| JSS Healthcare Ltd | Administrative & support | 2015 |
| JSS Homecare Ltd | Health & social care | 2020 |
| JSS Professional Services (Dorchester) Limited | Professional & scientific | 2015 |
| JTM Construction Services Ltd | Construction | 2017 |
| Juberi Group (Consulting) Limited | Information & communication | 2024 |
| Juberi Group Limited | Information & communication | 2021 |
| Junglezone Ltd | Professional & scientific | 2007 |
| Just Trade Websites Limited | Professional & scientific | 2010 |
| Justelle Marketing & Media Ltd | Professional & scientific | 2015 |
| Justjen CIC | Health & social care | 2025 |
| Jvskippys Limited | Hospitality | 2025 |
| JW Electrical Solutions (Yeovil) Limited | Manufacturing | 2016 |
| K & J Services Ltd | Construction | 2026 |
| K & S Dorset Catering Limited | Hospitality | 2014 |
| K D Construction Safety Services Limited | Education | 1997 |
| K&Gs 2 Ltd | Administrative & support | 2010 |
| K&S Motors Partnership Ltd | Wholesale & retail | 2026 |
| K. & M. COX Limited | Extraterritorial | 2012 |
| Kallam CK Limited | Transport & logistics | 2025 |
| Kalpati Group Ltd | Information & communication | 2024 |
| Katbea Ltd | Professional & scientific | 2023 |
| Kate Arbuthnott Interior Design Limited | Other services | 2008 |
| Katie Cooper Coaching Limited | Professional & scientific | 2022 |
| Kauri Apato Ltd | Construction | 2017 |
| Kazopp Limited | Mining & quarrying | 2014 |
| KB Family Products Limited | Wholesale & retail | 2023 |
| KCB Consultancy Limited | Professional & scientific | 2011 |
| Kelvin Solutions Limited | Transport & logistics | 2019 |
| Kent DEV LLP | | 2012 |
| Key Change Education Limited | Administrative & support | 2017 |
| Key Simulation Limited | Professional & scientific | 2004 |
| KG Software Services Ltd | Information & communication | 2023 |
| King Electrical Contracting Ltd | Construction | 2013 |
| Kingsdown Holiday Homes Limited | Hospitality | 2020 |
| Kins Barber Salon Ltd | Other services | 2025 |
| Kirkland Investments Ltd | Wholesale & retail | 2024 |
| Kirkland Sales Limited | Wholesale & retail | 2023 |
| Kirklands Sales Ltd | Wholesale & retail | 2024 |
| Kirkpatrick Property Limited | Households | 2025 |
| Kitchen @ SBC Limited | Hospitality | 2025 |
| Kitchen Kind Limited | Construction | 2011 |
| KK Sales Center Ltd | Wholesale & retail | 2023 |
| Klb-Evolve Ltd | Professional & scientific | 2012 |
| Knewmethod Ltd | Hospitality | 2018 |
| Knightley Inns Management Ltd | Hospitality | 2026 |
| Knights Deliveries Limited | Transport & logistics | 2012 |
| Knotts Farm Barns Management Company Limited | Households | 2023 |
| Knowle Farm Events Ltd | Hospitality | 2023 |
| Kobol Capital Investments Ltd | Information & communication | 2026 |
| Koller Engineering (Holdings) Limited | Manufacturing | 2017 |
| Koller Engineering Limited | Manufacturing | 1981 |
| Kontrolit.Net Limited | Information & communication | 1998 |
| Kore Associates Limited | Health & social care | 2013 |
| Kored Associates Ltd | Health & social care | 2025 |
| Kores Associates Ltd | Health & social care | 2025 |
| Krishna Imaging Limited | Professional & scientific | 2021 |
| Krose Children Ware Limited | Wholesale & retail | 2025 |
| Kuan and LAM Properties Ltd | Real estate | 2025 |
| Kutes Agency Limited | Professional & scientific | 2013 |
| KY Food Ltd | Hospitality | 2023 |
| KYC Support Services Limited | Information & communication | 2012 |
| L C Pension Properties Limited | Extraterritorial | 2018 |
| L Chard Hand Carwash Limited | Other services | 2016 |
| L Couriers Ltd | Transport & logistics | 2022 |
| L M Kendall Limited | Agriculture & fishing | 2020 |
| L Property & Lettings Ltd | Real estate | 2024 |
| L&J Logistics Ltd | Transport & logistics | 2025 |
| L. Dewey & Co. Limited | Agriculture & fishing | 1983 |
| LA & RW Piper Limited | Wholesale & retail | 2012 |
| Laavya Limited | Other services | 2024 |
| LABELLE263 Ltd | Health & social care | 2017 |
| Labrador Rescue (Trading) Limited | Professional & scientific | 2001 |
| Labtek Services Limited | Manufacturing | 2004 |
| Labyrinth Computers Limited | Information & communication | 2001 |
| Laidort Limited | Hospitality | 1982 |
| Lakeland Dental Ltd | Health & social care | 2023 |
| Lakeland Investments Holding Limited | Financial services | 2024 |
| Lakeland Oral Healthcare Ltd | Health & social care | 2019 |
| Lakeside Caravan & Camping Park Ltd | Hospitality | 2024 |
| Lanacre Estate Limited | Agriculture & fishing | 2025 |
| Landmark Software Ltd | Information & communication | 2021 |
| Lanham & Francis Limited | Professional & scientific | 1986 |
| Laser Vehicle Services Limited | Transport & logistics | 2006 |
| Latched Consultancy Limited | Professional & scientific | 2019 |
| Latesys Limited | Professional & scientific | 2009 |
| Launston Group Limited | Construction | 2020 |
| Launston Limited | Construction | 2022 |
| Lavant Automobile Restoration Limited | Wholesale & retail | 2023 |
| Lawrence Scaffolding Limited | Administrative & support | 1992 |
| Lawton Forestry Limited | Agriculture & fishing | 2003 |
| LBR Ventures Limited | Real estate | 2025 |
| LC Amazing Care Limited | Health & social care | 2016 |
| Leading Rehab Limited | Health & social care | 2006 |
| Leal Solutions Ltd | Professional & scientific | 2021 |
| Lean Aerospace Consulting Ltd | Other services | 2014 |
| Lean Farming UK Ltd | Professional & scientific | 2024 |
| LED Accountancy Services Limited | Professional & scientific | 2017 |
| Leftbank Communications Limited | Professional & scientific | 2017 |
| Legal Library Services Limited | Administrative & support | 1984 |
| Leigh House Trust Limited | Real estate | 1996 |