| Mendip ICA Limited | Manufacturing | 2016 |
| Mendip Maintenance Ltd | Construction | 2024 |
| Mendip Medical Ltd | Health & social care | 2017 |
| Mendip Sticks Limited | Manufacturing | 2018 |
| Mendip Swim Limited | Arts & recreation | 2021 |
| Mendip Windows Limited | Construction | 1988 |
| Mercury Secured Mail Limited | Extraterritorial | 2011 |
| Mercury Workflow Solutions Limited | Extraterritorial | 2010 |
| Merlin Studios Ltd | Professional & scientific | 2023 |
| Mesda Ltd | Professional & scientific | 2017 |
| Meshaw Investments Ltd | Real estate | 2024 |
| Mesopotamia Medicals Limited | Health & social care | 2017 |
| Metabolic Movement Ltd | Arts & recreation | 2018 |
| Meticulous Stitching and Design Ltd | Manufacturing | 2024 |
| Metrics Retails Ltd | Wholesale & retail | 2020 |
| Metta Theatre Limited | Arts & recreation | 2010 |
| MGC Catering Limited | Hospitality | 2021 |
| Mhpa Hire Limited | Arts & recreation | 2020 |
| Miafood Ltd | Hospitality | 2024 |
| MIB Electronic Ltd | Manufacturing | 2012 |
| Michco 1204 Limited | Energy | 2012 |
| Michco 1205 Limited | Energy | 2012 |
| Michco 1208 Limited | Professional & scientific | 2012 |
| Micro Cloud Accountancy Ltd | Professional & scientific | 2018 |
| Micro Tool Hire Limited | Water & waste | 2021 |
| Micro-Membrane Systems Limited | Manufacturing | 2003 |
| Microporous Products Limited | Wholesale & retail | 2012 |
| Midsomer Beauty Salon Ltd | Other services | 2010 |
| Midsomer Magpie Ltd | Wholesale & retail | 2024 |
| Midsomer Norton & District Carnival Charity Association | Arts & recreation | 1999 |
| Midsomer Norton & Radstock Dial a Ride | Administrative & support | 2004 |
| Midsomer Norton Schools Partnership | Education | 2010 |
| Midsomer Quilting Ltd | Wholesale & retail | 2022 |
| Midsomer Science Limited | Professional & scientific | 2019 |
| Midsomer Solartech Limited | Construction | 2011 |
| Midway Farm Dairy Ltd | Manufacturing | 2020 |
| Miles Weber Architect Limited | Professional & scientific | 2015 |
| Millards Court Management Company Limited | Households | 1996 |
| Miller Building & Renovation Ltd | Construction | 2012 |
| Milliner Court (Shepton Mallet) Management Company Limited | Households | 2002 |
| Mills Engineering Design & Surveying Ltd | Professional & scientific | 2025 |
| Mills Engineering Services Limited | Manufacturing | 2009 |
| Mills Holdings Southwest Limited | Real estate | 2026 |
| Milo Reid Studio Limited | Professional & scientific | 2019 |
| Milton House (Bath) Limited | Transport & logistics | 2012 |
| Mindx Global Ltd | Health & social care | 2023 |
| Mine Quarry Motorsport Limited | Mining & quarrying | 2006 |
| Minerva Exhibitions Limited | Administrative & support | 2017 |
| Mirant Software Ltd | Information & communication | 2024 |
| MJG Associates Limited | Professional & scientific | 2002 |
| MK Business Services Ltd | Information & communication | 2025 |
| MLH SET Carpentry Limited | Construction | 2015 |
| MMA Architectural Matting Limited | Wholesale & retail | 2024 |
| MMA Architectural Systems Limited | Wholesale & retail | 2007 |
| MMX Solutions Limited | Information & communication | 2010 |
| Mobius Solutions Limited | Professional & scientific | 2024 |
| Mobque Ltd | Hospitality | 2023 |
| Molofox Ltd | Information & communication | 2024 |
| Monopoly Limited | Real estate | 2001 |
| Monster Press Limited | Manufacturing | 2014 |
| Montesion (UK) Limited | Wholesale & retail | 2024 |
| Moose Roper Limited | Construction | 2005 |
| Morgans Plant Machinery Ltd. | Construction | 2014 |
| Mostly Books (Abingdon) Ltd | Wholesale & retail | 2016 |
| Motor Brew Co Ltd | Wholesale & retail | 2026 |
| Motorvet Ltd | Professional & scientific | 2025 |
| Mountain and Forest Outdoor Education Company Limited | Education | 2012 |
| Move the Mind Learning AP Ltd | Education | 2025 |
| Movesense Residents Association Limited | Real estate | 1984 |
| Moving Property Ltd | Real estate | 2006 |
| Mowhay Limited | Other services | 2019 |
| MP Holiday Lodges Limited | Real estate | 2023 |
| MR (Bristol) Limited | Administrative & support | 2003 |
| MSN Cars Ltd | Wholesale & retail | 2025 |
| MSW Data Ltd | Information & communication | 2024 |
| Muckoffmats Limited | Wholesale & retail | 2023 |
| Muse Coffee Shop Ltd | Hospitality | 2024 |
| Musicala Limited | Information & communication | 2022 |
| My Part Time FD Limited | Professional & scientific | 2021 |
| My Wild Things Ltd | Wholesale & retail | 2021 |
| My-Thesis CIC | Education | 2026 |
| N J Penney Limited | Construction | 1997 |
| N Walker Services Ltd | Information & communication | 2026 |
| N&J Developments SW Ltd | Real estate | 2024 |
| N. J. Maggs Funeral Service Ltd | Other services | 2024 |
| N.B. Sellar Limited | Wholesale & retail | 2005 |
| National Traction Engine Club (1984) Limited | Extraterritorial | 1984 |
| National Traction Engine Trust | Arts & recreation | 1977 |
| Nauvoo Capital Limited | Real estate | 2015 |
| NC Building and Landscaping Ltd | Construction | 2022 |
| NDT & Inspection UK Limited | Professional & scientific | 2023 |
| Nebula Commercial Solutions Ltd | Information & communication | 2015 |
| Neil Brown Limited | Wholesale & retail | 2005 |
| Nemco Global Limited | Financial services | 2026 |
| Neptune & Juniper Ltd | Real estate | 2024 |
| Nereus World Limited | Professional & scientific | 2002 |
| NET Zero One Ltd | Energy | 2021 |
| NET Zero Three Ltd | Energy | 2021 |
| NET Zero Two Ltd | Energy | 2021 |
| Nevara Coaching Ltd | Arts & recreation | 2026 |