| J Doig Builders Limited | Other services | 2008 |
| J G Dental Ltd | Health & social care | 2023 |
| J G Elixir Ltd | Hospitality | 2008 |
| J Henry Gardening Ltd | Real estate | 2022 |
| J Khalil Ltd | Wholesale & retail | 2025 |
| J L Foster Lettings Ltd | Real estate | 2016 |
| J L Investments Limited | Wholesale & retail | 1975 |
| J M Scully (Holdings) Limited | Professional & scientific | 2009 |
| J S Haigh Ltd | Transport & logistics | 2019 |
| J S Jenkins Limited | Real estate | 2025 |
| J TEC Performance Ltd | Professional & scientific | 2025 |
| J Wong Enterprises Ltd | Health & social care | 2021 |
| J&A Craftworks Limited | Construction | 2024 |
| J&C Hill Properties Ltd | Real estate | 2026 |
| J&Co Builders Ltd | Construction | 2023 |
| J&M Briggs Ltd | Transport & logistics | 2026 |
| J&P Direct Ltd | Wholesale & retail | 2022 |
| J&S Jones Development Limited | Construction | 2025 |
| J&V Property Maintenance Services Ltd | Construction | 2021 |
| J. C. GAS (Parkstone) Ltd | Construction | 2013 |
| J. Glos Ltd | Transport & logistics | 2016 |
| J. Howell & SON Construction Limited | Construction | 1993 |
| J. L. Morris (Insurance Brokers) Limited | Financial services | 1971 |
| J.A.G. Property Development Ltd | Real estate | 2002 |
| J.Bolson & SON Limited | Professional & scientific | 1931 |
| J.F. & a. Coupland (Properties) Limited | Real estate | 2001 |
| J.K. MAY Southwest Limited | Health & social care | 2022 |
| J.M. Watts Commercial Property Limited | Real estate | 2012 |
| J.M.Harding & Partners Limited | Real estate | 1960 |
| J.P. Lane Developments Ltd | Construction | 2008 |
| J1A Electrical Ltd | Construction | 2019 |
| J3M Technologies Ltd | Professional & scientific | 2015 |
| JA Technical Consulting Ltd | Professional & scientific | 2025 |
| JA UK Property Ltd | Real estate | 2020 |
| JA32 Enterprises Ltd | Real estate | 2024 |
| Jabari Group Ltd | Administrative & support | 2020 |
| Jabass Aesthetics Ltd | Health & social care | 2024 |
| Jabberjays Limited | Construction | 2018 |
| Jacey House Management Company Limited | Other services | 2010 |
| Jack Murray Productions Ltd | Arts & recreation | 2023 |
| Jack Ryan Holdings Ltd | Real estate | 2024 |
| Jack the Tutor Ltd. | Professional & scientific | 2015 |
| Jackie Dunn Project Management Ltd | Construction | 2021 |
| Jackmanifoldtv Ltd | Information & communication | 2021 |
| Jackson Distribution Limited | Wholesale & retail | 2005 |
| Jackson Fish Ltd | Hospitality | 2024 |
| Jacksons Investments Limited | Professional & scientific | 2007 |
| Jacob Carr Homes (Fareham) Limited | Administrative & support | 2016 |
| Jacob Carr Homes (Ground Floor) Limited | Real estate | 2023 |
| Jacob Carr Homes (Havant) Limited | Administrative & support | 2016 |
| Jacob Carr Homes (Poole Quay) Limited | Construction | 2017 |
| Jacob Carr Homes (Salterns) Ltd | Real estate | 2015 |
| Jacob Parry Ltd | Professional & scientific | 2017 |
| Jacqueline Challenor Consultancy Ltd | Professional & scientific | 2022 |
| Jacs Retail Consultancy Ltd | Professional & scientific | 2025 |
| Jade Poole Limited | Households | 2023 |
| Jade-Aden Developments Ltd | Construction | 2026 |
| Jade-Aden Ltd | Construction | 2022 |
| Jade-Aden Services Holdings Limited | Construction | 2021 |
| Jade-Aden Services Limited | Construction | 1992 |
| Jadebeach Limited | Hospitality | 2013 |
| Jaguar Point Limited | Construction | 2013 |
| Jaino Ltd | Wholesale & retail | 2025 |
| Jaivian Ltd | Wholesale & retail | 2024 |
| JAK and Ronnie Adlington Ltd | Hospitality | 2018 |
| Jakir Hossain PA Ltd | Wholesale & retail | 2025 |
| Jakmat-Trans Ltd | Transport & logistics | 2025 |
| JAL Studios Ltd | Professional & scientific | 2020 |
| JAM KAL Ltd | Construction | 2008 |
| Jambala Ltd | Wholesale & retail | 2026 |
| James & James Group Ltd | Financial services | 2021 |
| James Arthur Holland IT Consultancy Ltd | Information & communication | 2022 |
| James Beynon Consulting Limited | Professional & scientific | 2015 |
| James Clarke Wealth Management Solutions Limited | Financial services | 2013 |
| James Coventry Design Limited | Professional & scientific | 2021 |
| James Husband Accountancy Services Limited | Professional & scientific | 2024 |
| James Park Plastering Ltd | Construction | 2024 |
| James Stratton Limited | Construction | 2015 |
| James' Tea Rooms Limited | Wholesale & retail | 2024 |
| Jamichar Limited | Professional & scientific | 1999 |
| Jamie Wollen & Associates LLP | | 2008 |
| Jamiehenryrentals Ltd | Real estate | 2025 |
| Jamila Muzammal Ltd | Wholesale & retail | 2024 |
| Jammin Jetski and Boat Services Ltd | Manufacturing | 2025 |
| Jamsvt Limited | Administrative & support | 2017 |
| Janadan Limited | Real estate | 2001 |
| Janarus Ltd | Professional & scientific | 2011 |
| Janath Ventures Limited | Information & communication | 2008 |
| Jandos Developments Limited | Real estate | 2007 |
| Jankenmef Limited | Wholesale & retail | 2024 |
| JAQ Investments Limited | Real estate | 2011 |
| Jard Properties Limited | Real estate | 2021 |
| Jarekdorociak Ltd | Transport & logistics | 2025 |
| Jari Ltd | Transport & logistics | 2018 |
| Jaross Holdings Ltd | Financial services | 2026 |
| JAS Movement Therapy Ltd | Health & social care | 2018 |
| Jaskirat Harleen Ltd | Information & communication | 2026 |
| Jasmine Court (Bournemouth) RTM Company Limited | Households | 2016 |
| Jasmine Marine Ltd | Manufacturing | 2020 |
| Jason Abbott Financial Limited | Professional & scientific | 2025 |