| JAB Holdings (Wells) Ltd | Financial services | 2024 |
| JAB Resources Limited | Construction | 2002 |
| Jack Heginbotham Golf Limited | Wholesale & retail | 2014 |
| Jackson Associates (SW) Limited | Information & communication | 2023 |
| Jackson O'Connor Architecture Ltd | Professional & scientific | 2018 |
| Jakke Yacht & Villa Stylists Ltd | Wholesale & retail | 2019 |
| Jakoti Ltd | Wholesale & retail | 2012 |
| Jalb Interiors Ltd | Construction | 2023 |
| James Mercer Limited | Wholesale & retail | 2001 |
| James Stainer Ltd | Professional & scientific | 2026 |
| Janbar SUB Limited | Real estate | 2014 |
| Jason Steele Management Ltd | Construction | 2018 |
| Jaypeg Ltd | Information & communication | 2012 |
| JB and PB Limited | Education | 1996 |
| JC Fencing & Groundworks Ltd | Construction | 2020 |
| JC Gentlemen's Ltd | Other services | 2021 |
| JCH Group Limited | Financial services | 2025 |
| JED Chidgey Limited | Professional & scientific | 2021 |
| Jefferies, Building & Roofing Ltd | Construction | 2012 |
| Jefory Limited | Wholesale & retail | 2011 |
| Jenbee Limited | Construction | 2011 |
| Jesk Developments Ltd | Households | 2019 |
| Jetco Drainage Services Ltd | Water & waste | 2024 |
| Jetona Limited | Professional & scientific | 2013 |
| JF Electrical Services Limited | Manufacturing | 2003 |
| JHG Electrical Ltd | Construction | 2023 |
| Jigsaw Marketing and Media Limited | Wholesale & retail | 2001 |
| Jive Feel Alive Ltd | Manufacturing | 2024 |
| JJ & Co Holdings Ltd | Real estate | 2016 |
| JJS Enterprises Limited | Information & communication | 2019 |
| Jkmt Limited | Hospitality | 2015 |
| JML Aviation Limited | Transport & logistics | 2025 |
| Johnstone Court Limited | Other services | 2004 |
| Joias Ltd | Wholesale & retail | 2002 |
| Joias Trading Limited | Wholesale & retail | 2009 |
| Jolliffe Films Limited | Information & communication | 2015 |
| Jomiko Limited | Information & communication | 2014 |
| JON Rossi Properties Limited | Real estate | 2004 |
| Jones Sport Campers Ltd | Manufacturing | 2021 |
| Josh Tully Management Ltd | Hospitality | 2020 |
| Jost Explore Ltd | Information & communication | 2021 |
| Jotham Design and Living Limited | Construction | 2004 |
| Joy Day Limited | Hospitality | 2026 |
| Joynd Co Ltd | Manufacturing | 2023 |
| JP & Co Estate Planning Ltd | Professional & scientific | 2026 |
| JP & Co Fiduciary Ltd. | Professional & scientific | 2024 |
| JP Construction (Wells) Ltd | Construction | 2022 |
| JRL Parts Limited | Wholesale & retail | 2015 |
| JRW Consultancy Group Ltd | Administrative & support | 2026 |
| Judges Lodgings Management Company Limited | Households | 1978 |
| Julie COX Consultancy Ltd | Education | 2016 |
| Just a Little Build Ltd | Construction | 2018 |
| Just BEE Ltd | Health & social care | 2019 |
| Just Plants Bristol Limited | Administrative & support | 2009 |
| Jvdc Electrical Ltd | Construction | 2015 |
| JVG Limited | Real estate | 2025 |
| JW Perkins Consulting Ltd | Administrative & support | 2020 |
| K J Carpets Limited | Wholesale & retail | 2008 |
| K M Jones Electrical Limited | Construction | 2015 |
| K.A.T. 1978 Ltd | Other services | 2017 |
| Kale Properties Ltd | Real estate | 2018 |
| Karmanutra Ltd | Manufacturing | 2019 |
| Kate and SAM Lighting Designers Limited | Construction | 2015 |
| Kaye Design Studios Limited | Professional & scientific | 2021 |
| Kaymamar Limited | Hospitality | 2025 |
| Keboko Limited | Professional & scientific | 2023 |
| Keep Diving Limited | Arts & recreation | 2023 |
| Kendrick Holdings Limited | Real estate | 1963 |
| Kestrel Motor Services Ltd | Wholesale & retail | 2026 |
| Keswick Management Ltd | Professional & scientific | 2002 |
| Keward Mill House Limited | Real estate | 2018 |
| Keyward Properties Ltd | Real estate | 2020 |
| KFS Management Ltd | Transport & logistics | 2022 |
| KFS Properties Ltd | Real estate | 2018 |
| KIM Harvey Interiors Limited | Professional & scientific | 2017 |
| Kingdom Training Limited | Arts & recreation | 2016 |
| Kingfisher Wealth Management Ltd | Financial services | 2019 |
| Kingstech Construction Limited | Construction | 2005 |
| Kinophe Transactional Services Ltd | Professional & scientific | 2019 |
| Kirsty Lake Ltd | Professional & scientific | 2023 |
| Kleingeld Young and Partners Limited | Administrative & support | 2009 |
| Knife Fork Bottle and Cork Ltd | Hospitality | 2010 |
| KNW Group Limited | Wholesale & retail | 2003 |
| Kontroll Technik Ltd | Professional & scientific | 2021 |
| Kowalah Limited | Information & communication | 2016 |
| KS Dhami Consulting Ltd | Administrative & support | 2020 |
| KW Media Services Ltd | Information & communication | 2021 |
| Kythira I T Limited | Information & communication | 2005 |
| L & H Bristol Limited | Real estate | 2003 |
| L F C (Somerset) Ltd | Transport & logistics | 1984 |
| Labyrinth Chauffeurs Ltd | Transport & logistics | 2024 |
| LAH DE DAH Productions Limited | Information & communication | 2025 |
| Land & Sea Surveys Ltd | Professional & scientific | 2021 |
| Landkey Financial Advisory Limited | Financial services | 2026 |
| Landmead Property Ltd | Real estate | 2017 |
| Landscape Editions Limited | Information & communication | 2020 |
| Lark Properties (SW) Limited | Construction | 2025 |
| Lattiford House and Court (Management) Limited | Households | 2005 |
| Lattiford Management Company Limited | Households | 2003 |
| Launcherley Tourism Limited | Information & communication | 2016 |