| Land and Wave Ltd | Arts & recreation | 2009 |
| Langdale Boundary Investments Limited | Financial services | 2024 |
| Langdale Boundary LLP | | 2012 |
| Lapvent Ltd | Wholesale & retail | 2010 |
| Lateralize Ltd | Administrative & support | 2017 |
| Launspach Property Company Limited | Real estate | 1961 |
| LCE Expert Witness Services Limited | Health & social care | 2021 |
| LES Bouviers Restaurants Limited | Hospitality | 1995 |
| Levey Construction Limited | Construction | 2007 |
| Lexcourt Limited | Hospitality | 2016 |
| Light the Truth Ltd | Arts & recreation | 2021 |
| Limefrog Ltd | Construction | 2020 |
| Limeworks (Wessex) Limited | Extraterritorial | 2013 |
| Lindfield Consultants Ltd | Professional & scientific | 2009 |
| Lion Swanage Limited | Hospitality | 2025 |
| Littlebirds Home and Holiday Services Ltd | Administrative & support | 2020 |
| Locksmiths Freeholders Ltd | Hospitality | 2007 |
| Loft Tech Work Ltd | Construction | 2024 |
| Logon-Woodburners Ltd | Wholesale & retail | 2011 |
| Longhouse Residents Association Ltd | Households | 2023 |
| Longshore Digital Ltd | Information & communication | 2025 |
| Lovell and Barnes Limited | Wholesale & retail | 2003 |
| Lucid Services Ltd | Construction | 2022 |
| Lucy's Farm Shop Ltd | Wholesale & retail | 2018 |
| Luke Diaper Brickwork Ltd | Construction | 2017 |
| Lynden Hall Management Co. Limited | Households | 1992 |
| M a Gillespie Ltd | Construction | 2014 |
| M a Rainback Limited | Manufacturing | 2002 |
| M a Timber Construction Ltd | Administrative & support | 2005 |
| M H Draughting Services Ltd | Professional & scientific | 2002 |
| M L Technology Limited | Professional & scientific | 1999 |
| M M Carpentry (Southern) Ltd | Construction | 2019 |
| M R Innovations Ltd | Professional & scientific | 2021 |
| M-Ocean Composites Ltd | Manufacturing | 2022 |
| M-Ocean Group Ltd | Manufacturing | 2022 |
| M-Ocean Marine Ltd | Manufacturing | 2022 |
| M. R. Jones Holdings Limited | Real estate | 2023 |
| Macrow and SON Ltd | Wholesale & retail | 2001 |
| Madd Flow Ltd | Professional & scientific | 2019 |
| Madison Beauty Limited | Other services | 2016 |
| Magic Barber One Ltd | Other services | 2026 |
| Mainline Safety Solutions Limited | Professional & scientific | 2006 |
| Mandi Mart Limited | Wholesale & retail | 2014 |
| Manor Gardens Freehold (Swanage) Company Limited | Professional & scientific | 2005 |
| Manor Gardens Management Company (Swanage) Limited | Households | 1984 |
| Marina View Management Limited | Households | 1995 |
| Marine Solutions South Ltd | Other services | 2009 |
| Mariner's Watch Residents Association Limited | Households | 1983 |
| Marston Property (Dorset) Ltd | Construction | 2026 |
| Martin Judd Ltd | Construction | 2005 |
| Masala Indian Cuisine (Swanage) Limited | Hospitality | 2003 |
| Matom Holdings Limited | Financial services | 2022 |
| Matom Properties Limited | Real estate | 2022 |
| Matthew Turner Plumbing and Heating Limited | Construction | 2011 |
| Mayfield and Weyhill Management Company Limited | Households | 2009 |
| MB Martial Arts Ltd | Education | 2022 |
| Mbtoo Limited | Financial services | 2022 |
| Mcdonald & Sons (Swanage) Ltd | Construction | 2005 |
| Media Finance Limited | Professional & scientific | 2004 |
| Medway Systems Limited | Other services | 2016 |
| Mellows Holdings Ltd | Financial services | 2022 |
| Mellows Property Ltd | Real estate | 2022 |
| Melsan Court Management Co. Ltd | Households | 1987 |
| MEP Concepts Limited | Professional & scientific | 2012 |
| Mermond Place Management Ltd | Households | 2021 |
| Merrick Plasterers Ltd | Construction | 2001 |
| Merry Holdings Limited | Financial services | 2019 |
| Merry Properties Limited | Real estate | 2019 |
| Mesele Ltd | Hospitality | 2022 |
| Messages Ltd | Extraterritorial | 2008 |
| Metro Communications Ltd | Information & communication | 2015 |
| Michael Odam Lighting Design Limited | Manufacturing | 2003 |
| Millbrook Guesthouse Ltd | Hospitality | 2003 |
| Minterne 1993 Limited | Households | 1993 |
| MJ Steel Holdings Limited | Households | 2026 |
| MKL Accountants Limited | Professional & scientific | 2002 |
| MKL Limited | Professional & scientific | 2004 |
| MKL Secretaries Limited | Professional & scientific | 2001 |
| MNJ Developments Limited | Real estate | 2004 |
| Moon Rules Ltd | Hospitality | 2024 |
| Moonfleet Cars Ltd | Wholesale & retail | 2018 |
| Morepork Limited | Professional & scientific | 2010 |
| Moto Leasing Ltd | Administrative & support | 2012 |
| Mouland Plastering Ltd | Construction | 2019 |
| Mowlem Court (Swanage) Limited | Professional & scientific | 1985 |
| MSB Lifestyles Ltd | Real estate | 2010 |
| Muhammad Amjad Ltd | Wholesale & retail | 2025 |
| My Kind of Thinking Ltd | Education | 2021 |
| N B Plant (South) Ltd | Construction | 2018 |
| Nano Nano Ltd | Information & communication | 2015 |
| NAP Commercial Ltd | Real estate | 2022 |
| Nara Corfe Castle Ltd | Wholesale & retail | 2023 |
| Naurex Limited | Professional & scientific | 2009 |
| Naurex Technical Services Limited | Administrative & support | 2013 |
| NBN Global Ltd | Other services | 2026 |
| NE Investors LLP | | 2007 |
| NET Sensors Ltd | Manufacturing | 2017 |
| NET Zero Design & Build Ltd | Construction | 2022 |
| Network Registration Services Limited | Other services | 2017 |
| Network Testers Ltd | Extraterritorial | 2018 |