| IW Solutions Ltd | Real estate | 2016 |
| J & H Lighting Limited | Information & communication | 2009 |
| J F Vehicle Services Limited | Wholesale & retail | 2018 |
| J Foster Associates Ltd | Administrative & support | 2003 |
| J G Carey Builds Ltd | Construction | 2016 |
| J G Truty Sprinkler Installations Limited | Construction | 2008 |
| J M D W Ltd | Construction | 2021 |
| J M S Food & Wine Ltd | Wholesale & retail | 2019 |
| J Parker Electrics Limited | Construction | 2018 |
| J Rusby Consulting Limited | Professional & scientific | 2024 |
| J S & Sons Accountants Limited | Professional & scientific | 2014 |
| J Santos Ltd | Transport & logistics | 2026 |
| J Scollan & Co Ltd | Professional & scientific | 2019 |
| J Spraggon Global Scenery Ltd | Construction | 2018 |
| J W Mtrans Ltd | Transport & logistics | 2018 |
| J W Utility Services Ltd | Construction | 2022 |
| J&L Transport Ltd | Transport & logistics | 2025 |
| J&R Kitchen Installers Ltd | Construction | 2015 |
| J&T Property Investment Limited | Real estate | 2025 |
| J.C. Construction Projects Ltd | Extraterritorial | 2010 |
| J.E Souper Soups Limited | Manufacturing | 2025 |
| J.G. Electrical Limited | Construction | 1999 |
| J.I.R Property Ltd | Real estate | 2024 |
| J.J.Hall Building Services Ltd | Construction | 2013 |
| J.J.M. Taxis and Zulu Cars Ltd | Transport & logistics | 2008 |
| J.Kep Ltd | Wholesale & retail | 2024 |
| J.R. Hill & Sons Limited | Other services | 2002 |
| J3 Consult Limited | Administrative & support | 2024 |
| Jaar Way Ltd | Construction | 2019 |
| Jafeek Ltd | Extraterritorial | 2026 |
| Jagco Property Management Ltd | Real estate | 2025 |
| Jake Curtis Photography Limited | Arts & recreation | 2010 |
| Jakks Pacific (UK) Ltd | Wholesale & retail | 2008 |
| Jale's Clinic Limited | Other services | 2019 |
| Jalo Logistics Ltd | Transport & logistics | 2025 |
| JAM HC Ltd | Financial services | 2025 |
| James & Ford Decorating & Interior Design Services Ltd | Construction | 2022 |
| James for Drains Ltd | Water & waste | 2023 |
| Jamie Cooke Electrical Ltd | Construction | 2016 |
| Jamie Cooke Electrical Services LLP | | 2013 |
| Jamie's Rigging Services Limited | Construction | 2016 |
| Jamm Resources Limited | Water & waste | 2019 |
| Jasi Consults Limited | Transport & logistics | 2009 |
| Jason Francis Sport Ltd | Real estate | 2021 |
| JB Elephant and Castle Limited | Wholesale & retail | 2025 |
| JC Maison Limited | Real estate | 2020 |
| JCH Garden Services Limited | Administrative & support | 2019 |
| JCL Lordan Properties Ltd | Real estate | 2019 |
| Jcsa Ltd | Real estate | 2021 |
| JD Advanced Building Services Limited | Construction | 2024 |
| JD Precision Laser Engraving Ltd | Wholesale & retail | 2025 |
| JD Property & Electrical Services Limited | Construction | 2015 |
| JDL Taverns Ltd | Hospitality | 2026 |
| JDM Electrical and Network Limited | Construction | 2023 |
| JDT Lighting Ltd | Construction | 2026 |
| Jealotts 1962 Limited | Extraterritorial | 2014 |
| Jealotts Hill Community Landshare CIC | Agriculture & fishing | 2023 |
| Jeas Communications Limited | Other services | 2023 |
| Jeas Group Limited | Other services | 2018 |
| Jeas Property Holdings Limited | Real estate | 2026 |
| Jeecks Ventures Ltd | Financial services | 2014 |
| Jennifer Allen Design Ltd | Professional & scientific | 2025 |
| Jennifer Mahon Ltd | Wholesale & retail | 2025 |
| JF Crewe & Co. Limited | Construction | 2020 |
| Jiapads Ltd | Real estate | 2016 |
| Jimmy Demetri Limited | Real estate | 2016 |
| Jingle Global Ltd | Professional & scientific | 2011 |
| Jistina Fashions Ltd | Health & social care | 2013 |
| Jive Bunny Limited | Arts & recreation | 2013 |
| JJ1TRANSPORT Ltd | Transport & logistics | 2023 |
| Jjbee Limited | Health & social care | 2024 |
| JJH Pest Control Limited | Administrative & support | 2020 |
| JJH Supplies Ltd | Wholesale & retail | 2023 |
| JJM Real Estate Limited | Wholesale & retail | 2025 |
| JK & Associates Therapy Services Ltd. | Health & social care | 2013 |
| JK Global Consulting Limited | Administrative & support | 2024 |
| JKK Chan Ltd | Professional & scientific | 2023 |
| JKL Family Holdings Limited | Financial services | 2023 |
| JKR Automation Ltd | Professional & scientific | 2019 |
| Jktranstech Ltd | Wholesale & retail | 2024 |
| JL Home Edit Ltd | Administrative & support | 2024 |
| JL Precision Fabrication Ltd | Professional & scientific | 2025 |
| JM Auto Services Ltd | Professional & scientific | 2022 |
| JM Cleaning Services Ltd | Administrative & support | 2025 |
| JM Good Limited | Arts & recreation | 2011 |
| JM Mont MAR Holdings Limited | Professional & scientific | 2025 |
| Jmec Limited | Construction | 2018 |
| JMF Windows & Doors Ltd | Construction | 2024 |
| JMG Polo Limited | Arts & recreation | 2023 |
| Jmjm Holdings Ltd | Hospitality | 2025 |
| Jmpk Ocean Business Limited | Administrative & support | 2022 |
| Jmva Limited | Administrative & support | 2014 |
| JN Support Ltd | Education | 2026 |
| JO Billing Creative Ltd | Administrative & support | 2020 |
| JOB Boards Media Ltd | Professional & scientific | 2013 |
| Jobstin Limited | Transport & logistics | 2025 |
| Jodende Ltd | Health & social care | 2020 |
| Jodie Mitchell Photography Ltd | Professional & scientific | 2026 |
| JOE Cartledge Limited | Agriculture & fishing | 1962 |
| Joeyjanelle Ltd | Health & social care | 2025 |