| Jakes Lulworth Limited | Hospitality | 2017 |
| James Wood Construction Ltd | Construction | 2002 |
| Jane's Places Ltd | Hospitality | 2017 |
| Jardin Fleuri Ltd | Wholesale & retail | 2024 |
| Jaycom Services Limited | Professional & scientific | 1998 |
| JB Plumbing & Heating Ltd | Construction | 2013 |
| JCF Productions Limited | Arts & recreation | 2026 |
| Jent Property Dorset Ltd | Real estate | 2024 |
| JET Cleaning and Property Services Ltd | Administrative & support | 2023 |
| Jfdrummond Ltd | Arts & recreation | 2016 |
| JKT Industries LLP | | 2018 |
| JMW Steel Construction Limited | Construction | 2017 |
| John Baggs (Farmers) Limited | Agriculture & fishing | 1975 |
| Johnsandy Ltd | Wholesale & retail | 2007 |
| Jordan Calypso Limited | Professional & scientific | 1993 |
| Jordan Williams Law Limited | Professional & scientific | 2013 |
| Joshua Bushell Trading AS Dust Buster Cleaning Services Ltd | Administrative & support | 2026 |
| JS Marine Limited | Professional & scientific | 2017 |
| JSM Utility Solutions Ltd | Energy | 2026 |
| JT & SON Construction Ltd | Construction | 2015 |
| Jude Morris Racing Foundation CIC | Arts & recreation | 2022 |
| Jurassic Watersports Outdoor Adventure Specialists Ltd | Arts & recreation | 2023 |
| Juvo Enterprises Limited | Education | 2020 |
| K Walkin Shoe Store Ltd | Wholesale & retail | 2024 |
| K.Taylor Engineering Ltd | Professional & scientific | 2022 |
| Kecr Marine Electrical Ltd | Administrative & support | 2022 |
| Keep IT Fluffy Limited | Professional & scientific | 2022 |
| Kennington Square Limited | Households | 1999 |
| Kerley & GUY Limited | Hospitality | 1965 |
| Keystone Species Limited | Manufacturing | 2022 |
| Kingston Country Courtyard Limited | Agriculture & fishing | 1976 |
| Kingswood Farm (Corfe Castle) Limited | Agriculture & fishing | 2014 |
| Knaveswell Sporting Ltd | Arts & recreation | 2025 |
| Krish Smile PVT Ltd | Health & social care | 2012 |
| KRP Stores Limited | Wholesale & retail | 2019 |
| Kuber Sandford Ltd | Wholesale & retail | 2026 |
| Kwik Store Limited | Extraterritorial | 2016 |
| Laetus Property Ltd | Real estate | 2013 |
| Laid-Back Languages Ltd | Education | 2023 |
| Lampton Close Management Company Limited | Households | 2015 |
| Land of Spice (Wareham) Limited | Hospitality | 2019 |
| Lantern Strategy Ltd | Professional & scientific | 2026 |
| Laurens Catering Ltd | Hospitality | 2026 |
| Lazy Lake Ltd | Agriculture & fishing | 2024 |
| Lees News (Wimborne) Limited | Wholesale & retail | 2007 |
| Leigh Gilbert Film & T.V. SET Construction Ltd | Construction | 1999 |
| Leon Consulting (Dorset) Ltd | Professional & scientific | 2013 |
| LET ME Lead Ltd | Other services | 2019 |
| Like a Shot West Limited | Information & communication | 2011 |
| Lilicas Desserts Ltd | Hospitality | 2025 |
| Lion Network Services Limited | Arts & recreation | 2018 |
| Little Tokens Ltd | Hospitality | 2022 |
| Little Walton Randalls Ltd | Construction | 2019 |
| Livingspace Construction Ltd | Construction | 2024 |
| Lizban Limited | Wholesale & retail | 2010 |
| LMG Design Consultancy Ltd | Construction | 2010 |
| Lobustra Ltd | Administrative & support | 2025 |
| Longhill Brighton Ltd | Construction | 2019 |
| Longthorns Farm Limited | Agriculture & fishing | 2010 |
| Lotek UK Ltd | Manufacturing | 1994 |
| Louis Thompson Building Limited | Construction | 2025 |
| Love IT Local Ltd | Information & communication | 2019 |
| Lul-Med Services Ltd | Education | 2010 |
| Lulworth Activities Ltd | Wholesale & retail | 2020 |
| Lulworth Estate Trustees Limited | Extraterritorial | 2018 |
| M J White Limited | Wholesale & retail | 2000 |
| M&J Furnishing Limited | Wholesale & retail | 2012 |
| M&S Zorba Ltd | Construction | 2020 |
| Maggiecontracting Limited | Professional & scientific | 2013 |
| Magnetic Fields Limited | Manufacturing | 1991 |
| Make Profit Europe Limited | Hospitality | 2024 |
| Margaret Green Animal Rescue (Trading) Ltd | Wholesale & retail | 2016 |
| Martin James Holdings Limited | Financial services | 2026 |
| Maverick Publishing Specialists Limited | Professional & scientific | 2011 |
| Mavrix Designs Ltd | Other services | 2019 |
| MCM Health Solutions Ltd | Wholesale & retail | 2026 |
| Meadowstone Property Services Ltd | Administrative & support | 2025 |
| Medico Legal Pagination Ltd | Administrative & support | 2022 |
| Merchant Collection Ltd | Wholesale & retail | 2026 |
| Metal Clay Ltd | Wholesale & retail | 2004 |
| MH Garden Services (Dorset) Ltd | Administrative & support | 2016 |
| Mill Lane Garage (Wareham) Limited | Wholesale & retail | 2013 |
| Mill Lane Management Company Wareham Ltd | Households | 2017 |
| Mission Insight Partners Ltd | Professional & scientific | 2026 |
| MKG Bournemouth Ltd | Education | 2019 |
| Modern Economical Housing Ltd | Construction | 2021 |
| MOO Chuu Ltd | Wholesale & retail | 2022 |
| Moonfleet Developments Limited | Construction | 2024 |
| Morgan Carey Architects Limited | Professional & scientific | 1988 |
| Mortons Manor Limited | Hospitality | 2000 |
| MUD Shark Ltd | Information & communication | 2024 |
| Mulberry Tree Enterprises Ltd | Hospitality | 2017 |
| N & P Services Limited | Information & communication | 2004 |
| N. J. Ford Limited | Agriculture & fishing | 2002 |
| N.S.Glover Prosthodontics Ltd | Health & social care | 2026 |
| Nabee Properties Limited | Real estate | 2024 |
| Naiad Property Limited | Real estate | 2020 |
| Nationwide Home Innovation Holdings Ltd | Financial services | 2017 |
| Nationwide Home Innovations EOT Limited | Financial services | 2025 |
| Nationwide Home Innovations Limited | Administrative & support | 2008 |