| JD Plumbing & Heating Ltd | Construction | 2024 |
| JE & SA Gardener Limited | Agriculture & fishing | 2025 |
| Jenart Design Limited | Manufacturing | 1998 |
| Jeremy Mosdell Limited | Extraterritorial | 2025 |
| Jetts 247 Limited | Arts & recreation | 2016 |
| Jetts Fitness UK Limited | Financial services | 2015 |
| JFB & SON Limited | Real estate | 2011 |
| JG SERVICES25 Ltd | Health & social care | 2025 |
| JH Digital Consulting Ltd | Professional & scientific | 2020 |
| JIC Renewables Limited | Manufacturing | 2013 |
| JK Auto-Tek LLP | | 2023 |
| JLG Dairy Services Limited | Wholesale & retail | 2024 |
| JM HSE Solutions Ltd | Administrative & support | 2018 |
| JME Commercial Enterprises Ltd | Financial services | 2023 |
| JME Scaffolding Ltd | Construction | 2023 |
| JML Support Services Ltd | Administrative & support | 2026 |
| Jmryan Solutions Ltd | Professional & scientific | 2016 |
| JMT Carpentry Ltd | Construction | 2026 |
| Joanna Clare Medical and Cosmetic PMU Aesthetics Ltd | Other services | 2023 |
| JOE Grimley Developments Ltd | Construction | 2022 |
| John Arbon Ltd | Manufacturing | 2022 |
| John Burns & SON Roofing Limited | | 1986 |
| John Patts Limited | Wholesale & retail | 2003 |
| John Seymour Transport Limited | Transport & logistics | 1978 |
| John Shields Buildings Limited | Manufacturing | 2007 |
| John Shields Holdings Ltd | Real estate | 2025 |
| John Taylor (Fasteners) Limited | Wholesale & retail | 1988 |
| Johns of Instow Limited | Wholesale & retail | 2005 |
| Johnson & SON Property Developments Limited | Real estate | 2017 |
| Jones & Fish Limited | Construction | 2016 |
| JP Ellison Ltd | Information & communication | 2017 |
| JPJ Manufacturing Limited | Wholesale & retail | 2018 |
| JPR Developments (South West) Limited | Real estate | 2026 |
| Jrml Holdings Ltd | Households | 2025 |
| JRN Contracts LLP | | 2026 |
| JRV Construction Ltd | Construction | 2002 |
| Jsce Surveying Ltd | Professional & scientific | 2018 |
| Juniper Made Ltd | Manufacturing | 2025 |
| Just 21 Property Management Ltd | Hospitality | 2022 |
| Just Deals SW Limited | Water & waste | 2024 |
| Just Food Technical Ltd | Professional & scientific | 2018 |
| Just Office Ltd | Wholesale & retail | 2001 |
| JVH Group Ltd | Real estate | 2024 |
| K & E Devon Ltd | Construction | 2021 |
| K & J Electrical Limited | Construction | 2003 |
| K & T Forecourts Limited | Wholesale & retail | 2012 |
| K & T Properties (Devon) Limited | Real estate | 2023 |
| K C Training Services Limited | Health & social care | 2002 |
| K J'S Cleaning Services (South West) Limited | Administrative & support | 2013 |
| K. J. & S. J. Pike Contractors Limited | Construction | 2003 |
| KA & GB Associates Ltd | Construction | 2012 |
| KAD Coastal Properties Ltd | Administrative & support | 2019 |
| Kala Fair 61-66 RTM Company Limited | Professional & scientific | 2011 |
| Kalmaminds Ltd | Other services | 2024 |
| Kaos Entertainments Limited | Real estate | 1983 |
| Kate Kilpatrick Studio Ltd | Arts & recreation | 2025 |
| KBS Aesthetics Ltd | Health & social care | 2024 |
| KCH Developments Ltd | Construction | 2024 |
| KE Chiropody & Podiatry Ltd | Health & social care | 2009 |
| Keefe and SON Engineering Ltd | Wholesale & retail | 2021 |
| Keel Care Limited | Health & social care | 2013 |
| Keenes Catering and Hospitality Ltd | Hospitality | 2018 |
| Keep IT Cool Refrigeration Ltd | Administrative & support | 2005 |
| Keiton Limited | Professional & scientific | 2014 |
| Kellie Simpson Legal Ltd | Administrative & support | 2022 |
| Kenmore Ideas Limited | Other services | 2016 |
| Khadour Transport Ltd | Transport & logistics | 2024 |
| Kingsley Car Sales Limited | Wholesale & retail | 2002 |
| Kingsley Education Limited | Education | 2019 |
| Kingsley Indoor Bowling Company Limited | Arts & recreation | 1992 |
| Kingston Construction (Devon) Limited | Construction | 2002 |
| Kirsty's Home Maintenance Ltd | Construction | 2016 |
| Kirsty's Property Ltd | Real estate | 2019 |
| Kirton Ventures Limited | Real estate | 1995 |
| Kittiwake Charters Limited | Transport & logistics | 2023 |
| Klear Consulting & Business Development Ltd | Public administration | 2023 |
| Klimashell Limited | Wholesale & retail | 2018 |
| KMC Holdings (Devon) Ltd | Financial services | 2023 |
| Koosar Limited | Hospitality | 2018 |
| Koreo Foundation | Education | 2021 |
| Koreo Ltd | Professional & scientific | 2004 |
| Koto Cabins Limited | Manufacturing | 2017 |
| Koto Design Limited | Professional & scientific | 2017 |
| Koto Living Limited | Professional & scientific | 2020 |
| KPM Business Recovery & Insolvency Limited | Professional & scientific | 2019 |
| Krempel Industries Limited | Manufacturing | 2000 |
| KRG Formwork Ltd | Construction | 2021 |
| Krpm Business Solutions Limited | Professional & scientific | 2011 |
| KSB Decor Limited | Construction | 2025 |
| KSI Kingsley School Property Limited | Education | 2019 |
| Kubiak Consulting Limited | Professional & scientific | 2025 |
| Kumuva Digital Limited | Information & communication | 2012 |
| L and H Jewellery Limited | Wholesale & retail | 2024 |
| L D Heywood Limited | Agriculture & fishing | 2002 |
| L R W Construction Ltd | Construction | 2019 |
| L'Objet UK Limited | Wholesale & retail | 2008 |
| LA Furniture International Limited | Wholesale & retail | 2007 |
| Labels of Love Ltd | Manufacturing | 2025 |
| Ladybirds Daycare Ltd | Education | 2005 |
| Lafayette Properties Ltd | Other services | 2016 |