| MIX & Match Housing Ltd | Real estate | 2021 |
| Miyagi Consulting Limited | Professional & scientific | 2026 |
| Mizgin Limited | Hospitality | 2025 |
| MJ Goodwin & AJ Brown Ltd | Agriculture & fishing | 2025 |
| MJ Wargen Training Ltd | Construction | 2015 |
| MJS Dental Ltd | Health & social care | 2026 |
| MKB Bodyshop Limited | Wholesale & retail | 2024 |
| MKB Vehicle Hire Limited | Administrative & support | 2025 |
| Mkri Limited | Financial services | 2021 |
| MLP Property Limited | Real estate | 2020 |
| MM & CM Limited | Professional & scientific | 2014 |
| Mminimal Ltd | Wholesale & retail | 2015 |
| MML Portfolio Ltd | Real estate | 2023 |
| MML Project Management Ltd | Construction | 2019 |
| MNF Solutions Limited | Water & waste | 2024 |
| Mobile Care & Domestic Services Ltd | Health & social care | 2013 |
| Mobile-Mechanic-Service Hereford Ltd | Wholesale & retail | 2020 |
| Moccas Estate Property Limited | Construction | 2007 |
| Moda Swansea Limited | Wholesale & retail | 2010 |
| Mode 13 Limited | Administrative & support | 2013 |
| Modelcraft UK Ltd | Manufacturing | 2003 |
| Models and Miniatures of Hereford Ltd | Wholesale & retail | 2016 |
| Modern Facades Detailing Services Limited | Professional & scientific | 2020 |
| Modern for YOU Ltd | Construction | 2014 |
| Modern Gateway Solutions Ltd | Professional & scientific | 2026 |
| Moka Bar Ltd | Hospitality | 2011 |
| Mold Masters (UK) Limited | Manufacturing | 1985 |
| Mollison Holdings Ltd | Financial services | 2023 |
| Molnar Property Limited | Real estate | 2021 |
| Mona Staff Ltd | Administrative & support | 2024 |
| Moneypeak Limited | Agriculture & fishing | 2001 |
| Moneytree Mortgages Ltd | Professional & scientific | 2019 |
| Monlam Properties Ltd | Real estate | 2023 |
| Monmouth & Ross-On-Wye Self Storage Ltd | Extraterritorial | 2015 |
| Monnow Valley Holdings Ltd | Financial services | 2019 |
| Monolith Homes Limited | Construction | 2024 |
| Mons Star Limited | Information & communication | 2008 |
| Monsaltus Ltd | Real estate | 2023 |
| Montez Architecture Ltd | Professional & scientific | 2018 |
| Montvernier Limited | Financial services | 2021 |
| Monument Court (Hereford) Property Company Limited | Households | 2021 |
| Mood Matters at Home Limited | Extraterritorial | 2011 |
| Moon Park Ltd | Education | 2025 |
| Moona Health Limited | Information & communication | 2024 |
| Moonraker Field Limited | Real estate | 2014 |
| Moonrise Media Ltd | Information & communication | 1992 |
| Moorings and Moor Worldwide Limited | Wholesale & retail | 2011 |
| Moorscape P.M. Limited | Real estate | 2024 |
| Mooshine Ltd | Manufacturing | 2018 |
| Mordiford Church of England Primary School | Education | 2013 |
| More Creative Studio Ltd | Professional & scientific | 2018 |
| More Escapes Ltd | Hospitality | 2019 |
| More Interiors Limited | Construction | 2017 |
| More OR Less Everything Ltd | Transport & logistics | 2011 |
| Moreton Specialist Security Associates Limited | Professional & scientific | 2017 |
| Moreton View Nurseries Ltd | Wholesale & retail | 2014 |
| Morgan Curtis Properties Limited | Real estate | 2017 |
| Morgan Spain Limited | Real estate | 2015 |
| Morgan Vickers Consulting Ltd | Professional & scientific | 2021 |
| Morris Construction & Joinery Ltd | Construction | 2017 |
| Mortimer House Properties Ltd | Real estate | 2019 |
| Mortimer Projects Limited | Construction | 2006 |
| Moth Creaturae Ltd | Wholesale & retail | 2019 |
| Mother Fudge Crackers Ltd | Wholesale & retail | 2024 |
| Motion 3D Media Ltd | Information & communication | 2023 |
| Motion Business Group Ltd | Financial services | 2023 |
| Motion Joint Ventures Ltd | Financial services | 2023 |
| Motion Real Estate Media Ltd | Professional & scientific | 2019 |
| Motion Site Services Ltd | Construction | 2024 |
| Motomums Ltd | Wholesale & retail | 2025 |
| Mountain Law Limited | Administrative & support | 2019 |
| Mountain Mayhem Limited | Arts & recreation | 2003 |
| Mountain View Regenerative Farm Ltd | Agriculture & fishing | 2023 |
| Mousetrap Cheese Limited | Administrative & support | 2017 |
| Mousle Properties Ltd | Real estate | 2015 |
| MPD Transport Solutions Ltd | Transport & logistics | 2025 |
| MPJ Bakery & Confections Ltd | Manufacturing | 2003 |
| Mpntransport Ltd | Transport & logistics | 2022 |
| MPT Events Limited | Hospitality | 2025 |
| MR Clean (Hereford) Limited | Administrative & support | 2008 |
| MR LEE Solutions Limited | Administrative & support | 2025 |
| Mr.Gyro Ltd | Hospitality | 2022 |
| MRB (Hereford) Ltd | Manufacturing | 2014 |
| MRG Building & Developments Ltd | Construction | 2023 |
| MRJ Fabrication Services Ltd | Manufacturing | 2018 |
| Mrpa Holdings Limited | Professional & scientific | 2015 |
| MS Legacy Homes Ltd | Real estate | 2025 |
| MS Legacy Properties Ltd | Real estate | 2024 |
| MS Resource Group Ltd | Administrative & support | 2020 |
| Ms&H Limited | Health & social care | 2023 |
| MSB Properties Hereford Limited | Real estate | 2023 |
| MSE Interviews Ltd | Education | 2025 |
| MSO Advisors Limited | Professional & scientific | 2012 |
| MSP Solutions Limited | Real estate | 2004 |
| Much Birch Garage Limited | Wholesale & retail | 2008 |
| Mugshot Barber Ltd | Other services | 2022 |
| Multi Engineering Solutions Ltd | Manufacturing | 2018 |
| Munchies HFD Ltd | Hospitality | 2019 |
| Munday Taylor Lamont Limited | Construction | 2008 |
| Munro's Holdings Limited | Real estate | 2025 |