| J.M.Glover Medical Services Limited | Health & social care | 2013 |
| J.R.Griffin & Sons(Bulkington)Limited | Agriculture & fishing | 1946 |
| Jack D Nichols Limited | Administrative & support | 2017 |
| Jack Spratt Devizes Limited | Hospitality | 2010 |
| Jagged Horizons Limited | Administrative & support | 2007 |
| Jalowiecki Oilfield Engineering Services Ltd | Mining & quarrying | 1996 |
| Jalts Properties Ltd | Real estate | 2017 |
| James Kilkenny Architecture & Design Ltd | Professional & scientific | 2015 |
| James's Disco Limited | Arts & recreation | 2021 |
| Jaschlo Ltd | Real estate | 2020 |
| JC Essentials Ltd | Wholesale & retail | 2025 |
| JC Virt Consultancy Limited | Administrative & support | 2014 |
| JCS Air Conditioning Services Limited | Construction | 2004 |
| JE Electrical Contract Services Ltd | Construction | 2023 |
| JEF Consultancy Limited | Professional & scientific | 2021 |
| Jenn Homes Limited | Real estate | 2022 |
| Jewel Management Limited | Wholesale & retail | 1997 |
| JFW Agri Limited | Manufacturing | 2019 |
| JG Devizes Ltd | Hospitality | 2023 |
| JHH Independent Consultants Limited | Professional & scientific | 2007 |
| JJJ Retail Ltd | Wholesale & retail | 2026 |
| Jktg Property Limited | Real estate | 2019 |
| JMG Electrical Services Ltd. | Construction | 2017 |
| JMH Farming & Renewables Ltd | Professional & scientific | 2008 |
| JML Electrical Ltd | Construction | 2025 |
| JO Repairs Limited | Other services | 2026 |
| John 00 Fleming Limited | Arts & recreation | 2000 |
| John Somerville PUB Company Ltd | Hospitality | 2023 |
| Johnsons Arborist Ltd | Agriculture & fishing | 2023 |
| Join UP the Dots-Consultancy Ltd | Professional & scientific | 2021 |
| Joined UP Marketing Solutions Ltd | Professional & scientific | 2021 |
| Jolie Brise Limited | Other services | 1996 |
| Josey Property Ltd | Real estate | 2021 |
| JPT Design Limited | Professional & scientific | 2003 |
| JRS Electrical (Devizes) Ltd | Construction | 2022 |
| JS English Limited | Education | 2023 |
| JSC Construction & Building Services Ltd | Construction | 2023 |
| Julia Dalrymple Ltd | Professional & scientific | 2019 |
| Junah Ltd | Education | 2025 |
| Just Imagine IF CIC | Professional & scientific | 2025 |
| K L & SON Building Maintenance Ltd | Construction | 2022 |
| K L & Sons Building Services Ltd | Construction | 2019 |
| K U Carpentry & Construction Ltd | Construction | 2004 |
| K-Solutions Limited | Information & communication | 1998 |
| K. Kingsbury Limited | Construction | 2002 |
| K2 HR & People Development Limited | Professional & scientific | 2007 |
| K2 Industries Limited | Professional & scientific | 2018 |
| Kate Cobb Travel Ltd | Administrative & support | 2022 |
| Kavanaghs Land and Development Agents Limited | Real estate | 2022 |
| Kennedy Financial Services Limited | Professional & scientific | 1983 |
| Kennet 1ST Limited | Construction | 2016 |
| Kennet and Avon Canal Trust(The) | Arts & recreation | 1962 |
| Kennet Financial Services LLP | | 2015 |
| Kennet Furniture Refurbiz Ltd. | Wholesale & retail | 1996 |
| Kennet Print Ltd | Manufacturing | 2006 |
| Kernow Capital Limited | Professional & scientific | 2019 |
| Kestrel Cpms Limited | Professional & scientific | 2024 |
| Kevin Jenn Carpentry Ltd | Manufacturing | 2015 |
| Kevstoneuk Limited | Professional & scientific | 2023 |
| KH Utran Solution Limited | Information & communication | 2011 |
| Khonsu Limited | Arts & recreation | 2017 |
| Kilda Investments Limited | Administrative & support | 1991 |
| KIN3 Limited | Professional & scientific | 2025 |
| Kinetic Electrical Contractors Ltd | Construction | 2020 |
| Kingsmill Reversion Partnership LLP | | 2007 |
| Kington Events Limited | Other services | 2023 |
| KIT Farm Ltd | Extraterritorial | 2009 |
| Kit's Cashmere and Accessories Limited | Wholesale & retail | 2015 |
| KJ Mackley Leadership Consultancy Ltd | Professional & scientific | 2023 |
| KJM PUB Co Ltd | Hospitality | 2023 |
| KJS Accountants Ltd | Professional & scientific | 2010 |
| Kourser Technologies Ltd | Information & communication | 2022 |
| KSG Bath Limited | Construction | 2011 |
| Kytes Garage Limited | Wholesale & retail | 2016 |
| L & a Gordon Limited | Other services | 2012 |
| LA Vieille Prune Limited | Professional & scientific | 2012 |
| Lady Shaw Limited | Hospitality | 2024 |
| Lakedale Business Systems Limited | Information & communication | 2011 |
| Lansdowne Legal Limited | Professional & scientific | 2011 |
| Lark Accounting Limited | Professional & scientific | 2020 |
| Lataca Limited | Hospitality | 2009 |
| Launchpad Camera Services Ltd | Information & communication | 2020 |
| Lavender Light Ltd | Health & social care | 2024 |
| LB Sales and Consulting Ltd | Wholesale & retail | 2026 |
| Leading Edge Design UK Ltd | Arts & recreation | 2004 |
| Leafield Industrial Estate Limited | Construction | 2008 |
| Ledua Limited | Wholesale & retail | 2025 |
| Lee's Fish & Chips 88 Limited | Hospitality | 2025 |
| Lefebvre Properties Ltd | Real estate | 2023 |
| LEI Registrations Limited | Administrative & support | 2017 |
| Leppard Ashton Advisory Limited | Administrative & support | 2015 |
| Lewis Walker & Co Ltd | Manufacturing | 2014 |
| Lexi's Toy Loft Ltd | Wholesale & retail | 2017 |
| Lfct Ltd | Wholesale & retail | 2023 |
| Light and Sound Devizes Ltd | Wholesale & retail | 2019 |
| Lightstores Ltd | Wholesale & retail | 2023 |
| Lime Polish Deli Limited | Wholesale & retail | 2015 |
| Linden Ruskin Training Limited | Administrative & support | 2003 |
| Lindsey Turnbull Coaching Ltd | Education | 2023 |
| Little ANT Limited | Wholesale & retail | 2020 |