| J C Barrons Holdings Ltd | Financial services | 2026 |
| J C Jordan Limited | Information & communication | 2015 |
| J Cossins & Sons Limited | Agriculture & fishing | 1960 |
| J D Lifestyles Ltd | Wholesale & retail | 2019 |
| J Franses and SON Limited | Wholesale & retail | 1999 |
| J K Cars & Commercials Ltd | Wholesale & retail | 2022 |
| J K Lifts Ltd | Construction | 2016 |
| J Landen Scaffolding Limited | Construction | 2016 |
| J Larus Consulting Limited | Health & social care | 2025 |
| J M Courier Services Ltd | Transport & logistics | 2019 |
| J MAY & SON Ltd | Wholesale & retail | 2020 |
| J Pawel Ltd | Other services | 2021 |
| J R Diagnosticar Limited | Wholesale & retail | 2024 |
| J R Lawrence Ltd | Professional & scientific | 2023 |
| J R Print Ltd | Manufacturing | 2000 |
| J Radwan Limited | Real estate | 2016 |
| J S Jerrett Limited | Wholesale & retail | 2001 |
| J T Elec Ltd | Administrative & support | 2018 |
| J T Plant Sales Solutions Limited | Other services | 2019 |
| J Tobias Limited | Administrative & support | 2005 |
| J Towler Construction Ltd | Construction | 2019 |
| J White Consultancy Services Ltd | Construction | 2025 |
| J Wilmar Property Ltd | Real estate | 2026 |
| J&L Diamond Estates Ltd | Construction | 2024 |
| J&M GUL Enterprise Ltd | Real estate | 2018 |
| J&R Smoke Grill Ltd | Hospitality | 2024 |
| J&T UK Investments Ltd | Real estate | 2024 |
| J'S Business Development Consulting Limited | Administrative & support | 2025 |
| J. Dearman & SON Limited | Construction | 2007 |
| J.A. Baron Limited | Construction | 1990 |
| J.A. Rose (Accountants) Limited | Professional & scientific | 1993 |
| J.A.C Greens Ltd | Administrative & support | 2017 |
| J.B.M.J. Limited | Health & social care | 2011 |
| J.C.Fry and Sons Limited | Wholesale & retail | 1962 |
| J.H. Computing Limited | Information & communication | 1987 |
| J.H. Hammond & SON Ltd | Construction | 1999 |
| J.I.T. Property Management Ltd | Real estate | 2014 |
| J.M. Pickering Ltd | Construction | 2003 |
| J.M.Williams Productions Ltd | Information & communication | 2019 |
| J.N.G. Engineering Limited | Manufacturing | 1979 |
| J.Wyatt Digital Limited | Information & communication | 2016 |
| J29 Group Limited | Financial services | 2024 |
| Jabba & Jacob Limited | Households | 2025 |
| Jack Burton Property Services Ltd | Households | 2016 |
| Jack Heathcote Designs Ltd | Professional & scientific | 2020 |
| Jack Joseph Connor Limited | Wholesale & retail | 2003 |
| Jacklin Court Management Company Limited | Households | 1985 |
| Jackson Carpentry & Build Ltd | Construction | 2025 |
| Jackson Developments Limited | Real estate | 1997 |
| Jackson Estates Bournemouth Ltd | Real estate | 2019 |
| Jacl Properties Ltd | Real estate | 2025 |
| Jadaan Consultancy Services Limited | Information & communication | 2003 |
| Jade Bird International UK Limited | Wholesale & retail | 2025 |
| Jade Chapman Collection Ltd | Other services | 2026 |
| Jadow Limited | Real estate | 2020 |
| Jaffray Logistics Ltd | Transport & logistics | 2024 |
| Jagadamba Stores Ltd | Wholesale & retail | 2025 |
| Jagotora Limited | Professional & scientific | 2016 |
| Jaguar Promotions Ltd | Wholesale & retail | 2024 |
| JAH Trade Ltd | Wholesale & retail | 2018 |
| Jahani Holdings Ltd | Real estate | 2025 |
| Jake Baggaley Photographer Ltd | Professional & scientific | 2022 |
| Jamaica UK Rugby C.I.C. | Arts & recreation | 2018 |
| James & James Property Ltd | Real estate | 2023 |
| James Court Right to Manage Company Limited | Real estate | 2012 |
| James Deamer Ltd | Real estate | 2023 |
| James Graham Holdings Limited | Real estate | 2024 |
| James Gray Garden Buildings Limited | Construction | 2020 |
| James Harding Limited | Financial services | 2025 |
| James Longley and Co.Limited | Wholesale & retail | 1967 |
| James Newton Design Ltd | Professional & scientific | 2021 |
| James Southwood Management Ltd | Households | 2005 |
| James Warren Properties Ltd | Real estate | 2025 |
| Jamesmunday Ltd | Professional & scientific | 2019 |
| Jamie’Spaces Ltd | Manufacturing | 2026 |
| Jamin Limited | Administrative & support | 2011 |
| JAMM21 Ltd | Wholesale & retail | 2021 |
| Jammin Homes Ltd | Other services | 2025 |
| Janechi Ventures Limited | Health & social care | 2022 |
| Jangler Ltd | Education | 2023 |
| Janian Lodge RTM Limited | Households | 2004 |
| Janine Pattison Studios Ltd | Professional & scientific | 2010 |
| Jannah Private Ltd | Wholesale & retail | 2025 |
| JAR Cleaning Services Ltd | Water & waste | 2022 |
| Jarmo Ltd | Financial services | 2019 |
| Jaroch Engineering Limited | Construction | 2016 |
| Jasmin MAY Ltd | Administrative & support | 2023 |
| Jasmine Court (Bournemouth) Management Limited | Households | 2003 |
| Jasmine Court (Westbourne) Limited | Households | 2016 |
| Jason Plastering Limited | Construction | 2011 |
| Jasperra Ltd | Real estate | 2025 |
| Jaspers Driver Training Ltd. | Education | 2016 |
| Jaspo Ltd | Wholesale & retail | 2025 |
| Jasu's Indian Street Food Ltd | Hospitality | 2024 |
| Jawfish Distribution Ltd | Wholesale & retail | 2019 |
| JAX Investments Ltd | Real estate | 2020 |
| JAX Property Ltd | Financial services | 2020 |
| JAX Services Ltd | Wholesale & retail | 2019 |
| Jaxxley Homes Limited | Real estate | 2026 |
| Jayne John Limited | Real estate | 2019 |