| Jetstream DCP Limited | Information & communication | 2025 |
| JG Heating and Ventilation Ltd | Construction | 2026 |
| JH Construction Midlands Ltd | Construction | 2025 |
| JI Garden Services Limited | Administrative & support | 2020 |
| Jigsaw Web Design Ltd | Information & communication | 2012 |
| Jira Group Limited | Real estate | 2026 |
| JJ Autos Garage Ltd | Wholesale & retail | 2026 |
| JJB Projects Limited | Administrative & support | 2011 |
| JJE Investments Limited | Real estate | 2025 |
| Jjppt Quality Engineering Solutions Ltd | Professional & scientific | 2024 |
| JJR Associates Ltd | Hospitality | 2007 |
| JK Online Marketing Limited | Information & communication | 2016 |
| JK Property Sourcing Ltd | Real estate | 2022 |
| JKC International Ltd | Real estate | 2020 |
| JLG Homes Limited | Real estate | 2022 |
| JM Electrical Services Limited | Construction | 1998 |
| JM Heating Solutions Ltd | Construction | 2023 |
| JM Maintenance Services Limited | Construction | 2022 |
| JMA Suli Ltd | Wholesale & retail | 2023 |
| JMC Surfacing Contractors Limited | Construction | 2000 |
| Jmca Property Limited | Real estate | 2024 |
| JMH Equestrian Ltd | Agriculture & fishing | 2022 |
| JMO Logistics Ltd | Transport & logistics | 2024 |
| Jmpi Ltd | Extraterritorial | 2016 |
| JMW Brickwork Ltd | Construction | 2026 |
| JN Walker Ltd | Agriculture & fishing | 2018 |
| Joanna Rose Arts Limited | Arts & recreation | 2018 |
| Jobie Limited | Other services | 2018 |
| John Atkins Consulting Limited | Professional & scientific | 2005 |
| John G Dowsett Limited | Manufacturing | 2009 |
| John Grace and Associates Limited | Professional & scientific | 2018 |
| John Green Enterprises Limited | Professional & scientific | 1979 |
| John Howells Associates Limited | Professional & scientific | 2016 |
| John Maguire Racing Ltd | Manufacturing | 2018 |
| Johns of Studley (Removals & Transport) Limited | Transport & logistics | 2004 |
| Johnson Combustion Limited | Administrative & support | 2015 |
| Jojos Kitchin Ltd | Hospitality | 2024 |
| Jolijo Ltd | Wholesale & retail | 2026 |
| Jolt Aromas Ltd | Wholesale & retail | 2025 |
| Jordy Blue Cabling Ltd | Construction | 2026 |
| Joseph H. Lines & Sons Limited | Manufacturing | 1972 |
| Jotika (Midlands) Software Limited | Information & communication | 1991 |
| Jotika Holdings Limited | Information & communication | 2005 |
| Jotika Property Ltd | Real estate | 2017 |
| JPA Store Ltd | Wholesale & retail | 2025 |
| JPE Investments Limited | Professional & scientific | 2016 |
| JR & JN Properties Ltd | Real estate | 2018 |
| JRH Homes Ltd | Real estate | 2026 |
| Jruk Coaching Ltd | Wholesale & retail | 2026 |
| JS Moss Enterprises Ltd | Wholesale & retail | 2025 |
| JSS Pipework Limited | Construction | 2026 |
| Jtol Ltd | Information & communication | 2015 |
| JTW Brickwork Ltd | Construction | 2025 |
| Judith Bartley Skincare Ltd | Other services | 2023 |
| Juels' Limited | Wholesale & retail | 2012 |
| Juliethdesigns Ltd | Professional & scientific | 2018 |
| Jungle Joe's Ltd | Extraterritorial | 2011 |
| Just Bread Limited | Wholesale & retail | 2022 |
| Just Breathe Life Limited | Health & social care | 2024 |
| Just Go Local Limited | Wholesale & retail | 2025 |
| Just Hubert Ltd | Transport & logistics | 2019 |
| Just Three Learning Limited | Education | 2018 |
| Just Winners Ltd | Arts & recreation | 2025 |
| Justmaths Limited | Education | 2012 |
| JWC Properties Limited | Real estate | 2020 |
| JX3 Group Limited | Construction | 2020 |
| JZK113 Services Ltd | Transport & logistics | 2026 |
| K & P Plant Movements Limited | Administrative & support | 2021 |
| K J K Sands Limited | Professional & scientific | 2016 |
| K&A Properties (Cotswolds) Limited | Real estate | 2022 |
| K&K9 Ltd | Administrative & support | 2025 |
| K&M Electrical Redditch Ltd | Manufacturing | 2020 |
| K&O Building Services Ltd | Construction | 2024 |
| K&R Group Solutions Ltd | Administrative & support | 2026 |
| K. N. Products Limited | Manufacturing | 1983 |
| K.A.N. Property Developments Limited | Real estate | 1999 |
| K.G.F. COX Limited | Professional & scientific | 2004 |
| K.K PVT Ltd | Transport & logistics | 2026 |
| K2 Utilities Limited | Administrative & support | 2011 |
| Kaai Limited | Professional & scientific | 1993 |
| KAB Social Work. Limited | Health & social care | 2012 |
| Kaczynski Limited | Wholesale & retail | 2022 |
| Kadfire Property Limited | Real estate | 2020 |
| Kaizentric Technologies Private Limited | Information & communication | 2023 |
| Kalkomat Limited | Wholesale & retail | 2014 |
| Kama Transport Ltd | Transport & logistics | 2025 |
| Kandekore Graphics Limited | Professional & scientific | 2014 |
| Kando Installations Ltd | Construction | 2020 |
| Kane Clark Auto Services Ltd | Manufacturing | 2024 |
| KAP Stores Ltd | Wholesale & retail | 2006 |
| Karma Mobility Limited | Wholesale & retail | 1999 |
| Katesten Developments Limited | Construction | 2024 |
| Katie Sutton Small Business Services Ltd | Professional & scientific | 2018 |
| Kavanagh Drylining Solutions Ltd | Construction | 2026 |
| Kavanagh Property Investments Ltd | Real estate | 2020 |
| Kay-Bee Engineering Ltd | Manufacturing | 2017 |
| Kaye GEE Consultants Limited | Professional & scientific | 2018 |
| Kazmi Consultants Ltd | Health & social care | 2023 |
| KC Bodycraft Limited | Wholesale & retail | 2010 |
| KC Properties & Holdings Limited | Households | 2025 |