| J.Dynamic Care Ltd | Health & social care | 2019 |
| J.E. Gibbings & Sons Limited | Construction | 1996 |
| J.E. Sheppard & Sons (Sawmills) | Real estate | 1942 |
| J.E.C Mechanical Services Ltd | Construction | 2022 |
| J.F Variable Ltd | Information & communication | 2015 |
| J.H. Abraham & Sons (Bristol) Limited | Wholesale & retail | 1964 |
| J.H. Steward (Bisley) Limited | Health & social care | 1972 |
| J.I. Conversions Limited | Construction | 2019 |
| J.J. Digits Ltd | Real estate | 2017 |
| J.J. Thompson (Orthodontic Appliances) Limited | Manufacturing | 1964 |
| J.Kamara Limited | Manufacturing | 2014 |
| J.L. Hall Properties Limited | Real estate | 2018 |
| J.M.P. Precision Engineering Limited | Manufacturing | 2001 |
| J.P Carpentry & Construction Services Ltd | Construction | 2020 |
| J.P Tyrrell Development Ltd | Construction | 2023 |
| J.P. Fannon & SON (Contractors) Limited | Construction | 1974 |
| J.P.Movements Ltd | Transport & logistics | 2025 |
| J.R.B Garages Ltd | Real estate | 2025 |
| J.S Hire (Bristol) Limited | Wholesale & retail | 2016 |
| J.S.Tattoo Ltd | Arts & recreation | 2025 |
| J.T.Baylis & Company Limited | Construction | 1957 |
| J.W. Nichols (Poultry) Limited | Agriculture & fishing | 1974 |
| J13 Holdings Limited | Financial services | 2022 |
| J25 Property Investment Ltd | Real estate | 2020 |
| J2H Limited | Real estate | 2004 |
| J2K Capital Ltd | Real estate | 2024 |
| J2W Food Ltd | Hospitality | 2021 |
| J2W Invest Limited | Real estate | 2025 |
| J4 Developments SW Ltd | Real estate | 2021 |
| J4 Projects Limited | Professional & scientific | 2014 |
| J43 Ltd | Information & communication | 2025 |
| J9 Projects Ltd | Construction | 2021 |
| JA Bristol Limited | Construction | 2024 |
| JA Financial Ltd | Financial services | 2022 |
| JA Investment Properties Ltd | Real estate | 2024 |
| JA Supplies Limited | Wholesale & retail | 2025 |
| JA Technical Services Ltd | Professional & scientific | 2019 |
| Jaab Ltd | Construction | 2025 |
| Jaag Property Ltd | Households | 2024 |
| Jaas Consulting Limited | Professional & scientific | 2025 |
| Jaas Homes Limited | Construction | 2021 |
| JAB & JJB Holdings Limited | Wholesale & retail | 2021 |
| JAB Invest Ltd | Real estate | 2025 |
| Jabbah Bess Limited | Energy | 2022 |
| Jabbi Kassama Care Plus Ltd | Health & social care | 2018 |
| Jabroo Cars Limited | Administrative & support | 2008 |
| Jabulani Homes Limited | Real estate | 1997 |
| JAC Project Management Ltd | Construction | 2018 |
| Jacal Property Management Ltd | Hospitality | 2025 |
| Jacaranda Foods Ltd | Manufacturing | 2019 |
| Jacasia Ltd | Administrative & support | 2018 |
| Jacay Limited | Health & social care | 2021 |
| Jack and Jill Preschool Limited | Education | 2008 |
| Jack and Jones Limited | Public administration | 2019 |
| Jack Black Property Ltd | Real estate | 2019 |
| Jack Branch Ltd | Professional & scientific | 2024 |
| Jack Carpentry & Build Ltd | Construction | 2025 |
| Jack Chamberlain Ltd | Wholesale & retail | 2023 |
| Jack Collings Ltd | Professional & scientific | 2025 |
| Jack Downes Ltd | Professional & scientific | 2024 |
| Jack Gadd Business Consultancy Ltd | Arts & recreation | 2024 |
| Jack Hobday Engineering Surveying Ltd | Construction | 2025 |
| Jack Jacombs Ltd | Extraterritorial | 2023 |
| Jack OV Trades Ltd | Other services | 2025 |
| Jack Pine Trees Ltd | Agriculture & fishing | 2010 |
| Jack Russell Copyright Limited | Administrative & support | 1998 |
| Jack Russell Limited | Wholesale & retail | 1991 |
| Jack the LAD Limited | Information & communication | 2014 |
| Jack Wiles Services Ltd | Arts & recreation | 2014 |
| Jack.Partners LLP | | 2023 |
| Jackal Trading Ltd | Wholesale & retail | 2016 |
| Jackap Ltd | Health & social care | 2026 |
| Jackdaw | | 1993 |
| Jackdaw Homes Ltd | Real estate | 2022 |
| Jackdaw Labs Limited | Manufacturing | 2022 |
| Jackfruit Clothing Ltd | Wholesale & retail | 2021 |
| Jackfruit Design Ltd | Information & communication | 2006 |
| Jackie Brightman Executive Search Limited | Administrative & support | 2021 |
| Jackie Withers Consultancy Ltd | Health & social care | 2011 |
| Jackson & Cole Ltd | Wholesale & retail | 2024 |
| Jackson Property Group Ltd | Real estate | 2020 |
| Jackson Property Invest Limited | Real estate | 2023 |
| Jackson Property Rentals Ltd | Real estate | 2020 |
| Jackson Pullin Properties Ltd | Real estate | 2021 |
| Jackson Trade Co Limited | Real estate | 2025 |
| Jackson's Autos Ltd | Wholesale & retail | 2023 |
| Jacktilda Limited | Real estate | 2022 |
| Jackway Limited | Information & communication | 2012 |
| Jacky Puzey Embroidery Limited | Manufacturing | 2017 |
| Jack’S Garden Services Limited | Other services | 2020 |
| Jacob Goodliffe Residential Sales Ltd | Real estate | 2018 |
| Jacob HAG Property Developments Limited | Construction | 2019 |
| Jacob James Holdings Limited | Wholesale & retail | 2021 |
| Jacob's Automobile Ltd | Wholesale & retail | 2020 |
| Jacob's Barbers (Gloucester Road) Ltd | Other services | 2024 |
| Jacob's Barbers (North Street) Limited | Other services | 2021 |
| Jacob's Barbers (Perry Road) Limited | Other services | 2018 |
| Jacob's Studios Ltd | Wholesale & retail | 2019 |
| Jacob's Wells Road Management Company Limited | Households | 2017 |
| Jacoban Enterprise Limited | Other services | 2017 |