| Jarman Ward Holdings Limited | Financial services | 2020 |
| Jarman Ward Limited | Construction | 2016 |
| Jarmy Recruitment Ltd | Administrative & support | 2025 |
| JB Landscaping & Construction Ltd | Administrative & support | 2023 |
| JC Holdings (Dunkeswell) Ltd | Professional & scientific | 2019 |
| JD7 Ltd | Professional & scientific | 2021 |
| JDB Building & Maintenance Limited | Construction | 2024 |
| JDB Roofing SW Limited | Construction | 2021 |
| JDM Properties South West Ltd | Real estate | 2025 |
| Jefferson Accountancy Ltd | Professional & scientific | 2019 |
| JET Jump Limited | Wholesale & retail | 2015 |
| JET Sports Limited | Wholesale & retail | 2013 |
| JF7 Limited | Professional & scientific | 2022 |
| Jo's Home for Hounds Ltd | Other services | 2019 |
| Johnson Rand Ltd | Professional & scientific | 2018 |
| Joyce Group Holdings Limited | Financial services | 2025 |
| JP Racing (Devon) Ltd | Wholesale & retail | 2025 |
| JPG Build Limited | Construction | 2021 |
| JR Layzell & Sons Limited | Construction | 2002 |
| JRI Consultancy Limited | Professional & scientific | 2018 |
| JSL ACQ1. Limited | Arts & recreation | 2022 |
| Jump HI Limited | Real estate | 2015 |
| Juniper Clinical Therapies Ltd | Health & social care | 2024 |
| Jurassic Heating Limited | Manufacturing | 2021 |
| Just Cards (Honiton) Limited | Wholesale & retail | 2007 |
| Just Milk Ltd. | Hospitality | 2022 |
| JVB Accounting Services Limited | Professional & scientific | 2024 |
| K Darnell Holding Co Ltd | Financial services | 2026 |
| K J Broom Ltd | Construction | 2017 |
| K&G Home Improvements Ltd | Other services | 2022 |
| K-Tech Electrical (SW) Limited | Construction | 2017 |
| K. J. Parris & Partners Ltd | Agriculture & fishing | 2022 |
| K9 Munchtime Ltd | Wholesale & retail | 2014 |
| Karats Limited | Wholesale & retail | 2002 |
| Karibu Engineering Limited | Manufacturing | 2000 |
| KAY Tregenna Architects Limited | Professional & scientific | 2019 |
| KDB Renovations Ltd | Construction | 2024 |
| KDJ Properties Limited | Real estate | 2021 |
| Keith Luxton & Co. Limited | Professional & scientific | 2002 |
| Kennard Consulting Ltd | Information & communication | 2020 |
| Kercombe Consulting Ltd | Professional & scientific | 2022 |
| Kerpac Limited | Wholesale & retail | 2019 |
| Kevin Hall Plumbing & Heating Limited | Manufacturing | 2015 |
| Kevser Consultancy Ltd | Construction | 2020 |
| Keyhole Locksmiths Ltd | Wholesale & retail | 2023 |
| Keysoft Information Systems Limited | Information & communication | 1990 |
| Keystage History Online Ltd | Education | 2008 |
| KIP Planer Ltd | Construction | 2010 |
| KJG Accountancy Services Ltd | Professional & scientific | 2009 |
| KLM Residential Ltd | Real estate | 2016 |
| Kmels Cleaning Services Ltd | Administrative & support | 2026 |
| KMR Properties (Oxford) Ltd | Real estate | 2015 |
| Knight Autocare Ltd | Professional & scientific | 2026 |
| Knight Plumbing & Heating South West Limited | Construction | 2019 |
| Knightsbridge KNG Group Ltd | Professional & scientific | 2023 |
| Ko-Be Homes Ltd | Real estate | 2024 |
| Kool Katz Ltd | Wholesale & retail | 2026 |
| KPR Care Services Limited | Health & social care | 2011 |
| KTH Properties SW Ltd | Real estate | 2021 |
| Kuba Construction Ltd | Construction | 2023 |
| KW & JM Hulbert Limited | Agriculture & fishing | 2005 |
| L a Baden Limited | Education | 2013 |
| L&M Renewables South West Limited | Construction | 2023 |
| Lagging Solutions South West Limited | Construction | 2019 |
| Lamplight Holdings Limited | Real estate | 2015 |
| Lamplight Properties (Oxford) Limited | Real estate | 1993 |
| Lasercutz Ltd | Manufacturing | 2013 |
| Lastglade Builders Limited | Wholesale & retail | 1984 |
| Laughingphoenix Limited | Professional & scientific | 2010 |
| LDT Interiors Limited | Manufacturing | 2023 |
| Leadership South West Limited | Extraterritorial | 2025 |
| Ledger Scaffolding Holding Limited | Financial services | 2025 |
| Leemolabs Limited | Professional & scientific | 2023 |
| Leiftech Limited | Other services | 2010 |
| Lemon Tree Digital Marketing Ltd | Professional & scientific | 2023 |
| Lewdan Marketplace Ltd | Wholesale & retail | 2022 |
| Lexys Hair Limited | Other services | 2017 |
| Leyera Ltd | Wholesale & retail | 2025 |
| Leyhill Holdings Ltd | Financial services | 2025 |
| Lezanda Capital Limited | Professional & scientific | 2010 |
| Life Education Wessex | Other services | 1998 |
| Lifeline Medical Solutions Limited | Health & social care | 2025 |
| Lilac Haven Management Company Limited | Households | 2016 |
| Line Electrics Limited | Construction | 2020 |
| Linwar Motors Limited | Wholesale & retail | 1991 |
| Lion Brewery Co. Limited | Manufacturing | 2017 |
| Little Bubble Launderette Limited | Other services | 2022 |
| Littletown Residents Association Limited | Households | 1986 |
| LKW Brickworks Limited | Construction | 2016 |
| LO Monaco Ltd | Health & social care | 2019 |
| Local Home Surveys Ltd | Professional & scientific | 2024 |
| Longmeadow Homes Limited | Hospitality | 1982 |
| Lorimer Consulting Limited | Professional & scientific | 2014 |
| Lottydom Limited | Other services | 2019 |
| Love Shack VTG Ltd | Wholesale & retail | 2019 |
| Love the Day Ltd | Agriculture & fishing | 2021 |
| Lovely Bridal Limited | Wholesale & retail | 2016 |
| Lovett Education Consultancy Limited | Education | 2019 |
| LPC Supplies Ltd | Wholesale & retail | 2016 |
| LRD Holdings Limited | Financial services | 2024 |