific | 2019 |
| Ideanest Limited | Real estate | 2021 |
| Ideascope Media & Services Limited | Information & communication | 2025 |
| Identify Psychological Services Ltd | Health & social care | 2015 |
| IDP Maintenance Solutions Ltd | Professional & scientific | 2019 |
| IDP Racing Ltd | Arts & recreation | 2019 |
| IDP Security Ltd | Information & communication | 2018 |
| IDREESI381 Limited | Health & social care | 2014 |
| IDS Home Group Ltd | Financial services | 2024 |
| Idsall Consulting Limited | Administrative & support | 2024 |
| IDT Support Solutions Limited | Information & communication | 2007 |
| Idung Supply Limited | Transport & logistics | 2015 |
| IEM (NW) Limited | Professional & scientific | 2018 |
| Iesa a & D Holdings Limited | Professional & scientific | 2014 |
| Iesa a & D Limited | Professional & scientific | 2002 |
| Iesa Holdings Limited | Professional & scientific | 2007 |
| IF Consulting Services Limited | Professional & scientific | 2024 |
| Ifaad Ltd | Financial services | 2014 |
| Iffering Limited | Administrative & support | 2006 |
| Ifield House Limited | Real estate | 2025 |
| IFL (International Food League) Ltd | Hospitality | 2023 |
| Iforce Auctions Limited | Professional & scientific | 2007 |
| Iforce Limited | Administrative & support | 1997 |
| Iforce Trading Limited | Transport & logistics | 2000 |
| Ifti Group Limited | Wholesale & retail | 2019 |
| Igachi Consulting Limited | Administrative & support | 2016 |
| IGB Talent Limited | Professional & scientific | 2026 |
| Igbo Community Warrington | Health & social care | 2022 |
| IGL (Surveying) Limited | Professional & scientific | 2003 |
| Ignis TES Limited | Professional & scientific | 2017 |
| Ignite Accounts Ltd | Professional & scientific | 2019 |
| Ignite Live Ltd | Administrative & support | 2021 |
| Ignite Systems Ltd | Information & communication | 2004 |
| Ignite Your Talent Limited | Professional & scientific | 2017 |
| Ihda Limited | Information & communication | 2023 |
| IJ Hansberry Consulting Limited | Administrative & support | 2025 |