| Mells Creative Ltd | Professional & scientific | 2022 |
| Mend and Tend Limited | Manufacturing | 2009 |
| Mendip & Somerset Construction Limited | Construction | 2024 |
| Mendip Bookkeeping Ltd | Professional & scientific | 2018 |
| Mendip Car Company Ltd | Wholesale & retail | 2021 |
| Mendip Care Ltd | Public administration | 2019 |
| Mendip Farmers' Hunt Fallen Stock Limited | Agriculture & fishing | 2014 |
| Mendip Fireplaces (Somerset) Limited | Wholesale & retail | 2018 |
| Mendip Fireplaces Ltd | Wholesale & retail | 2003 |
| Mendip Gliding Club Limited | Arts & recreation | 1983 |
| Mendip Plains Equestrian Centre Limited | Administrative & support | 2010 |
| Mendip Print Solutions Limited | Wholesale & retail | 2002 |
| Mendip Rural Services Ltd | Other services | 2013 |
| Mendip Shooting Ground Limited | Arts & recreation | 2012 |
| Mendip Wealth Management Ltd | Professional & scientific | 2023 |
| Mercia Endeavours Ltd | Wholesale & retail | 2018 |
| Mercury Financial Consultants Limited | Professional & scientific | 2013 |
| Merlin Car & Commercial Limited | Wholesale & retail | 2007 |
| Methodology Production Ltd | Professional & scientific | 2019 |
| Mewse Holdings Limited | Financial services | 2024 |
| Mfbprestige Ltd | Wholesale & retail | 2025 |
| MG Development Limited | Real estate | 2006 |
| MI Thai Ltd | Hospitality | 2019 |
| Microlink Devices UK Ltd | Manufacturing | 2019 |
| Middle Thrupe Water Ltd | Other services | 2023 |
| Middlefield Developments Ltd | Real estate | 2015 |
| Milk Station Ltd | Wholesale & retail | 2018 |
| Mill Place (Shaftesbury) Management Company Limited | Administrative & support | 1996 |
| Mill Street Business Centre Limited | Extraterritorial | 2015 |
| Millard Poultry Limited | Agriculture & fishing | 2003 |
| Milli Optical Ltd | Professional & scientific | 2025 |
| Millican Rentals Ltd | Real estate | 2025 |
| Milton Field Sports Limited | Agriculture & fishing | 2006 |
| Mine & Quarry UK Ltd | Mining & quarrying | 2019 |
| Minton Architects Limited | Real estate | 1993 |
| Minton Associates Limited | Professional & scientific | 1989 |
| Minton Developments (Mansfield) Limited | Construction | 2017 |
| Minton Management Limited | Financial services | 2017 |
| MJ Consultancy (South West) Limited | Professional & scientific | 2025 |
| Mjcompton Limited | Professional & scientific | 2026 |
| MK Minerals Ltd | Health & social care | 2015 |
| ML & N Stott Contracting Limited | Agriculture & fishing | 2018 |
| MM Premium Property Ltd | Real estate | 2025 |
| Modern Construction Limited | Construction | 2009 |
| Modular Engineering Concepts Ltd | Professional & scientific | 2017 |
| Mondrian Technical Ltd | Wholesale & retail | 2017 |
| Moneta Wealth Management Limited | Financial services | 2011 |
| Money in Muck Limited | Real estate | 2022 |
| Monkey Puzzle Kitchens and Furniture Limited | Manufacturing | 2016 |
| Monument Site Management Ltd | Construction | 2020 |
| Moorland Management and Maintenance Limited | Construction | 2026 |
| Moot Management Consulting Ltd | Professional & scientific | 2015 |
| Morgan Credit Energy Wales Limited | Administrative & support | 2010 |
| Moroccan and Yummy Ltd | Manufacturing | 2016 |
| Morocco Mole Ltd | Administrative & support | 2021 |
| Mortgage & Financial Planning (Wells) Ltd | Financial services | 2014 |
| Mpsu Ltd | Professional & scientific | 2018 |
| MR Pastry Ltd | Manufacturing | 2015 |
| MRG Compliance Consultancy Limited | Professional & scientific | 2012 |
| Msal Ltd | Wholesale & retail | 2023 |
| MTL Group Ltd | Professional & scientific | 2014 |
| Muise Management Ltd | Information & communication | 2022 |
| Murphy's Cleaning Agency Ltd | Administrative & support | 2025 |
| My Holiday Place Limited | Extraterritorial | 2016 |
| My Support and Care Services (West Country) Limited | Health & social care | 2013 |
| Myrtle Court Management Limited | Households | 2006 |
| N & C Parfitt Limited | Wholesale & retail | 2011 |
| N B Tree Services Ltd | Administrative & support | 2021 |
| N G Barham Building Services Ltd | Construction | 2013 |
| N J Cavill Limited | Construction | 2014 |
| N.B. Illustration Limited | Administrative & support | 2000 |
| National Vehicle Delivery Services Ltd | Transport & logistics | 2020 |
| Natural Education Works C.I.C. | Agriculture & fishing | 2025 |
| Naughty Tiger Ltd | Professional & scientific | 2018 |
| Naval Solutions Ltd | Professional & scientific | 2019 |
| Naxos Creative Ltd | Education | 2022 |
| NDM Surveyors Limited | Professional & scientific | 2000 |
| Ndpc Technology Ltd | Wholesale & retail | 2025 |
| Neil Bees Groundworks Ltd | Construction | 2017 |
| Net-Zero 4 Business Limited | Information & communication | 2022 |
| Netpilot Global Limited | Information & communication | 2017 |
| Network Stages Ltd | Arts & recreation | 2024 |
| Neuman Lighting Design Ltd | Professional & scientific | 2009 |
| Neva Developments Ltd | Construction | 2017 |
| New Fruit Productions Limited | Information & communication | 2016 |
| New Leaf Weight Loss Solutions Ltd | Health & social care | 2014 |
| New Synthetic Theatre Ltd | Arts & recreation | 2012 |
| Newton Peak Limited | Financial services | 2025 |
| Nick Dyer Plastering Ltd | Construction | 2012 |
| Nick`S Shoes Ltd | Agriculture & fishing | 2009 |
| Nigelmarks Ltd | Professional & scientific | 2005 |
| Ninfa Investments Ltd | Financial services | 2016 |
| NJB Executive Cars Ltd | Transport & logistics | 2013 |
| Noble Ebme Limited | Professional & scientific | 2021 |
| Nordic Heart Studios Ltd | Other services | 2022 |
| Nordic Offsite Limited | Professional & scientific | 2013 |
| Norfolk & Boss Limited | Manufacturing | 2017 |
| Norlight Ltd | Manufacturing | 2022 |
| North Dairy Farms Limited | Agriculture & fishing | 1991 |
| North Grove Associates Ltd | Professional & scientific | 2024 |