| Instalair (Midlands) Ltd | Manufacturing | 2000 |
| Insulation and Rendering Ltd | Construction | 2025 |
| Intelwaves Ltd | Information & communication | 2026 |
| Interclamp Ltd | Wholesale & retail | 1981 |
| International Tube & Fittings Limited | Extraterritorial | 2018 |
| International Vape Ltd | Wholesale & retail | 2025 |
| International Vape Shop Ltd | Wholesale & retail | 2026 |
| IQ Facilities Management Ltd | Construction | 2026 |
| Iqbal Ventures Limited | Hospitality | 2025 |
| Iris Commercials Fleet Support Limited | Wholesale & retail | 2023 |
| Islam Freedom Services CIC | Education | 2022 |
| Itec Climatic Solutions Ltd | Other services | 1983 |
| Itec Industrial Holdings Limited | Financial services | 2021 |
| Itgirlstudios Ltd | Other services | 2025 |
| J & J Property Renovations & Construction Ltd | Real estate | 2023 |
| J & N D Holdings Ltd | Administrative & support | 2026 |
| J & S Sanghera Limited | Health & social care | 2008 |
| J & S Stevens Limited | Hospitality | 2008 |
| J a Brown & Co Ltd | Wholesale & retail | 2020 |
| J a Hughes Transport Ltd | Transport & logistics | 2025 |
| J Bracewell & Sons Limited | Construction | 2018 |
| J C Auto's Limited | Wholesale & retail | 2015 |
| J C D Crane and Lifting Gear Company Limited | Manufacturing | 1991 |
| J C D Tools & Lifting Gear Limited | Manufacturing | 2000 |
| J C Properties & Investments Limited | Real estate | 2019 |
| J Casting Services Limited | Manufacturing | 2025 |
| J Foster (Painting & Decorating) Limited | Construction | 2020 |
| J Hickton Properties Ltd | Real estate | 2020 |
| J W Brick & Block Work Limited | Construction | 2021 |
| J W Roofing Limited | Construction | 2015 |
| J&A Nails Spa Ltd | Other services | 2025 |
| J&D Renovations Ltd | Construction | 2015 |
| J. B. Products (Dudley) Limited | Manufacturing | 1998 |
| J. Roberts Bronze Components Limited | Manufacturing | 1939 |
| J.T.C. Catering Limited | Hospitality | 2024 |
| J9 Signs Limited | Professional & scientific | 2024 |
| Jack Blakeway Coaching Ltd | Health & social care | 2025 |
| Jacksons Doors & Gates Ltd | Manufacturing | 2026 |
| James Smith Painter & Decorator Limited | Construction | 2025 |
| JAY. C Solutions Limited | Construction | 2022 |
| JC & Co. Limited | Wholesale & retail | 2009 |
| JC & LC Properties Ltd | Real estate | 2020 |
| JC Pristclean Ltd | Administrative & support | 2022 |
| JC Self Drive Limited | Administrative & support | 2025 |
| JCG Auto's Limited | Wholesale & retail | 2005 |
| JD Retail (Midlands) Limited | Wholesale & retail | 2024 |
| JDA Mechanical Services Limited | Construction | 2017 |
| JDT Management Ltd | Education | 2017 |
| Jennen Investments Limited | Financial services | 2020 |
| Jennings & Gilchreaste Limited | Real estate | 2008 |
| Jenotec Limited | Wholesale & retail | 2021 |
| Jersey's Diner Limited | Hospitality | 2025 |
| Jersey's Takeaways Limited | Hospitality | 2024 |
| JFL Logs and Coal Suppliers Ltd | Wholesale & retail | 2020 |
| JG Technical Services Limited | Professional & scientific | 2024 |
| JGL17 Ltd | Real estate | 2017 |
| JGL18 Ltd | Real estate | 2017 |
| JH Environmental & Cleansing Services Limited | Water & waste | 2008 |
| JHL Construction & Building Services Ltd | Construction | 2026 |
| JHL Construction Limited | Construction | 2019 |
| JHM (Midlands) Limited | Wholesale & retail | 2013 |
| Jiah Ltd | Real estate | 2025 |
| JIF Fasteners Limited | Manufacturing | 2003 |
| Jimtonic Limited | Hospitality | 2019 |
| JJR Catering Ltd | Hospitality | 2024 |
| JJS Autos Limited | Wholesale & retail | 2011 |
| JK Essentials Ltd | Professional & scientific | 2023 |
| JLR Maintenance Group Limited | Wholesale & retail | 2024 |
| JM3 Engineering Ltd | Professional & scientific | 2024 |
| JMS 71 Ltd | Administrative & support | 2017 |
| JNH Renovate Limited | Construction | 2018 |
| Joanna Leas Limited | Other services | 2009 |
| Joe's Diner (Tenby) Limited | Hospitality | 2021 |
| Joe's Gift Shop (Tenby) Limited | Wholesale & retail | 2025 |
| Joe's Ice Cream Parlour (Tenby) Limited | Wholesale & retail | 2025 |
| John Hadley Commercials Limited | Wholesale & retail | 2013 |
| Johnson Engineering Services Limited | Manufacturing | 2016 |
| JR Health Ltd | Health & social care | 2014 |
| JS Everstone Holdings Ltd | Real estate | 2025 |
| JSA Construct Ltd | Construction | 2015 |
| JSA Corporate Group Ltd | Real estate | 2024 |
| JSA Corporate Ltd | Professional & scientific | 2019 |
| JSC Building Contractors Ltd | Construction | 2021 |
| JSC Property Management Ltd | Households | 2024 |
| Jtdesigns Liquid Coatings Ltd | Construction | 2025 |
| JTS Construction Surveying Ltd | Construction | 2025 |
| Juke Box Sales Limited | Wholesale & retail | 2009 |
| Julie Neason Consulting Ltd | Information & communication | 2021 |
| Junior Enterprises Limited | Transport & logistics | 2013 |
| Jutla Investments Ltd | Real estate | 2020 |
| K G Transport (Midlands) Ltd | Transport & logistics | 2024 |
| K'S Electrical Engineers and Contractors Ltd | Construction | 2012 |
| K.B.Grove(Developments)Limited | Real estate | 1959 |
| K.I.G. Limited | Financial services | 1996 |
| Kaakyire Ventures Ltd | Wholesale & retail | 2026 |
| Kaizer Shop Limited | Wholesale & retail | 2023 |
| Kalsi Property Ltd | Real estate | 2017 |
| Kalu Limited | Manufacturing | 2002 |
| Kandykartel Ltd | Wholesale & retail | 2025 |
| Kapj Limited | Real estate | 2025 |