| Inclusive Design Associates Ltd | Administrative & support | 2023 |
| Inclusive Management Systems Ltd | Professional & scientific | 2011 |
| Incotax Ltd | Professional & scientific | 2019 |
| Independence Living Ltd | Real estate | 2023 |
| Independent Personnel Ltd | Professional & scientific | 2011 |
| Indevflow Ltd | Transport & logistics | 2025 |
| Indibook Ltd | Information & communication | 2009 |
| Indigo Management Services Limited | Transport & logistics | 2018 |
| Indigofitness Limited | Manufacturing | 1996 |
| Individual Futures Ltd | Health & social care | 2014 |
| Individual Housing Solutions Ltd | Hospitality | 2020 |
| Individual Support Solutions Ltd | Health & social care | 2011 |
| Indra Kumari Limited | Wholesale & retail | 2021 |
| Industriserve Ltd | Professional & scientific | 2022 |
| Infinity Items Ltd | Wholesale & retail | 2021 |
| Infinity Projects Warwickshire Ltd | Construction | 2024 |
| Infinity Quality Solutions Ltd. | Professional & scientific | 2018 |
| Info-Line Solutions Limited | Wholesale & retail | 2012 |
| Infrastructure Consulting Ltd | Professional & scientific | 2007 |
| Inloco Events Ltd | Administrative & support | 2013 |
| Innerglow Coaching Ltd | Education | 2025 |
| Innocentrad Ltd | Health & social care | 2020 |
| Innov@Te Solutions Ltd | Administrative & support | 2011 |
| Innovative Materials Limited | Other services | 2017 |
| Inspired Children Ltd | Education | 2017 |
| Inspired Web Development Services Ltd | Information & communication | 2016 |
| Intaforensics Ltd | Administrative & support | 2004 |
| Integrated Solutions Contracting Limited | Construction | 2019 |
| Integrated Solutions Marine Limited | Transport & logistics | 2020 |
| Intelligent Flooring Solutions Ltd | Construction | 2015 |
| Inter-Access Floors Limited | Construction | 1997 |
| Interaxic Management Services Ltd | Information & communication | 2024 |
| Interceptor Transport Ltd | Transport & logistics | 2024 |
| Intercessors Limited | Other services | 2020 |
| Intrepid Manufacturing Limited | Manufacturing | 2011 |
| Intrepid Propco Ltd. | Real estate | 2016 |
| Intria Ltd | Professional & scientific | 2024 |
| Intrinsic Services Limited | Information & communication | 2019 |
| Intune Bodycare Ltd | Wholesale & retail | 2019 |
| Invictus at Home Ltd | Information & communication | 2016 |
| Invigorate Wellness Ltd | Other services | 2025 |
| Invincible Analytics Limited | Administrative & support | 2014 |
| Ioana Trans & Services Ltd | Transport & logistics | 2023 |
| Ionas MM Ltd | Transport & logistics | 2015 |
| Ionian Sea Ltd | Hospitality | 2025 |
| IP Cleaning (UK) Limited | Administrative & support | 2013 |
| Iq&Q Group (UK) Ltd | Administrative & support | 2022 |
| Irina Trans Ltd | Transport & logistics | 2025 |
| Iron Boar Tech Ltd | Professional & scientific | 2026 |
| Isaac SAM Limited | Real estate | 2020 |
| Iseoluwa and Co Limited | Health & social care | 2016 |
| Isis Magazine Limited | Information & communication | 2005 |
| Isla B Bridal Ltd | Wholesale & retail | 2020 |
| Islalou Limited | Professional & scientific | 2020 |
| Island Logistic Ltd | Transport & logistics | 2015 |
| Island Ritual by Nadiya Ltd | Other services | 2019 |
| Isospeed 7 Limited | Transport & logistics | 2019 |
| Issabelle Ltd | Administrative & support | 2017 |
| Istanbul Barber CV11 Ltd | Other services | 2026 |
| Itower Ltd | Information & communication | 2014 |
| ITS Sweet Deals Ltd | Wholesale & retail | 2026 |
| Ivan Courier Ltd | Transport & logistics | 2025 |
| Ivan J Parry Limited | Extraterritorial | 2025 |
| IVC Nuneaton Limited | Wholesale & retail | 2002 |
| Ivor King (Civil Engineering Contractors) Limited | Construction | 1974 |
| Ivor King Holdings Limited | Financial services | 2012 |
| Ivor King Properties Limited | Households | 2012 |
| IVY Beauty Limited | Other services | 2023 |
| IW Topco Limited | Real estate | 2018 |
| Iyaniwura Investments Ltd | Real estate | 2025 |
| Iza's Cakes Ltd | Manufacturing | 2020 |
| J & B Holdings (Midlands) Ltd | Financial services | 2015 |
| J & B Properties (Midlands) Ltd | Real estate | 2015 |
| J & J Holdings Property Ltd | Real estate | 2018 |
| J & P Sports CIC | Education | 2024 |
| J & S Malkin Plant Limited | Wholesale & retail | 1998 |
| J a Electrical Solutions Limited | Construction | 2016 |
| J Ahmad Consultancy Limited | Information & communication | 2006 |
| J Ashby Consulting Limited | Professional & scientific | 2024 |
| J B Coulthurst Limited | Construction | 2013 |
| J Blue Star Limited | Construction | 2025 |
| J C IT Consultants Ltd | Professional & scientific | 2019 |
| J C Machining Limited | Manufacturing | 2012 |
| J Chahal Haulage Limited | Transport & logistics | 2015 |
| J E Young Property Services Ltd | Real estate | 2024 |
| J M Callington Ltd | Professional & scientific | 2019 |
| J M Engineering and Modelling Limited | Administrative & support | 2006 |
| J M Steele Accountancy Limited | Professional & scientific | 2014 |
| J Mmta Goods Ltd | Wholesale & retail | 2026 |
| J Owen Builders and Decorators Ltd | Construction | 2008 |
| J P Industrial Flooring Ltd | Construction | 2024 |
| J Prime Plumbing and Heating Ltd | Construction | 2021 |
| J R Building Supplies Ltd | Wholesale & retail | 2025 |
| J R Executive Products Limited | Wholesale & retail | 2007 |
| J S Horton Tipper Grab Hire Ltd | Water & waste | 2026 |
| J W Morley PS Ltd | Extraterritorial | 2008 |
| J W Morley Transport Limited | Transport & logistics | 2012 |
| J White Farm Services Ltd | Agriculture & fishing | 2020 |
| J Wilks Transport Limited | Transport & logistics | 2018 |
| J Williamson Electrical Limited | Construction | 2015 |