| Jastat Limited | Administrative & support | 2025 |
| JAT Barrs Limited | Hospitality | 2021 |
| JAW Roofing Ltd | Construction | 2025 |
| Jaxan Property Ltd | Real estate | 2022 |
| JB Carpentry & Construction SW Ltd | Manufacturing | 2025 |
| JB Consultancy (SW) Limited | Administrative & support | 2025 |
| JB Trees Ltd | Administrative & support | 2025 |
| JB Utilities & Groundworks Ltd | Construction | 2025 |
| JBG Airsoft Ltd | Information & communication | 2023 |
| JBM Advisory Ltd | Professional & scientific | 2025 |
| Jbnp Warranty Services Limited | Construction | 2009 |
| JBS Combines Ltd | Hospitality | 2020 |
| Jbux Services Ltd | Information & communication | 2024 |
| JBV Aircraft Services Ltd | Manufacturing | 2022 |
| JC Bodyworks Ltd | Wholesale & retail | 2014 |
| JC Motorcycles Limited | Wholesale & retail | 2007 |
| JC Self Storage Limited | Real estate | 2011 |
| JC Sound Recording Limited | Information & communication | 2022 |
| JCB Financial & Commercial Limited | Professional & scientific | 2012 |
| JCL (South West) Limited | Real estate | 2021 |
| JCM Plumbing & Heating SW Ltd | Construction | 2026 |
| Jcom Safeguarding Ltd | Health & social care | 2014 |
| JCP EYE Surgery Limited | Health & social care | 2016 |
| JD Dryline Ltd | Construction | 2019 |
| JD Industries Ltd | Construction | 2018 |
| JDH ERP & Project Management Ltd. | Professional & scientific | 2014 |
| JDW Homes & Developments Ltd | Real estate | 2025 |
| Jedwim Limited | Professional & scientific | 2020 |
| Jefferis Plymouth Limited | Construction | 2016 |
| Jefferson Investments Limited | Real estate | 2019 |
| Jeffery & Sartin Ltd | Health & social care | 2023 |
| Jeffery and Pengelly Limited | Construction | 2017 |
| JEH Professional Services Limited | Health & social care | 2023 |
| Jeml Dynamics Ltd | Information & communication | 2026 |
| Jemm Collective Agency Ltd | Professional & scientific | 2026 |
| Jemmy Ltd | Professional & scientific | 2007 |
| Jenner Homes Limited | Construction | 1996 |
| Jenner Medical Ltd | Professional & scientific | 2010 |
| Jennie Wren JW Ltd | Wholesale & retail | 2023 |
| Jennifer Ladd Ltd | Real estate | 2026 |
| Jepsonbreyley Ltd | Professional & scientific | 2021 |
| Jeramie Chan Limited | Health & social care | 2022 |
| Jerzyroll&Go Ltd | Transport & logistics | 2024 |
| JET SET Go Torquay Ltd | Arts & recreation | 2026 |
| JET SKI U.K Ltd | Manufacturing | 2021 |
| Jethtrans Ltd | Transport & logistics | 2025 |
| Jetset Limited | Professional & scientific | 2003 |
| Jett M Ltd | Hospitality | 2025 |
| Jewell Lettings Limited | Real estate | 2022 |
| JFH Enterprises Ltd | Financial services | 2024 |
| JFK Exeter Limited | Hospitality | 2012 |
| JFS Medical Limited | Health & social care | 2014 |
| JGH Construction Ltd | Manufacturing | 2019 |
| JH Buckerell Ltd | Hospitality | 2020 |
| JH G&D Holdings Limited | Financial services | 2026 |
| JH Investment Properties Ltd | Households | 2025 |
| JH Korean Taste Ltd | Hospitality | 2024 |
| JHP (Exeter) Limited | Professional & scientific | 2013 |
| JHP Recruitment Group Ltd | Financial services | 2024 |
| JHP Recruitment Ltd | Administrative & support | 2015 |
| JHS Health and Safety Consultants Ltd | Administrative & support | 2019 |
| JI Chicken Exeter Limited | Hospitality | 2025 |
| Jibari Ltd | Real estate | 2018 |
| Jillant Properties Limited | Real estate | 2012 |
| JIM Enterprises Limited | Real estate | 1998 |
| Jinli Exeter Limited | Hospitality | 2023 |
| Jireh (SW) Ltd | Financial services | 2025 |
| Jittan Ltd | Information & communication | 2026 |
| Jiwa Holdings Ltd | Information & communication | 2017 |
| JJ Mobile Valeting Ltd | Administrative & support | 2023 |
| JK & AK Property Limited | Real estate | 2018 |
| JK and AK Consultancy Limited | Professional & scientific | 2018 |
| JK Developments Limited | Construction | 2011 |
| JK Floorheating Ltd | Construction | 2016 |
| JK Technical Advisors Limited | Professional & scientific | 2011 |
| JKA Healthcare Limited | Health & social care | 2019 |
| JKG Developments (SW) Limited | Real estate | 2024 |
| JKI Corrosion Control Ltd | Construction | 2024 |
| JKL Homes Ltd | Hospitality | 2016 |
| Jkmf Catering Limited | Hospitality | 2013 |
| JL Content Ltd | Wholesale & retail | 2026 |
| JL Manton & DM Manton Food Services Ltd | Hospitality | 2021 |
| JL Prime Property Limited | Real estate | 2020 |
| JL Props Limited | Real estate | 1997 |
| JL Stevens Ltd | Information & communication | 2022 |
| Jlbuilds Southwest Ltd | Construction | 2024 |
| JLG MOZ D/C 1 Limited | Information & communication | 2026 |
| Jlhh Ltd | Professional & scientific | 2018 |
| JLJ Roofing & Cladding Ltd | Construction | 2022 |
| JLM Property Ventures Ltd | Real estate | 2024 |
| JLW Carpentry & Construction Ltd | Manufacturing | 2025 |
| JLX Coaching Limited | Education | 2020 |
| JM Enviro Limited | Professional & scientific | 2017 |
| JMB Online Ltd | Wholesale & retail | 2020 |
| JMC Aviation Limited | Administrative & support | 2008 |
| JMC Recruitment Solutions Limited | Extraterritorial | 2020 |
| Jmc-Group Ltd | Financial services | 2013 |
| JMD Facilities Management Co Ltd | Construction | 2024 |
| JME Xxii Ltd | Real estate | 2021 |
| JMJ Carpentry Ltd | Construction | 2024 |