| Internode Pharma Ltd | Wholesale & retail | 2023 |
| Intertech Recruitment Limited | Administrative & support | 2005 |
| Intertrade Distribution Limited | Wholesale & retail | 2023 |
| Interventional Radiology Solutions Ltd | Health & social care | 2024 |
| Intransit Couriers Limited | Transport & logistics | 2023 |
| Intrigue Software Ltd | Information & communication | 2010 |
| Inufit Ltd | Construction | 2019 |
| Inva Consulting Limited | Professional & scientific | 2012 |
| Investgrow Financial Services Ltd | Financial services | 2020 |
| Investgrow Ltd | Real estate | 2018 |
| Investing Future Limited | Financial services | 2015 |
| Invicta Memorials Limited | Extraterritorial | 1977 |
| IP Holdings (Midlands) Limited | Professional & scientific | 2013 |
| IP Wilcox Limited | Construction | 2013 |
| Iprolive Limited | Manufacturing | 2026 |
| Ipure Limited | Administrative & support | 2026 |
| IQ Care Limited | Health & social care | 2017 |
| IQ Property Limited | Real estate | 2016 |
| IR Media Limited | Administrative & support | 2004 |
| Irie Logistics Ltd | Other services | 2021 |
| Irimi Developments Limited | Construction | 2019 |
| Iris Contractors Ltd | Construction | 2022 |
| Ironmouth Productions Ltd | Arts & recreation | 2015 |
| Irregular Insulation Ltd | Manufacturing | 2016 |
| Irwin & Company (Accountants) Limited | Financial services | 2002 |
| Irwin Insolvency Limited | Professional & scientific | 2017 |
| Ishem Holdings Limited | Real estate | 2015 |
| Ishem Limited | Professional & scientific | 2002 |
| Isles Investments Limited | Financial services | 2026 |
| Isles Lowe Limited | Real estate | 2025 |
| Ismails Locums Ltd | Administrative & support | 2019 |
| ISTYLE4U Ltd | Administrative & support | 2016 |
| Isys-Purple Ltd | Information & communication | 2025 |
| Italian Kitchen Boldmere Ltd | Hospitality | 2021 |
| Italian Riviera Limited | Hospitality | 2024 |
| Itec Group UK Ltd | Manufacturing | 2017 |
| Itil Service Design Limited | Information & communication | 2015 |
| ITS Getting Hot in Here Ltd | Arts & recreation | 2025 |
| ITS Lean Limited | Information & communication | 2022 |
| Itward Ltd | Information & communication | 2013 |
| Iwantapersonaltrainer Limited | Arts & recreation | 2011 |
| IZI Property Problem Solvers Limited | Real estate | 2018 |
| J & a Distribution Limited | Wholesale & retail | 2025 |
| J & B Carpets (of Walmley) Limited | Wholesale & retail | 1984 |
| J & C Property (Birmingham) Limited | Real estate | 2017 |
| J & H Consultants Ltd | Information & communication | 2017 |
| J & H Developers Limited | Real estate | 2016 |
| J & N Steels Limited | Administrative & support | 2017 |
| J & P Financial Services Limited | Financial services | 2008 |
| J & S Dundon Consulting Ltd | Professional & scientific | 2018 |
| J a Consulting Limited | Professional & scientific | 1994 |
| J and P Financial Services Holdings Limited | Administrative & support | 2021 |
| J and Q Taxi Ltd | Transport & logistics | 2022 |
| J Brown Electrical Services Limited | Construction | 2025 |
| J Christopher Consulting Ltd | Education | 2025 |
| J D GAS & Plumbing Solutions Ltd | Construction | 2020 |
| J Darby Limited | Professional & scientific | 2020 |
| J H Air Conditioning Services Ltd | Manufacturing | 2018 |
| J H Penn Ltd | Construction | 2016 |
| J Hylton & Sons Limited | Other services | 2002 |
| J K H Logistics Ltd | Transport & logistics | 2020 |
| J K M Motorcentre Limited | Wholesale & retail | 2013 |
| J L Dolan Brickwork Limited | Construction | 2025 |
| J M Aulman & Co Limited | Professional & scientific | 2019 |
| J P 84 Investment Ltd | Real estate | 2024 |
| J&D Homes Ltd | Real estate | 2023 |
| J&H Harman Limited | Construction | 2020 |
| J&S Innovatives Ltd | Wholesale & retail | 2021 |
| J. D-M Agency Limited | Extraterritorial | 1987 |
| J. Greenway & Sons Limited | Construction | 2003 |
| J. Kynaston Limited | Extraterritorial | 1958 |
| J. Roberts (SPV) Limited | Water & waste | 1989 |
| J. Roberts Property Limited | Financial services | 2016 |
| J. Steadman & Sons Limited | Extraterritorial | 1962 |
| J.A.M. Industrial Roofing and Cladding Ltd | Construction | 2024 |
| J.D. Groundworks Limited | Construction | 2004 |
| J.D. Plant Hire Limited | Administrative & support | 2020 |
| J.H. Kenyon Limited | Extraterritorial | 1972 |
| J.H. Raven Limited | Extraterritorial | 1966 |
| J.J. Crowhurst Limited | Wholesale & retail | 1980 |
| J.Latham Ltd | Agriculture & fishing | 2024 |
| J.M Building & Property Maintenance Ltd | Construction | 2024 |
| J.M.R. Sales & Consultancy Limited | Professional & scientific | 2009 |
| J.S.G Sutton Ltd | Professional & scientific | 2012 |
| J.W. Tate & SON Limited | Extraterritorial | 1965 |
| J.W.Tate & Son(Holdings)Limited | Extraterritorial | 1965 |
| J2C Network Consulting Ltd | Information & communication | 2023 |
| J2G2 Limited | Administrative & support | 2025 |
| J9 Foodbarn Ltd | Hospitality | 2026 |
| Jaak Trading Ltd | Wholesale & retail | 2025 |
| Jaba Associates Limited | Professional & scientific | 2007 |
| Jack Adkins (Midlands) Limited | Professional & scientific | 2018 |
| Jack LEE & Sons Limited | Extraterritorial | 1955 |
| Jack Maintenance Services Ltd | Construction | 2026 |
| Jack Meredith Ltd | Information & communication | 2023 |
| Jack Pruen Limited | Real estate | 1928 |
| Jacks Properties Ltd | Real estate | 2013 |
| Jackson Calvert Limited | Professional & scientific | 2015 |
| Jackson Hall (Property) Limited | Real estate | 2013 |
| Jacobs N Property Limited | Real estate | 2024 |