| International Advice Limited | Financial services | 2017 |
| International Construction Design and Management Limited | Professional & scientific | 1994 |
| International Safety Technology Limited | Extraterritorial | 2022 |
| Intrepid Resolution Ltd | Information & communication | 2025 |
| Introcom International Limited | Professional & scientific | 2013 |
| Invan Holdings Ltd | Financial services | 2026 |
| Invent Production Services Limited | Professional & scientific | 2016 |
| Inventor Manufacturer Investor Ltd | Professional & scientific | 2022 |
| Iopsis Limited | Professional & scientific | 2021 |
| IP Enclosures UK Limited | Wholesale & retail | 2021 |
| Ipek Gultekin Ltd | Wholesale & retail | 2025 |
| IPP Industrial Production Processes Limited | Wholesale & retail | 1998 |
| Iproductions Limited | Information & communication | 2006 |
| Irfox Ltd | Wholesale & retail | 2025 |
| Ironwood Trade Limited | Wholesale & retail | 2026 |
| Isenmark Trade Limited | Wholesale & retail | 2026 |
| Isigma Ltd | Professional & scientific | 2018 |
| Isles Safety Ltd | Professional & scientific | 2026 |
| Isoserve Limited | Other services | 2009 |
| Istanbul Kebab and Pizza Limited | Hospitality | 2025 |
| Istar Limited | Professional & scientific | 2013 |
| It's From Blursday Limited | Wholesale & retail | 2025 |
| Italian Takeaway Bromsgrove Limited | Hospitality | 2023 |
| Itooling Absolute Ltd | Professional & scientific | 2017 |
| IVY House Consulting Rooms Ltd | Health & social care | 2022 |
| Iwjs Specialist Services Limited | Transport & logistics | 2010 |
| IX Corporate Services Ltd | Other services | 2020 |
| J & J Property Management (Midlands) Ltd | Real estate | 2020 |
| J & J Shrewsbury Developments Limited | Construction | 2018 |
| J & J Yoga Ltd | Arts & recreation | 2024 |
| J and L FOX Designs Ltd | Professional & scientific | 2023 |
| J B Contracting Ltd | Administrative & support | 2014 |
| J B Scaffolding (West Midlands) Ltd | Construction | 2011 |
| J E E Holmes Holdings Limited | Financial services | 2026 |
| J E L Bromsgrove Holdings Ltd | Real estate | 2018 |
| J Hingley Utilities Ltd | Energy | 2026 |
| J J S Roofing Contractors Limited | Construction | 2021 |
| J K Hubscher Enterprises Limited | Health & social care | 2018 |
| J K Murphy Limited | Health & social care | 2026 |
| J Marylebone Limited | Hospitality | 2023 |
| J S Holder Limited | Professional & scientific | 2016 |
| J Stewart Services Ltd | Other services | 2018 |
| J&Mp Ltd | Professional & scientific | 2026 |
| J. Markham Computing Limited | Information & communication | 1998 |
| J. Refrigeration Limited | Other services | 1998 |
| J.A. LUX Properties Ltd | Real estate | 2024 |
| J.A. LUX Transport Services Ltd | Transport & logistics | 2024 |
| J.H.Wormington and SON Limited | Agriculture & fishing | 1961 |
| J.J Rocke General Builders Limited | Construction | 2014 |
| J.K. Plumbing and Heating Services Limited | Construction | 2005 |
| J.K.I. Fabrications Limited | Manufacturing | 2017 |
| J.K.I. Limited | Construction | 2002 |
| J.P.M. Housing Limited | Real estate | 2004 |
| J.W.Haulage & Trading Limited | Extraterritorial | 1970 |
| J2K Transport Logistics Ltd | Transport & logistics | 2025 |
| JA Mechanical Building Services Ltd | Energy | 2025 |
| JAC Court Ltd | Real estate | 2017 |
| Jackson Building Group Ltd | Construction | 2020 |
| Jackson Building Ltd | Administrative & support | 2011 |
| Jacomars Limited | Real estate | 2023 |
| Jade Development Enterprises Limited | Construction | 2014 |
| Jagascoigne Ltd | Administrative & support | 2024 |
| JAI Guruji Success Ltd | Wholesale & retail | 2023 |
| JAK Projects & Services Ltd | Construction | 2020 |
| JAM Brothers Music Ltd | Information & communication | 2023 |
| JAM Brothers Records Ltd | Information & communication | 2023 |
| James Bobin Limited | Information & communication | 2018 |
| James Eden Properties Ltd | Real estate | 2025 |
| James Mark Construction Ltd | Construction | 2016 |
| Jane Ward Travel Limited | Administrative & support | 2011 |
| Jaquest Limited | Arts & recreation | 2018 |
| Jason's Technical Services Ltd | Professional & scientific | 2018 |
| Jawan Ltd | Wholesale & retail | 2021 |
| Jaykay Events Ltd | Extraterritorial | 2026 |
| Jays Groundworks Limited | Construction | 2019 |
| Jays Jewels Ltd | Wholesale & retail | 2020 |
| JB Contract Flooring Ltd | Construction | 2025 |
| JB Polishing Supplies Ltd | Wholesale & retail | 2023 |
| JB Properties Solutions Ltd | Real estate | 2026 |
| JBL Print Limited | Manufacturing | 2015 |
| JBUSINESS247 Ltd | Wholesale & retail | 2023 |
| JC Space Limited | Real estate | 2017 |
| JCP Integrated Services Ltd | Construction | 2019 |
| Jcsa Properties Limited | Real estate | 2017 |
| Jcsb Limited | Hospitality | 2024 |
| JD Elite Coaching Ltd | Other services | 2023 |
| JD Mechanical Services Limited | Construction | 2018 |
| JDC Networks Limited | Information & communication | 2006 |
| JDV Associates Ltd | Professional & scientific | 2025 |
| Jeanies Cleaning Angels Ltd | Administrative & support | 2017 |
| Jebentus Limited | Arts & recreation | 2006 |
| JEF Products Ltd | Manufacturing | 2011 |
| Jefferies Tyres Limited | Wholesale & retail | 2025 |
| JEG Investments Ltd | Real estate | 2024 |
| Jemp Limited | Administrative & support | 2009 |
| Jeremy Beaman Limited | Other services | 2007 |
| Jeremy S. Hughes Limited | Professional & scientific | 2014 |
| Jeswicks Property Services Limited | Real estate | 2020 |
| JET LAG Girl Limited | Financial services | 2025 |
| Jetivo Holdings Limited | Administrative & support | 2025 |