| Jdskillschool Ltd | Education | 2025 |
| Jdub Limited | Financial services | 2024 |
| JDW Carpenters Ltd | Construction | 2015 |
| JED Mason Plumbing and Heating Limited | Construction | 2015 |
| Jellyfish Limited | Professional & scientific | 1994 |
| Jenkinson Potts Construction Limited | Construction | 2014 |
| JEP Collective Ltd | Wholesale & retail | 2026 |
| Jerry Kent Ltd | Professional & scientific | 2011 |
| JEV DEV (Southwest) Ltd | Construction | 2025 |
| JEV DEV Builders Ltd | Construction | 2025 |
| JEV DEV Renewables Ltd | Construction | 2025 |
| Jevdev Ltd | Construction | 2025 |
| Jewelico Ltd | Wholesale & retail | 2018 |
| JJ & H Thorne LLP | | 2026 |
| JJJ Foods Ltd | Hospitality | 2020 |
| Jlrm Accounting Ltd | Professional & scientific | 2023 |
| Jody Medland Limited | Health & social care | 2026 |
| Joelna Limited | Education | 2021 |
| John Blackmore Farming Ltd | Agriculture & fishing | 2012 |
| John Dony Ltd | Professional & scientific | 2024 |
| John Ferguson Photography Limited | Information & communication | 2010 |
| John Fowler Holdings Limited | Hospitality | 2016 |
| John Fowler Holidays Limited | Hospitality | 1965 |
| John Hockin (Braunton) Limited | Construction | 1954 |
| John Manton Gunmaker Limited | Manufacturing | 2018 |
| John Smale & Co Ltd | Real estate | 2021 |
| Johnson Recruitment Limited | Administrative & support | 2008 |
| Joltr Ltd | Manufacturing | 2026 |
| Joluxan Holdings Limited | Professional & scientific | 2012 |
| JON Beer Auto Services Limited | Wholesale & retail | 2013 |
| Jonathan Rhind. Architects Ltd. | Professional & scientific | 2007 |
| Josh Staddon Scaffolding Ltd | Construction | 2023 |
| Journo Resources Limited | Information & communication | 2017 |
| JP Safety Consultancy Ltd | Professional & scientific | 2024 |
| JP Windows and Doors Ltd | Construction | 2021 |
| Jphysique Body Composition Consultancy Ltd | Other services | 2016 |
| JPK Building Contractors Limited | Construction | 2013 |
| JPS Ideal Ltd | Construction | 2025 |
| JR Construction and Scaffolding Ltd | Construction | 2023 |
| JRA Business Development LLP | | 2014 |
| JS Kurd Fade Ltd | Other services | 2024 |
| JS Residual Ltd | Manufacturing | 1999 |
| JSS (North Devon) Limited | Real estate | 2014 |
| JT Property (Devon) Ltd | Real estate | 2025 |
| Jtsk Davies Locum Ltd | Wholesale & retail | 2022 |
| Jubilee Court Management Company (Lynton) Limited | Households | 2008 |
| Judge & Mitchell Associates LLP | | 2011 |
| Junglaroo Limited | Arts & recreation | 2006 |
| Jurvicka Limited | Health & social care | 2014 |
| Justin &Jude Company Ltd. | Health & social care | 2016 |
| JWC Trading Limited | Professional & scientific | 2024 |
| Jwev Ltd | Wholesale & retail | 2025 |
| JWM (Devon) Limited | Financial services | 2017 |
| K J Refrigeration Ltd | Energy | 2003 |
| K S Fencing and Groundworks Limited | Construction | 2025 |
| K&K Legal Consulting Ltd | Professional & scientific | 2021 |
| K.J.L Holdings Limited | Real estate | 2016 |
| Kaboodle Laundry Services Ltd | Other services | 2020 |
| Kairos Global Construction Ltd | Construction | 2023 |
| Kala Management 2002 Limited | Households | 2002 |
| Kameleon Group Limited | Information & communication | 2014 |
| Karma Optical Ltd | Health & social care | 2025 |
| KAS Crane Hire Limited | Administrative & support | 2003 |
| Kaydenz Limited | Wholesale & retail | 2021 |
| KDN Day Nurseries Limited | Financial services | 2025 |
| Keele Torrington Lane Management Company Limited | Real estate | 2019 |
| Keeping YOU Warm National Limited | Wholesale & retail | 2022 |
| Keith Parkin Farrier Limited | Other services | 2003 |
| Keiway Electrical Engineering Limited | Administrative & support | 2005 |
| Kendall Wallace Limited | Professional & scientific | 2001 |
| Kent's Salon Braunton Ltd | Other services | 2024 |
| Kentisbury Properties Limited | Hospitality | 2024 |
| Kenwyn Limited | Wholesale & retail | 2023 |
| Kerb Appealz Limited | Real estate | 2013 |
| Kerslake Farming Limited | Agriculture & fishing | 2019 |
| Kethro Ltd | Wholesale & retail | 2014 |
| Kevin Wheatley Limited | Professional & scientific | 2021 |
| Kfco Marketing LLP | | 2014 |
| Kfried Limited | Agriculture & fishing | 2021 |
| Kiarani Ltd | Information & communication | 2012 |
| Kiddywinks Childcare Limited | Education | 2003 |
| Kiff Ward Ltd | Construction | 2025 |
| Kiff-Fencing Ltd | Manufacturing | 2025 |
| Kili Consulting Limited | Professional & scientific | 2014 |
| Kiming RTM Company Limited | Households | 2007 |
| Kind and Wild Ltd | Extraterritorial | 2022 |
| Kingdons Court Apartment Management Company Limited | Real estate | 2012 |
| Kingdons Court Estate Management Company Limited | Real estate | 2012 |
| Kingfisher and Key Financial Solutions Limited | Financial services | 2018 |
| Kings Carpets (Devon) Limited | Wholesale & retail | 1974 |
| Kings Pawfection Limited | Other services | 2017 |
| Kingston Apartments (Yorkshire) Limited | Real estate | 2013 |
| Kingston Renovations Limited | Households | 2018 |
| Kingston Ventures Limited | Hospitality | 2010 |
| King’S Paramedical Services Ltd | Education | 2026 |
| Kinie Ltd | Wholesale & retail | 2025 |
| Kittenpaws Ltd | Wholesale & retail | 2024 |
| Knightacott Management Services Limited | Professional & scientific | 2005 |
| Knowle Developments Limited | Construction | 2008 |
| Knowlwater Caen Limited | Professional & scientific | 2013 |