| Ieroya Ltd | Administrative & support | 2019 |
| Igcs Business Services Limited | Financial services | 2011 |
| IGM Financial Services Ltd | Professional & scientific | 2015 |
| Ilex Joinery UK Ltd | Construction | 2013 |
| Impact Electrical and Plumbing Ltd | Construction | 2020 |
| Impact Property Innovation Ltd | Real estate | 2021 |
| Impact Steam Ltd | Professional & scientific | 2014 |
| Imperial Court Residents (Kidderminster) Limited | Households | 2025 |
| Imperial Gardens Management Company Limited | Households | 2011 |
| Imperial Hvac Limited | Construction | 2023 |
| Imperium Stud Ltd | Agriculture & fishing | 2022 |
| IN the Chains Shop Ltd | Wholesale & retail | 2021 |
| IN the Saddle Limited | Administrative & support | 1999 |
| Incartech UK Limited | Manufacturing | 2007 |
| Industrial Automation Limited | Professional & scientific | 2022 |
| Industrial Maintenance Supplies Limited | Wholesale & retail | 2023 |
| Industrial Outsourcing Limited | Professional & scientific | 2016 |
| Industrial Seals Limited | Other services | 1993 |
| Inenvo Limited | Wholesale & retail | 2020 |
| Infinitas Safety Limited | Professional & scientific | 2021 |
| Infinity Home Care Ltd | Health & social care | 2016 |
| Infusion Systems Ltd | Information & communication | 2018 |
| Ingenious IP Solutions Ltd. | Professional & scientific | 2025 |
| Ingham Business Solutions Ltd | Wholesale & retail | 2022 |
| Inner Symposium Ltd | Administrative & support | 2016 |
| Innerflow Percussion CIC | Education | 2024 |
| INNOVATIVE3DPRINTS Ltd | Wholesale & retail | 2025 |
| Innovo Energy Limited | Manufacturing | 2016 |
| Inrentix Ltd | Wholesale & retail | 2024 |
| Inspire New Media Limited | Administrative & support | 2016 |
| Integrity Electrical Contractors Ltd | Construction | 2015 |
| Intelligent Sourcing Services Ltd | Professional & scientific | 2023 |
| Intergas Heating Limited | Construction | 2007 |
| Intermetal Resources Limited | Administrative & support | 2010 |
| International Supermarket 1 Ltd | Wholesale & retail | 2025 |
| International Supermarket NMA Ltd | Wholesale & retail | 2026 |
| Interpump Hydraulics (UK) Ltd | Manufacturing | 2012 |
| Interwoven Arts CIC | Professional & scientific | 2026 |
| Intracon AMS Ltd | Professional & scientific | 2026 |
| Inumbers Limited | Information & communication | 2014 |
| Irlon Laundry Limited | Manufacturing | 2015 |
| Irondim Ltd | Transport & logistics | 2019 |
| Ironserene Ltd | Administrative & support | 2019 |
| Isaac Bros Property Management Ltd | Real estate | 2022 |
| Isae Group Limited | Professional & scientific | 2005 |
| Ishtarzios Ltd | Administrative & support | 2023 |
| Istraltix Ltd | Administrative & support | 2024 |
| IT Works (2012) Limited | Information & communication | 2012 |
| ITC Brokerage Limited | Wholesale & retail | 2013 |
| ITM Group Limited | Professional & scientific | 2019 |
| Iulian Enache 92 Ltd | Transport & logistics | 2026 |
| Ivor Cider Ltd | Manufacturing | 2022 |
| Ivoryfest Ltd | Transport & logistics | 2019 |
| Iyou Ltd | Households | 2024 |
| J & D Couriers Limited | Transport & logistics | 2003 |
| J & S Foods Limited | Hospitality | 1996 |
| J & S Midland Services Limited | Administrative & support | 2004 |
| J and G Properties Holdings Ltd | Real estate | 2024 |
| J and S Invest Limited | Administrative & support | 2019 |
| J and W Developments Limited | Real estate | 2023 |
| J Bayliss Properties Limited | Real estate | 2006 |
| J Becke Heating Limited | Construction | 2025 |
| J Becke Homes Limited | Real estate | 2020 |
| J C Racing Products Limited | Arts & recreation | 2013 |
| J E Property Management Ltd | Real estate | 2007 |
| J J Carpentry Services (Worcestershire) Limited | Construction | 2014 |
| J L’S Hide Away Ltd | Other services | 2024 |
| J M Hatfield Electrical Ltd | Construction | 2023 |
| J Marsden Properties Ltd | Real estate | 2022 |
| J Mondon Ltd | Professional & scientific | 2025 |
| J S Newsham Limited | Agriculture & fishing | 2011 |
| J S Walsh Painting & Decorating Ltd | Construction | 2020 |
| J Stanley Transport Consultancy Ltd | Professional & scientific | 2021 |
| J Turner Automotive Limited | Wholesale & retail | 2025 |
| J Wassell Ltd | Real estate | 2025 |
| J&D Developers Limited | Extraterritorial | 2015 |
| J&J Rigging Ltd | Information & communication | 2024 |
| J&Kl Enterprises Limited | Hospitality | 2025 |
| J. S. Optical Limited | Health & social care | 2002 |
| J.A. Williams (Ceilings and Partitions) Limited | Construction | 1989 |
| J.B Vehicle Services Ltd | Wholesale & retail | 2025 |
| J.T.M 2025 Ltd | Construction | 2025 |
| J.W.Bird (Haulage) Ltd | Transport & logistics | 2019 |
| J2 Business Consulting Services Ltd | Professional & scientific | 2019 |
| JA Traffics Ltd | Construction | 2025 |
| Jack Mcloughlin Ltd | Other services | 2019 |
| Jahtabie Ltd | Construction | 2025 |
| Jaiahs TM Ltd | Construction | 2023 |
| Jake Egginton Management Ltd | Arts & recreation | 2014 |
| Jake Egginton Property Management Ltd | Real estate | 2025 |
| Jake Lindsey Transport Limited | Transport & logistics | 2022 |
| JAM Installations Limited | Construction | 2008 |
| Jamates Ltd | Wholesale & retail | 2018 |
| Jambats Ltd | Wholesale & retail | 2022 |
| James England Manufacturing Ltd | Manufacturing | 2023 |
| Jamie Wall Racing Ltd | Education | 2020 |
| Jams Management Ltd | Professional & scientific | 2019 |
| Janalio Fire Risk Management Limited | Professional & scientific | 2024 |
| Janitorial Direct Limited | Wholesale & retail | 1991 |
| Jarrett Developments Limited | Construction | 2012 |