| Jeees Social Care Ltd | Health & social care | 2021 |
| Jeegoo Ltd | Education | 2024 |
| Jeff Carter Ltd | Wholesale & retail | 2010 |
| Jeff H Services Ltd | Information & communication | 2019 |
| Jeff Madine Holdings Limited | Financial services | 2011 |
| Jefferyhills Ltd | Health & social care | 2018 |
| JEG Waste Ltd | Water & waste | 2024 |
| Jehangir & Sons Ltd | Wholesale & retail | 2023 |
| Jehangir Restaurant Ltd | Hospitality | 2018 |
| Jejuxcosmetics Limited | Manufacturing | 2020 |
| Jelcon Limited | Construction | 2017 |
| Jellicoe Holdings Ltd | Financial services | 2024 |
| Jellis & Jellis Limited | Agriculture & fishing | 2023 |
| Jellyfish Livewire Limited | Manufacturing | 2003 |
| JEM Care Group Limited | Health & social care | 2026 |
| JEM Electrical Ltd | Construction | 2022 |
| Jems Group Southern Ltd | Construction | 2024 |
| JEN Financial Limited | Financial services | 2019 |
| JEN Prop Ltd | Real estate | 2026 |
| Jeni Susan Shergold Ltd | Extraterritorial | 2022 |
| Jenks Solutions Ltd | Professional & scientific | 2017 |
| Jenny Hadland & Company Limited | Administrative & support | 2012 |
| Jensen Court Management Company Limited | Households | 1994 |
| Jensen Property Ltd | Real estate | 2013 |
| Jensen Property Management Ltd | Real estate | 2021 |
| Jenvicity News Ltd | Wholesale & retail | 2025 |
| Jeremy Gailor Plumbing and Heating Ltd | Construction | 2016 |
| Jeremy Snook Ltd | Construction | 2025 |
| Jeremy Wingate Limited | Wholesale & retail | 2000 |
| Jescon Ltd | Wholesale & retail | 2015 |
| Jess MAE PT Womens FAT Loss Coach Ltd | Other services | 2023 |
| Jessica Lovett Design Limited | Professional & scientific | 2022 |
| Jessica Rose Moreton Limited | Real estate | 2022 |
| Jessica Winter Properties Ltd | Real estate | 2020 |
| JET PC Properties Ltd | Real estate | 2019 |
| Jetag Limited | Manufacturing | 2021 |
| Jetstream Drain Cleaning Limited | Water & waste | 2015 |
| Jetworks Limited | Manufacturing | 2000 |
| Jewel & Sword Ltd | Transport & logistics | 2018 |
| Jewel Junction Ltd | Wholesale & retail | 2025 |
| Jewell Holdings Ltd | Wholesale & retail | 2018 |
| Jewell Property Services Limited | Real estate | 2020 |
| Jewells GAS Services Limited | Construction | 2012 |
| Jewels Premier Properties Ltd | Hospitality | 2016 |
| Jezreel Transports Ltd | Transport & logistics | 2023 |
| JF Auto Cars Ltd | Wholesale & retail | 2025 |
| JF Garden Services Limited | Administrative & support | 2019 |
| JF Medical Consult Ltd Ltd | Other services | 2016 |
| JF Online Ltd | Administrative & support | 2018 |
| JF Photographer Limited | Professional & scientific | 2023 |
| JF RN Investments Ltd | Hospitality | 2025 |
| JF Transport Consultancy Ltd | Transport & logistics | 2024 |
| JF Transport Ltd | Transport & logistics | 2021 |
| JFB Cleaning Ltd | Administrative & support | 2025 |
| JFG Construction Solutions Limited | Education | 2024 |
| JFS Cafe Ltd | Hospitality | 2024 |
| JFS Electronics Ltd | Information & communication | 2025 |
| JFS Holdings Southern Limited | Other services | 2025 |
| JG Accommodation Ltd | Real estate | 2023 |
| JG and SON Carpentry Limited | Construction | 2018 |
| JG Communication Services Ltd | Administrative & support | 2002 |
| JG Installation Maintenance Ltd | Construction | 2023 |
| JG Projects 01 Limited | Construction | 2021 |
| JG Projects Associates Ltd | Other services | 2023 |
| JG Property Services Limited | Construction | 2016 |
| JG Tennis Coaching Limited | Arts & recreation | 2018 |
| JGC Technical Recruitment Limited | Administrative & support | 2017 |
| JGH Prop Serv Ltd | Households | 2022 |
| Jglbeers Ltd | Hospitality | 2022 |
| JGM Associates Limited | Real estate | 2020 |
| JGM Commercial Ltd | Construction | 2023 |
| JH Consulting (Europe) Ltd | Other services | 2007 |
| JH Estate Developments Ltd | Construction | 2025 |
| JH Frearson Limited | Professional & scientific | 2009 |
| JH SVG Capital Ltd | Professional & scientific | 2026 |
| JHB (Bristol) Ltd | Wholesale & retail | 2018 |
| JHB Cardiff Ltd | Wholesale & retail | 2021 |
| JHB Exchange Limited | Wholesale & retail | 2016 |
| JHB Property Ltd | Real estate | 2017 |
| JHB Technology Limited | Wholesale & retail | 2014 |
| JHJ Fitness Ltd | Arts & recreation | 2025 |
| JHL Property Ltd | Real estate | 2022 |
| JI Chicken Southampton Limited | Hospitality | 2021 |
| JI Day Eatery Ltd | Hospitality | 2018 |
| JIA Property Limited | Real estate | 2016 |
| Jigil Ltd | Wholesale & retail | 2026 |
| Jigsaw Pre-School (Western Wards) | Education | 2008 |
| Jigsaw Property Management South Ltd | Real estate | 2026 |
| Jilit Limited | Transport & logistics | 2023 |
| JIM Muir Ltd | Construction | 2016 |
| Jimbob Property Management Ltd | Households | 2026 |
| Jimmy Read Limited | Extraterritorial | 2013 |
| Jimmys Barbering Ltd | Other services | 2020 |
| JIN Feng Ltd | Hospitality | 2011 |
| JIN LI Hampshire Limited | Wholesale & retail | 2023 |
| Jindalai Ltd | Hospitality | 2024 |
| Jirehouse Capital Finance Limited | Financial services | 2005 |
| Jirehouse Partners LLP | | 2012 |
| Jirehouse Trustees Ltd | Financial services | 2004 |
| Jirl Ltd | Construction | 2025 |