| Midwinters Agricultural Services Limited | Manufacturing | 2003 |
| Mienterprise Herefordshire Community Interest Company | Other services | 2007 |
| Mike Bufton Building & Electrical Services Ltd | Construction | 2022 |
| Mike Thomas International Limited | Professional & scientific | 2016 |
| Milners Marine Ltd | Manufacturing | 2019 |
| Milton Resources Limited | Manufacturing | 1999 |
| Minera Gardens Management Company Ltd | Other services | 2016 |
| Minster Auctions Limited | Wholesale & retail | 2020 |
| Mission Control Motosports Limited | Wholesale & retail | 2007 |
| MJ Evans Fencing Ltd | Construction | 2016 |
| Mjhairpalace UK Ltd | Households | 2024 |
| MJN Design Limited | Arts & recreation | 2007 |
| ML Forestry Ltd | Agriculture & fishing | 2014 |
| MM Electrical Services (Hereford) Limited | Construction | 2006 |
| Mobile Office Solutions Limited | Extraterritorial | 1998 |
| Modular Industrial Automation Limited | Manufacturing | 2025 |
| Mona Careers Limited | Administrative & support | 2023 |
| Monkland Cheesemakers Ltd | Manufacturing | 2023 |
| Monkland Mowers & Machinery Ltd | Manufacturing | 2025 |
| Monkton Consultants Ltd | Professional & scientific | 2015 |
| Montclair Holdings Ltd | Financial services | 2025 |
| Montrose Industries Limited | Mining & quarrying | 1960 |
| Monty DON Ltd | Professional & scientific | 2005 |
| Monty’S Drinks Ltd | Manufacturing | 2025 |
| Mooba Consultancy Limited | Professional & scientific | 2011 |
| Mortimer Equine Vets Ltd. | Professional & scientific | 2019 |
| Mortimer Homecare Limited | Other services | 2016 |
| Mortimer Press Limited | Information & communication | 2005 |
| Mortimer Vets Ltd. | Professional & scientific | 2023 |
| Moseley Pools Limited | Real estate | 2021 |
| Moss Holdings Limited | Professional & scientific | 2022 |
| Move This Way Ltd | Extraterritorial | 2000 |
| MPB Home Maintenance Ltd. | Construction | 2014 |
| MPS Holdings Limited | Professional & scientific | 1997 |
| MR Duro Ltd | Wholesale & retail | 2025 |
| MS Pipework Ltd | Construction | 2009 |
| MS Weaver Limited | Construction | 2014 |
| MT LEO Properties Ltd | Real estate | 2026 |
| MUD Rugs Ltd | Wholesale & retail | 2019 |
| Mulberry Meadow Yarpole Management Company Limited | Households | 2021 |
| Murecho Ltd | Information & communication | 2021 |
| Mycotech Supplies Ltd | Manufacturing | 2023 |
| N J Caine Limited | Real estate | 2008 |
| N R Bennett Ltd | Professional & scientific | 2002 |
| N.V. Hall and SON Limited | Real estate | 1982 |
| National Equine Forum | Administrative & support | 2011 |
| National Flooring Contractors Ltd | Construction | 2016 |
| Natural Paint UK Limited | Manufacturing | 2017 |
| Nature's Secrets Cosmetics Limited | Manufacturing | 1983 |
| Nevara Properties Ltd | Real estate | 2026 |
| New Vision Services Limited | Information & communication | 2018 |
| Newchurch Farms Limited | Agriculture & fishing | 1982 |
| Nick Hughes Architectural Consultant Ltd | Professional & scientific | 2026 |
| Nick Wells Consulting Ltd | Professional & scientific | 2026 |
| NIL Admirari Limited | Wholesale & retail | 2014 |
| NJS Projects Ltd | Real estate | 2020 |
| NO. Thirty - Four Limited | Households | 1998 |
| Nodrog Holdings Ltd | Real estate | 2017 |
| Nomad Leisure Limited | Hospitality | 2010 |
| Nomad Securities Limited | Financial services | 2020 |
| Nordan Maintenance Services Ltd | Administrative & support | 2011 |
| Norman Bros (the Leen) Ltd | Agriculture & fishing | 2013 |
| Novartas Limited | Professional & scientific | 2012 |
| NRB Secretaries Ltd | Administrative & support | 2010 |
| Nu-Tree Ltd | Extraterritorial | 2013 |
| Nuelle Ltd | Wholesale & retail | 2025 |
| Nunoou Ltd | Health & social care | 2025 |
| Nurture Medical Group Ltd | Education | 2024 |
| O&A Business Ltd | Other services | 2026 |
| Oak Tree Drive (Westcroft) Management Company Ltd | Households | 2019 |
| Oaker Wood Leisure Limited | Arts & recreation | 2000 |
| Occam's Razor Limited | Information & communication | 1996 |
| Octopus Business Solutions Ltd | Extraterritorial | 2014 |
| Odell CQS2 Ltd | Professional & scientific | 2025 |
| OFF the Shelf Publishing Limited | Information & communication | 2012 |
| OG Security Ltd | Administrative & support | 2022 |
| OH Flora Limited | Wholesale & retail | 2017 |
| OJT Communications Limited | Information & communication | 2009 |
| Old Hall Bespoke Ltd | Manufacturing | 2024 |
| Old Hill Willow Ltd | Manufacturing | 1987 |
| Oldfield Systems Limited | Administrative & support | 2001 |
| Oldfields Garage Services Ltd | Wholesale & retail | 2012 |
| Oldfields Property Co Limited | Real estate | 2024 |
| One Vision School of Arts Ltd | Arts & recreation | 2018 |
| OP Apollo Ltd | Administrative & support | 2025 |
| Opportunities for Adventure,Knowledge and Skills Ltd | Education | 2009 |
| Opsense Healthcare Limited | Health & social care | 2023 |
| Origins Football CIC | Arts & recreation | 2025 |
| Orphans Press Limited | Manufacturing | 1975 |
| OTS Business Ltd | Other services | 2024 |
| OWC Ltd | Wholesale & retail | 2019 |
| Owens Poultry Ltd | Agriculture & fishing | 2026 |
| Oxford Comma Digital Ltd | Professional & scientific | 2022 |
| P a P Pearson Limited | Professional & scientific | 2020 |
| P J Refrigeration Ltd | Manufacturing | 2014 |
| P&S Short Holdings Limited | Real estate | 2017 |
| Paloma Enterprises Limited | Other services | 2014 |
| Panels & Profiles Group Limited | Manufacturing | 2013 |
| Paper Boating Ltd | Information & communication | 2026 |
| Park Mews Management - Weymouth Ltd | Households | 2013 |