| Jasu Food & Wines Ltd | Wholesale & retail | 2023 |
| Jasveen Investments Ltd | Real estate | 2019 |
| Jasvinder Kandola Limited | Health & social care | 2017 |
| Jasvir Developments Limited | Real estate | 2023 |
| Jaswant Singh Gill Ltd | Construction | 2016 |
| Jatin Nandkishor Chawla Ltd | Construction | 2021 |
| Jawandha UK Limited | Transport & logistics | 2025 |
| JAX Rigging Film and TV Services Ltd | Construction | 2023 |
| JAY Grewal Investments Ltd | Construction | 2024 |
| Jay's Transport Ltd | Transport & logistics | 2016 |
| Jayesh Estates Ltd | Real estate | 2023 |
| Jayjeffect Ltd | Other services | 2025 |
| Jays Property Services Ltd | Real estate | 2022 |
| Jaysavy Consultancy Limited | Information & communication | 2015 |
| JAZ Logistics Limited | Transport & logistics | 2024 |
| Jazz UK Transport Ltd | Transport & logistics | 2022 |
| Jazzmyra Ltd | Real estate | 2024 |
| Jazzmyra Properties Ltd | Real estate | 2023 |
| JB Design & Build Ltd | Construction | 2026 |
| JB Hayes LLP | | 2026 |
| JB Home Improvement Ltd | Construction | 2026 |
| JB Management Consultant Ltd | Professional & scientific | 2019 |
| JB UK Services Ltd | Transport & logistics | 2025 |
| JB Wholesale Ltd | Wholesale & retail | 2024 |
| Jb&B Ltd | Wholesale & retail | 2020 |
| Jbains Ltd | Transport & logistics | 2018 |
| JBL Developers Limited | Construction | 2024 |
| Jbnn Ltd | Information & communication | 2026 |
| JBR Transportation Ltd | Transport & logistics | 2025 |
| JBS Spares Ltd | Wholesale & retail | 2025 |
| JCP Jewellery Claims Ltd | Professional & scientific | 2009 |
| JD Shopfront and Shutters Limited | Construction | 2017 |
| JDD Construction Solutions Ltd | Construction | 2025 |
| Jdfruits Limited | Wholesale & retail | 2020 |
| JDR Ltd | Transport & logistics | 2016 |
| Jebex Limited | Professional & scientific | 2004 |
| Jeenap Limited | Health & social care | 2024 |
| Jeet & Preet Ltd | Real estate | 2025 |
| Jeet Beauty Parlour Ltd | Other services | 2024 |
| Jeet Fashions Limited | Wholesale & retail | 2003 |
| Jeet International (UK) Limited | Wholesale & retail | 2011 |
| Jeet Property Ltd | Real estate | 2019 |
| Jeeta Manak Transport Ltd | Transport & logistics | 2025 |
| Jeevan Construction Ltd | Construction | 2016 |
| Jeevat Properties Ltd | Real estate | 2023 |
| Jelibean Inc Ltd | Wholesale & retail | 2015 |
| Jemima MSR Properties Ltd | Real estate | 2024 |
| Jen&Den Ltd | Transport & logistics | 2021 |
| Jenny Louise Webster Limited | Extraterritorial | 2024 |
| Jesse Mcqueen Limited | Transport & logistics | 2017 |
| JEY IT Solutions London Ltd | Information & communication | 2024 |
| JF Courier Services Limited | Transport & logistics | 2019 |
| JF Motorcycle Ltd | Administrative & support | 2024 |
| JFC (MCR) Ltd | Hospitality | 2018 |
| JFC (UK) Limited | Wholesale & retail | 1992 |
| Jflame&Co Ltd | Construction | 2025 |
| JFR Properties Limited | Real estate | 2020 |
| JFS London Limited | Wholesale & retail | 2005 |
| JG SSC Limited | Education | 2022 |
| Jgai Consulting Ltd | Professional & scientific | 2026 |
| JGJ Global Ltd | Other services | 2019 |
| JGJ Motors Ltd | Wholesale & retail | 2025 |
| Jhajj Construction Ltd | Construction | 2026 |
| Jhall Properties Ltd | Real estate | 2025 |
| Jhally Home Improvement Ltd | Construction | 2019 |
| Jhand Construction Ltd | Other services | 2013 |
| Jhand Projects Ltd | Construction | 2025 |
| Jhand Properties Ltd | Real estate | 2023 |
| JHB Adventures Limited | Administrative & support | 2014 |
| JHG Trading Limited | Wholesale & retail | 2025 |
| Jhmd Asset Management Limited | Real estate | 2016 |
| Jigsaw Films London Ltd | Information & communication | 2019 |
| Jinny's Health & Beauty World Ltd | Hospitality | 2012 |
| JIO Consultants Ltd | Professional & scientific | 2023 |
| JIO Property Ltd | Real estate | 2026 |
| JIT Builders Ltd | Construction | 2020 |
| JIT Construction Limited | Construction | 2020 |
| JIT Transport Ltd | Transport & logistics | 2014 |
| Jit's Hauliers Ltd | Transport & logistics | 2018 |
| JJ Building &Decorating Limited | Construction | 2018 |
| JJ Home Development Ltd | Real estate | 2025 |
| JJ Law Chambers Ltd | Professional & scientific | 2017 |
| JJ Sandhu Construction Ltd | Construction | 2020 |
| JJ Structure & Roofing Ltd | Construction | 2022 |
| JJ Transport Ltd | Transport & logistics | 2025 |
| Jjmc Property Group Ltd | Real estate | 2024 |
| JJV Properties Limited | Real estate | 2005 |
| JK Conway Homes Ltd | Real estate | 2023 |
| JK Devgun Properties Ltd | Real estate | 2021 |
| JK Digital Fashion Limited | Wholesale & retail | 2018 |
| JK Essence Ltd | Wholesale & retail | 2026 |
| JK Express Supermarket Ltd | Other services | 2025 |
| JK Fine Finish Ltd | Construction | 2024 |
| JK Kitchen & Bedroom Ltd | Construction | 2022 |
| JK Local Wines Ltd | Wholesale & retail | 2017 |
| JK Shop Front and Shutters Limited | Construction | 2008 |
| JK Top Ltd | Wholesale & retail | 2024 |
| Jk's Studio Ltd | Information & communication | 2025 |
| JK02 ALE Ltd | Hospitality | 2025 |
| JK13 Ltd | Real estate | 2022 |