| JSE Engineering Limited | Professional & scientific | 2023 |
| JSJ Autos Ltd | Wholesale & retail | 2022 |
| JSL Wholesale Limited | Wholesale & retail | 2021 |
| JSM Property Services (UK) Ltd | Construction | 2011 |
| JSO Accountancy Ltd | Professional & scientific | 2016 |
| JSO Electrical Limited | Construction | 2022 |
| Jsooni Ltd | Professional & scientific | 2022 |
| Jsrb Event Management Ltd | Administrative & support | 2022 |
| JT (Bristol) Limited | Administrative & support | 1979 |
| JT Aspirations Ltd | Professional & scientific | 2023 |
| JT Asset Property Management Limited | Real estate | 2021 |
| JT Bathroom & Home Solutions Ltd | Professional & scientific | 2024 |
| JT Building Contractors Ltd | Construction | 2023 |
| JT Carpentry & Build Ltd | Construction | 2021 |
| JT Carpentry (SW) Limited | Manufacturing | 2022 |
| JT Ceilings & Partitions Ltd | Construction | 2021 |
| JT Commercial Investments Ltd | Real estate | 2015 |
| JT Merchandise Ltd | Wholesale & retail | 2023 |
| JT Portfolio Ltd | Real estate | 2020 |
| JT Property Services SW Ltd | Construction | 2012 |
| JT Studio Limited | Professional & scientific | 2018 |
| JTB Orthopaedics Ltd | Health & social care | 2025 |
| JTD Solar Ltd | Construction | 2024 |
| Jtdn Ltd | Health & social care | 2017 |
| Jtee Computers (UK) Ltd | Professional & scientific | 2014 |
| JTF Electrical Services Ltd | Construction | 2020 |
| JTG Props Ltd | Real estate | 2020 |
| Jthirteen Limited | Financial services | 2023 |
| Jthos Limited | Professional & scientific | 2014 |
| JTI Partners Limited | Wholesale & retail | 2024 |
| JTK (Leasing) Ltd | Real estate | 2021 |
| JTK Construction Ltd | Real estate | 2016 |
| Jtlovers Limited | Wholesale & retail | 2026 |
| JTS Saddlery Limited | Wholesale & retail | 2015 |
| Jtsm Transport Ltd | Transport & logistics | 2024 |
| Jtsquared Ltd | Real estate | 2023 |
| Jtsquared Projects Ltd | Professional & scientific | 2025 |
| Jtti Enterprises Limited | Wholesale & retail | 2017 |
| JU KY Ltd | Hospitality | 2026 |
| JUA (Bristol) Ltd | Wholesale & retail | 2013 |
| Jubb Clews Ltd | Professional & scientific | 2000 |
| Jubilee Crescent Management Company Limited | Households | 2026 |
| Jubilee Flats Management Company Ltd | Households | 2025 |
| Jubilee Roofing Limited | Construction | 2008 |
| Juda Liquideur Ltd | Other services | 2021 |
| Jude Electricals Ltd | Construction | 2016 |
| Judith BM Care Ltd | Extraterritorial | 2022 |
| Judroneil Limited | Health & social care | 2020 |
| Judy U.K Ltd | Construction | 2023 |
| Juesi Limited | Hospitality | 2022 |
| Juggling Inferno Ltd | Arts & recreation | 2014 |
| Juggy Ltd | Financial services | 2024 |
| Jugo Digital Limited | Information & communication | 2021 |
| Jugo Holdco Limited | Financial services | 2023 |
| Juhu Limited | Transport & logistics | 2016 |
| Juice Community Project Community Interest Company | Health & social care | 2007 |
| Juice ME Ltd | Hospitality | 2026 |
| Juice Tactics Limited | Information & communication | 2014 |
| Juicy Face Ltd | Other services | 2020 |
| Juju Sounds Ltd | Information & communication | 2020 |
| Juke and Scarlet Ltd | Other services | 2012 |
| Julenbeauty Ltd | Manufacturing | 2020 |
| Julia Cleaning Ltd | Transport & logistics | 2019 |
| Julia Coelho Medical Aesthetics Ltd. | Health & social care | 2015 |
| Julia Thomas HR Consultancy Ltd | Administrative & support | 2021 |
| Julian Blackwell Ltd | Professional & scientific | 2022 |
| Julian Burr Events Limited | Arts & recreation | 2026 |
| Julian Court (Management) Limited | Households | 1967 |
| Julian James Photography Limited | Professional & scientific | 2003 |
| Julian Telling Consulting Limited | Administrative & support | 2008 |
| Julie Gazzard Swim Academy Limited | Education | 2021 |
| Julie Hunt Advertising Limited | Professional & scientific | 2002 |
| Julie K Care Limited | Health & social care | 2018 |
| Julie Osborn Psychology Limited | Health & social care | 2021 |
| Julie's House Management Limited | Real estate | 2008 |
| July Two One Ltd | Public administration | 2024 |
| Julébeauty Limited | Manufacturing | 2026 |
| Juma Catering Bristol Ltd | Hospitality | 2021 |
| Jumanji Clearance & Groundworks Ltd | Administrative & support | 2025 |
| Jumbo International Limited | Extraterritorial | 1995 |
| Jumby Limited | Real estate | 2016 |
| Jumeirah Ltd | Wholesale & retail | 2023 |
| Jumma Catering Ltd | Hospitality | 2017 |
| Jump N Joy Castles Ltd | Administrative & support | 2024 |
| Jump Street Limited | Arts & recreation | 2014 |
| Jump Street Management Ltd | Arts & recreation | 2015 |
| Jumpfit U.K Ltd | Other services | 2019 |
| Jumpin Surrey Limited | Arts & recreation | 2018 |
| Jumping Joint Limited | Information & communication | 2007 |
| Jumpstart Food and Fitness CIC | Hospitality | 2017 |
| Junada Ltd | Hospitality | 2025 |
| Junction Terrace Management Company Limited | Households | 2003 |
| Junction Three Consultancy Ltd | Professional & scientific | 2021 |
| JUNCTION360 Ltd | Administrative & support | 2024 |
| JUNCTION3WORKSHOPS Ltd | Administrative & support | 2003 |
| June Glow Ltd | Other services | 2023 |
| June Skincare Ltd | Extraterritorial | 2020 |
| Juneb Ltd | Extraterritorial | 2021 |
| Jungle Green MRC Limited | Professional & scientific | 2002 |
| Jungle Syndicate Ltd | Wholesale & retail | 2026 |