| Luffman Holdings Ltd | Financial services | 2023 |
| Luffman Plant Ltd | Manufacturing | 2008 |
| Luja Holdings Ltd | Real estate | 2020 |
| Lumea Holdings Ltd | Financial services | 2023 |
| Lumea Ltd | Wholesale & retail | 2001 |
| Lumea Trustee Company Limited | Financial services | 2025 |
| Lurley Hideaways Ltd | Hospitality | 2025 |
| Lusp Holdings Ltd | Financial services | 2025 |
| Luttrell Farm Limited | Agriculture & fishing | 2009 |
| Luxton Court (Cullompton) Management Company Limited | Households | 2004 |
| Lythecourt Management Company Limited | Real estate | 2003 |
| M & C Farrell Limited | Real estate | 2016 |
| M & K Property (SW) Ltd | Real estate | 2024 |
| M a B Construct Limited | Construction | 2013 |
| M Orchard Trading Limited | Wholesale & retail | 2021 |
| M Tester & S Edwards Ltd | Agriculture & fishing | 2024 |
| M&P Lambert HLA Ltd | Administrative & support | 2025 |
| M&P Lambert Holdings Ltd | Financial services | 2025 |
| M&P Lambert Lending Ltd | Financial services | 2025 |
| M&P Lambert Properties Ltd | Real estate | 2025 |
| M&R Caravans Ltd | Wholesale & retail | 2024 |
| M. Holland Construction Limited | Construction | 2004 |
| M.J.Z Electrical Limited | Construction | 2025 |
| M.W. Greenslade Ltd | Construction | 2011 |
| MA Systems Limited | Information & communication | 2019 |
| MAA Holdings Limited | Professional & scientific | 2007 |
| MAC Holdings (SW) Limited | Professional & scientific | 2011 |
| MAC Tracks Ltd | Wholesale & retail | 2007 |
| Macbeth Limited | Construction | 1996 |
| Machell Orthodontics Limited | Health & social care | 2020 |
| Machine Direct Limited | Wholesale & retail | 2014 |
| Maggie B'S Limited | Health & social care | 2025 |
| Maggie Services Limited | Real estate | 1984 |
| Magpies Cafe Ltd | Hospitality | 2022 |
| Malthouse Management (Cullompton) Limited | Households | 2023 |
| Malvern Heights Limited | Real estate | 2023 |
| Manazel Ltd | Real estate | 2014 |
| Mango Mansions Limited | Real estate | 2026 |
| Manley Holdings Limited | Real estate | 2015 |
| Mantonhigh Property Management Limited | Real estate | 1986 |
| Many Saints Ltd | Wholesale & retail | 2023 |
| Marbles Cleaning Limited | Administrative & support | 2008 |
| Marcus Ridley Associates Limited | Health & social care | 1998 |
| Marigold Apartments Hayne Farm (Gittisham) Limited | Households | 2019 |
| Marine Parade (Appledore) Management Company Limited | Households | 1998 |
| Mariner's Haven Management Limited | Households | 2024 |
| Mark Fisher Carpenter and Builder Ltd | Construction | 2003 |
| Mark Poltimore Art Consultancy Limited | Arts & recreation | 2024 |
| Marshay Farm Limited | Agriculture & fishing | 2020 |
| Martin 6367 Ltd | Real estate | 2018 |
| Martin Burnett Contractors Limited | Administrative & support | 2007 |
| Martin Wickens Furniture Limited | Construction | 2002 |
| Martyn Baker Livestock Ltd. | Transport & logistics | 2003 |
| Masons Farm and Country Limited | Wholesale & retail | 2004 |
| Master Plumb Solutions Limited | Construction | 2025 |
| Mathews Vehicle Solutions Ltd | Wholesale & retail | 2023 |
| Matrix Film Finance LLP | | 2003 |
| Matrix Partnership Management LLP | | 2012 |
| Matrix Structured Finance LLP | | 2006 |
| Matt Coffey Civil Solutions Ltd | Construction | 2022 |
| Mavi Deniz (UK) Ltd | Professional & scientific | 2006 |
| MAW Works Ltd | Construction | 2025 |
| MAX Berry Productions Limited | Information & communication | 2018 |
| MAX Electrical S.W. Ltd | Manufacturing | 2016 |
| MAX Solar & Electrical Ltd | Construction | 2024 |
| Mayfield Laboratories Limited | Professional & scientific | 2003 |
| Mazzard View Phase 1 Management Company Limited | Households | 2017 |
| MB Road Haulage Ltd | Transport & logistics | 2024 |
| MBM Enterprises Devon Limited | Agriculture & fishing | 2018 |
| Mcfisher Ltd | Hospitality | 2025 |
| Mcubus Ltd | Information & communication | 2023 |
| MD Fish Tanks Limited | Information & communication | 2021 |
| Mdbp Estate Management Limited | Households | 2016 |
| Meade House Limited | Real estate | 2023 |
| Meadow View Open Space Management Company Limited | Households | 2013 |
| Meaningful Media Ltd | Information & communication | 2014 |
| Media Business Projects Ltd | Information & communication | 2012 |
| Medsensica Ltd | Professional & scientific | 2024 |
| Meilleur Care Ltd | Health & social care | 2018 |
| Membership Services Ltd | Professional & scientific | 2018 |
| MEP Textile LLP | | 2020 |
| Merryfield Associates Ltd | Professional & scientific | 2024 |
| Merryfieldhayes Limited | Professional & scientific | 2002 |
| MGR Music Tuition Ltd | Other services | 2013 |
| MH Building Limited | Construction | 2021 |
| Mhpd Property Limited | Real estate | 2025 |
| MID Devon Glass Holdings Limited | Financial services | 2025 |
| MID Devon Homes Ltd | Construction | 2022 |
| MID Devon Indoor Bowls Centre Limited | Arts & recreation | 1993 |
| MID Devon Metals Limited | Wholesale & retail | 2025 |
| MID Devon Mobility | Transport & logistics | 2003 |
| MID Devon Mobility Trading Limited | Transport & logistics | 2019 |
| MID Devon Town and Country Show Society | Education | 1993 |
| Middle North Coombe Farm Limited | Agriculture & fishing | 2005 |
| Midline Estates Ltd | Real estate | 2006 |
| Migri Ltd | Hospitality | 2016 |
| MILIFE365 Ltd | Professional & scientific | 2022 |
| Milk 1 Sugar Building Works Ltd | Construction | 2024 |
| Milk Pet Foods Ltd | Manufacturing | 2024 |
| Milkfortoast Ltd | Information & communication | 2015 |