| Jackson Tuition Services Limited | Education | 2024 |
| Jacob's Prestige Motors Ltd | Wholesale & retail | 2018 |
| Jads Barbers Ltd | Other services | 2024 |
| Jagal Properties Limited | Construction | 2021 |
| Jake Quinlan Architectural Services Ltd | Information & communication | 2018 |
| Jakss & Partners Limited | Wholesale & retail | 2023 |
| Jallow & Co Limited | Other services | 2018 |
| James Hayes Consultancy Ltd | Information & communication | 2025 |
| James Light Limited | Other services | 2021 |
| Jamila Fashion Ltd Ltd | Wholesale & retail | 2026 |
| Janbry Park Ltd | Hospitality | 2026 |
| Jandali Construction Ltd | Construction | 2020 |
| Jarta PM Management Limited | Professional & scientific | 2024 |
| Jask Kavi Ltd | Hospitality | 2016 |
| Jason & D Limited | Transport & logistics | 2018 |
| Jasrw Limited | Construction | 2022 |
| JAX GAS & Heating Limited | Professional & scientific | 2016 |
| Jayan Properties Limited | Real estate | 2025 |
| Jayram Properties Ltd | Real estate | 2021 |
| Jaytech Vision Limited | Information & communication | 2022 |
| JB Transport Specialists Limited | Transport & logistics | 2016 |
| Jbma Consultancy Ltd | Professional & scientific | 2023 |
| JC Physio Limited | Other services | 2024 |
| JC Plumbing Ltd | Construction | 2015 |
| Jcdn Ltd | Construction | 2026 |
| Jchaub Ltd | Water & waste | 2022 |
| JCO Wholesale Ltd | Wholesale & retail | 2025 |
| Jcpp Holdings Ltd | Financial services | 2025 |
| JD & Sons Roofing & Building Ltd | Construction | 2016 |
| JD Scenery Ltd | Construction | 2023 |
| JE Retail Solutions Limited | Information & communication | 2019 |
| Jeffreeze Refrigeration Ltd | Manufacturing | 2014 |
| Jeffrey Trading Limited | Construction | 2024 |
| Jehoida UK Limited | Real estate | 2025 |
| Jeremy Isaac Ltd | Arts & recreation | 2019 |
| JET MOT Centre Limited | Wholesale & retail | 2016 |
| Jet&M Construction Ltd | Construction | 2023 |
| Jetspark Ltd | Information & communication | 2020 |
| Jewellery by Natt Ltd | Wholesale & retail | 2022 |
| JG Fashions Limited | Wholesale & retail | 2019 |
| JG Power Steering Ltd | Wholesale & retail | 2025 |
| Jgas Holdings Ltd | Information & communication | 2025 |
| JHJ Foods Ltd | Hospitality | 2026 |
| JHP Construction Limited | Construction | 2026 |
| Jhsheng Trading Co., Ltd | Administrative & support | 2023 |
| JHY Property Ltd | Real estate | 2023 |
| Jiangsu Jinfa Chemical Fibre Equipment Co., Ltd | Wholesale & retail | 2023 |
| Jiangsu Xiangchuan Rope Technology Co., Ltd | Administrative & support | 2022 |
| Jiayu International Trading Co., Ltd | Wholesale & retail | 2024 |
| Jigsaw Industries Limited | Construction | 2018 |
| Jilka Limited | Information & communication | 2025 |
| JIM Flynn Consultancy Ltd | Real estate | 2020 |
| Jining Jihe Import and Export Co., Ltd. | Administrative & support | 2023 |
| Jinkang Automobile Co., Limited | Administrative & support | 2025 |
| Jinwon International Limited | Administrative & support | 2020 |
| Jivi Kapoor Limited | Wholesale & retail | 2020 |
| JJ Auto Prestige Limited | Wholesale & retail | 2017 |
| JJA Foods Limited | Wholesale & retail | 2023 |
| JK Drainage Limited | Professional & scientific | 2018 |
| JK Homme (UK) Ltd | Construction | 2013 |
| JKS Accounting and Taxation Limited | Professional & scientific | 2020 |
| JLJ International Transportation Co., Ltd | Extraterritorial | 2022 |
| JMA Parent Co Limited | Real estate | 2021 |
| JMC Home Improvements Limited | Construction | 2014 |
| JMC Lofts & Extensions Ltd | Construction | 2017 |
| JMS Drylining Limited | Construction | 2026 |
| JMS Recruitment Limited | Administrative & support | 2010 |
| JMS Recruitment SVC Ltd | Administrative & support | 2022 |
| JN PVT. Ltd | Wholesale & retail | 2022 |
| JN12SNN PTY Ltd | Real estate | 2017 |
| JND GZ Co., Ltd | Wholesale & retail | 2023 |
| JNF Marketing Ltd | Manufacturing | 2022 |
| Jobling Windows & Doors Ltd | Construction | 2017 |
| Jogo Media Limited | Professional & scientific | 2020 |
| John Brown Engineering Ltd | Energy | 2019 |
| John Maher & Sons Limited | Other services | 2003 |
| John Sterling Group Ltd | Professional & scientific | 2026 |
| Johnstons Property Solutions Limited | Construction | 2024 |
| JON Edwards Repair Ltd | Manufacturing | 2015 |
| Joncaro Investments Limited | Households | 2012 |
| Joonuo International Co., Ltd. | Extraterritorial | 2023 |
| Joshi Distribution Limited | Wholesale & retail | 2026 |
| Joy Q Technology Co., Ltd. | Administrative & support | 2020 |
| JP Electrical London Limited | Construction | 2021 |
| JP Waterproofing Ltd | Construction | 2022 |
| JPS & Co Property Services Ltd | Construction | 2025 |
| Jpspurchase Ltd | Real estate | 2018 |
| Jpsrent Ltd | Households | 2018 |
| JR Autos Limited | Wholesale & retail | 2014 |
| JR Carpet & Flooring Limited | Construction | 2019 |
| JR Sagoo Limited | Health & social care | 2015 |
| JRD Agri Machinery Ltd | Wholesale & retail | 2014 |
| JRP Accountants Ltd | Professional & scientific | 2016 |
| JRP Building and Carpentry Ltd | Construction | 2025 |
| JS Adviser Ltd | Professional & scientific | 2019 |
| JS Mechanical Limited | Construction | 2018 |
| JSA Connect Limited | Information & communication | 2026 |
| JSA Property Investments Limited | Real estate | 2023 |
| JSC Tactical Ltd | Wholesale & retail | 2023 |
| Jsfx Ltd | Construction | 2019 |