| Inter - House Design Limited | Professional & scientific | 2003 |
| Inter Ceramica Limited | Wholesale & retail | 2001 |
| Inter-Vention UK Limited | Administrative & support | 2009 |
| Interact DC Limited | Information & communication | 2020 |
| Interim Digital Limited | Professional & scientific | 2017 |
| Interim Property Services Limited | Real estate | 2012 |
| Interior Flair Ltd | Wholesale & retail | 2010 |
| International Prestige Limited | Extraterritorial | 2026 |
| International Securities Limited | Extraterritorial | 2026 |
| International Union of Training Academy Ltd | Wholesale & retail | 2024 |
| Interpr Limited | Professional & scientific | 2012 |
| Intime (Leeds) Limited | Transport & logistics | 2007 |
| Intime Express Direct LLP | | 2011 |
| Intramech Limited | Real estate | 2014 |
| Intrinsic Vehicle Movement Ltd | Transport & logistics | 2023 |
| Intru Ltd | Information & communication | 2018 |
| Inventivo Limited | Information & communication | 2016 |
| Inverico Limited | Professional & scientific | 2019 |
| Investco Charlie 1 Ltd | Financial services | 2025 |
| Investco Cian 1 Ltd | Financial services | 2025 |
| Investco Helen 1 Ltd | Financial services | 2025 |
| Investco TOM 1 Ltd | Financial services | 2025 |
| Ipcjc Limited | Construction | 2019 |
| IPH Investments Limited | Real estate | 1989 |
| IPN Partners Limited | Other services | 2012 |
| IR Engineering Ltd | Professional & scientific | 2025 |
| IR Property Legacy Ltd | Real estate | 2024 |
| Iran Limited | Extraterritorial | 2026 |
| IRG Construction Services Limited | Construction | 2023 |
| Iron Bloom Group Ltd | Wholesale & retail | 2024 |
| Iron Dominion Ltd | Education | 2026 |
| Iron Panther Ltd | Extraterritorial | 2012 |
| Ironclad Enterprises Ltd | Wholesale & retail | 2024 |
| Ironhart Sports Limited | Administrative & support | 2024 |
| Ironstream Limited | | 2012 |
| IRT Media Group Limited | Information & communication | 2018 |
| Irven Hill Limited | Information & communication | 1996 |
| Isabella Property Ltd | Real estate | 2022 |
| Iskandia Technologies Limited | Administrative & support | 2003 |
| Island Lane Limited | Financial services | 2020 |
| Issa TS Limited | Hospitality | 2024 |
| Istabraq for Trade Ltd | Wholesale & retail | 2021 |
| Isurium Limited | Other services | 2019 |
| IT Hardware Installation Services Ltd | Information & communication | 2004 |
| IT Intelligence Ltd | Information & communication | 2012 |
| IT Sales Recruiter Limited | Administrative & support | 2023 |
| Italiani Limited | Wholesale & retail | 2024 |
| ITP Consultancy Ltd | Administrative & support | 2018 |
| ITS Allus Limited | Professional & scientific | 2025 |
| Ivor Norton Management Services Limited | | 1974 |
| IVY Gate Properties Limited | Construction | 2025 |
| IVY Red Resources Ltd | Administrative & support | 2021 |
| IX Sports Limited | Arts & recreation | 2016 |
| Izdihar Alqamar Ltd | Wholesale & retail | 2026 |
| Izziewevents Ltd | Administrative & support | 2023 |
| J & F Wilson Plumbing & Heating Limited | Construction | 2009 |
| J & G Painting and Decorating Limited | Construction | 2008 |
| J & H-W Partners LLP | | 2016 |
| J & K Abbs Services Limited | Administrative & support | 2017 |
| J & S Noble Limited | Real estate | 2019 |
| J a Mahon Limited | Professional & scientific | 2014 |
| J and N Tapster Limited | Administrative & support | 2020 |
| J B S Programme Management Limited | Information & communication | 2009 |
| J BUG Ltd | Other services | 2025 |
| J C Robinson (Yorkshire) Limited | Construction | 2018 |
| J D Electrical Ripon Ltd | Construction | 2013 |
| J G Developments (Yorkshire) Limited | Construction | 2021 |
| J G Strategies Limited | Financial services | 2010 |
| J H Rolph & SON Ltd | Manufacturing | 2003 |
| J H Transport Leeds Limited | Transport & logistics | 2020 |
| J Hanley Consulting Ltd | Professional & scientific | 2025 |
| J Lyon Consultants Limited | Administrative & support | 2023 |
| J M Supplies Ltd | Manufacturing | 2003 |
| J M W (Glasshouses) Ltd | Construction | 2006 |
| J Moss Enterprises Ltd | Wholesale & retail | 2025 |
| J Night Films Limited | Information & communication | 2012 |
| J O M Electrical (Leeds) Ltd | Manufacturing | 2011 |
| J P Cooper FS Ltd | Professional & scientific | 2018 |
| J Palmer Architects Limited | Professional & scientific | 2025 |
| J S Electrical (Harrogate) Ltd | Construction | 2016 |
| J Todd & SON Ltd | Wholesale & retail | 2023 |
| J Turner Consultancy Services Limited | Professional & scientific | 2011 |
| J&A Alderson Properties Limited | Real estate | 2016 |
| J&D Enterprises Leeds Limited | Hospitality | 2019 |
| J&J Europe Limited | Wholesale & retail | 2023 |
| J&K Property Ltd | Households | 2022 |
| J&L Acquisitions Limited | Real estate | 2025 |
| J&M Harris Estates Ltd | Real estate | 2026 |
| J&P Capital 4 Limited | Extraterritorial | 2018 |
| J. Hewson (Builders) Limited | Construction | 1978 |
| J. Marsland & Sons Limited | Extraterritorial | 1917 |
| J. Meadus Contract Flooring Limited | Construction | 2012 |
| J.Butterfield & Co.(Holdings)Limited | Financial services | 1926 |
| J.G. Bellerby (Farms) Limited | Agriculture & fishing | 1997 |
| J.G. Investments Limited | Real estate | 1944 |
| J.M. Dodd Limited | Information & communication | 2001 |
| J.N. Barber Limited | Wholesale & retail | 2006 |
| J.N. Bentley Properties Limited | Financial services | 2013 |
| J.T. & C.S. Simpson Limited | Wholesale & retail | 2003 |
| J1 HG1 Limited | Construction | 2025 |