| JA PVT Limited | Hospitality | 2016 |
| JAA Logistics Limited | Transport & logistics | 2019 |
| JAB Holdings Limited | Professional & scientific | 2015 |
| JAB Products Limited | Manufacturing | 2016 |
| Jaba Holdings Limited | Hospitality | 2016 |
| Jaba Limited | Real estate | 2016 |
| Jaber Limited | Wholesale & retail | 2010 |
| JAC Estates Limited | Wholesale & retail | 2007 |
| Jack & ZOE Ltd | Other services | 2015 |
| Jackie Nails Limited | Other services | 2025 |
| Jacobs & Partners Ltd | Transport & logistics | 2023 |
| Jacobs and Partners Services Ltd | Real estate | 2025 |
| Jacobs Renovations Ltd | Construction | 2023 |
| Jade Lavender Nails Limited | Other services | 2025 |
| Jade Law Solicitors Limited | Professional & scientific | 2025 |
| Jade M RAI Ltd | Wholesale & retail | 2023 |
| Jade Toner Ltd | Wholesale & retail | 2022 |
| Jadetech Limited | Information & communication | 2020 |
| Jaes Dadson Limited | Manufacturing | 2024 |
| Jaffna Taste Limited | Hospitality | 2021 |
| Jaft Ltd | Wholesale & retail | 2024 |
| JAHSGR8 Company Limited | Transport & logistics | 2023 |
| Jakala Consulting Ltd | Professional & scientific | 2024 |
| Jakaya X Ltd | Information & communication | 2021 |
| Jalal & Sons Investment Ltd | Real estate | 2019 |
| Jalaram Brahm Ltd | Wholesale & retail | 2015 |
| Jaleco Ltd. | | 1991 |
| Jallo N Jallo Ltd | Construction | 2015 |
| JAM Music Project Limited | Information & communication | 2025 |
| Jambo Care Ltd | Transport & logistics | 2023 |
| James Gardner Trees Ltd | Administrative & support | 2023 |
| Jamesbrow Limited | Administrative & support | 1984 |
| Jamie Nichols - Emcee & Magician Limited | Arts & recreation | 2023 |
| Jamiejed Limited | Information & communication | 2023 |
| Jamjar Group Ltd | Wholesale & retail | 2022 |
| Jamm Exchange CIC | Information & communication | 2026 |
| Jamry Solutions Ltd | Transport & logistics | 2024 |
| Jams Flooring & Co Ltd | Construction | 2024 |
| Jane Louise Hirst Limited | Professional & scientific | 2015 |
| Janen Limited | Health & social care | 2021 |
| January Developments Ltd | Real estate | 2017 |
| Jape Consulting Limited | Information & communication | 2002 |
| Jasnoor Food and Wine Limited | Wholesale & retail | 2022 |
| Jaspa Enfield Ltd | Hospitality | 2013 |
| Jaspa Technology Limited | Information & communication | 2019 |
| Jaspol Ltd | Wholesale & retail | 2012 |
| Jaspra Healthcare Limited | Health & social care | 2022 |
| JAV GEN Power Solution Ltd | Wholesale & retail | 2025 |
| Jave Investments & Real Estate Limited | Real estate | 2019 |
| JAY & C Ltd | Real estate | 2025 |
| JAY & RAY Investments Ltd | Real estate | 2024 |
| Jay's Homecare Limited | Health & social care | 1998 |
| Jay's Nanny Ltd | Health & social care | 2024 |
| Jayanti & Lata Ltd | Real estate | 2024 |
| Jaycroft Management Company Limited | Households | 1984 |
| Jaydy Nails Limited | Other services | 2016 |
| Jayne Louise Street Limited | Health & social care | 2017 |
| Jaywess Properties Limited | Real estate | 2026 |
| JB Chase Cleaning Services Ltd | Administrative & support | 2024 |
| Jbily Ltd. | Extraterritorial | 2011 |
| Jcmbookkeeping Ltd | Professional & scientific | 2025 |
| JD Kitchen Worktops & Tiling Ltd | Manufacturing | 2026 |
| JD Mahmout Ltd | Construction | 2025 |
| JD Metalworks Ltd | Manufacturing | 2016 |
| JD UK Properties Limited | Real estate | 2017 |
| JDB & Sons Holdings Ltd | Financial services | 2021 |
| JDE Engineering Ltd | Professional & scientific | 2026 |
| Jdgoldson Ltd | Real estate | 2026 |
| JDH Resources Ltd | Professional & scientific | 2021 |
| JDI Instruction Ltd | Education | 2004 |
| JDK Properties UK Ltd | Real estate | 2007 |
| Jdlux Build Ltd | Construction | 2026 |
| JDP Chase Ltd | Financial services | 2021 |
| Jeans Boulton Seymour Limited | Other services | 2004 |
| Jeans Hairstylists Limited | Other services | 2001 |
| Jefferson Wright Services Ltd | Construction | 2014 |
| Jeffstar Properties Limited | Real estate | 2021 |
| JEL Property Solutions Ltd | Real estate | 2023 |
| Jema Assessments Ltd | Health & social care | 2026 |
| Jemska Ltd | Construction | 2025 |
| Jemz Caribbean Ltd | Hospitality | 2016 |
| Jenevi Educare Limited | Education | 2023 |
| Jeng Noodle Ltd | Hospitality | 2023 |
| Jennor Timber Co. Limited | Wholesale & retail | 1980 |
| Jennova Consulting Limited | Information & communication | 2013 |
| Jenny’S Nails and Beauty Limited | Other services | 2018 |
| Jensco Ltd | Real estate | 2016 |
| JEP Media Ltd | Information & communication | 2024 |
| Jerell Ecotech Limited | Information & communication | 2025 |
| Jerk + Grind Airstream Limited | Hospitality | 2023 |
| Jerk + Grind Limited | Hospitality | 2023 |
| Jesjode Consultants Ltd | Professional & scientific | 2020 |
| Jesmardav Ltd | Hospitality | 2016 |
| JET Essentials Ltd | Transport & logistics | 2026 |
| Jeveoc Ltd | Professional & scientific | 2024 |
| Jewellery Consultancy Services Limited | Wholesale & retail | 2002 |
| Jewels Travel Management Limited | Administrative & support | 2023 |
| Jeye Communications Limited | Information & communication | 2025 |
| Jfgc Limited | Administrative & support | 2021 |
| JFJ Property Services Ltd | Households | 2023 |