| MIA Property Holdings Ltd | Real estate | 2025 |
| Michael Timber Landscaping Limited | Administrative & support | 2024 |
| Micron Aluminium Doors Limited | Extraterritorial | 2014 |
| Micron Conservatories Windows and Doors Limited | Extraterritorial | 2014 |
| Micron Holdings Limited | Real estate | 1971 |
| Micron Home Improvements Limited | Extraterritorial | 2014 |
| Midlands Building & Maintenance Limited | Construction | 2017 |
| Mike's Mowers Tewkesbury Ltd | Manufacturing | 2023 |
| Miles Ahead Property Solutions Limited | Real estate | 2025 |
| Mill Strand Developments Ltd. | Construction | 1998 |
| Millenium Wood Products Limited | Wholesale & retail | 2021 |
| Millstrand Limited | Professional & scientific | 2003 |
| Millstrand Properties Limited | Construction | 2005 |
| Milo Wheels Ltd | Administrative & support | 2019 |
| Mindset, Muscle & Mortgages Limited | Financial services | 2023 |
| Mini Worxx UK Ltd | Wholesale & retail | 2024 |
| Misobar Ltd | Hospitality | 2024 |
| Mitec Solutions Ltd | Professional & scientific | 2018 |
| Mitton Manor Primary Academy | Education | 2013 |
| Mitton Way Flats (Tewkesbury) Limited | Households | 1976 |
| Mj's Gym Ltd | Arts & recreation | 2021 |
| Mjbk Land Ltd | Real estate | 2021 |
| MJD Dining Ltd | Hospitality | 2025 |
| MJF Electrical Limited | Construction | 2016 |
| MJF Investment Properties Limited | Real estate | 2020 |
| MJT Farms Holdings Ltd | Financial services | 2026 |
| MJT Property Leasing Limited | Real estate | 2025 |
| MKM Buildco Ltd | Construction | 2025 |
| MKM Estates Holdings Ltd | Real estate | 2026 |
| MKM Residential Lettings Ltd | Real estate | 2025 |
| MM Deli Ltd | Hospitality | 2025 |
| Mmtm Ltd | Information & communication | 2015 |
| MNG5 Ltd | Hospitality | 2021 |
| MNM Management International Ltd | Information & communication | 2025 |
| Moffat Management Company Limited | Households | 2021 |
| Mogo Design Limited | Information & communication | 2007 |
| Mojo Management Ltd | Financial services | 2014 |
| Monarch Builders Ltd | Construction | 2019 |
| Mondo Unico Limited | Other services | 2004 |
| Montego Bay Events Ltd | Hospitality | 2026 |
| Montpellier Domestic Appliances Limited | Manufacturing | 2014 |
| Montpellier Group Appliances Ltd | Financial services | 2023 |
| Moog Fernau Limited | Manufacturing | 1970 |
| Morgan 24:7 Limited | Construction | 2020 |
| Morgan Edge Limited | Real estate | 2021 |
| Morris Security Ltd | Administrative & support | 2023 |
| Morrison Charters Medical Limited | Health & social care | 2025 |
| Morus Consulting Limited | Health & social care | 2022 |
| Mosaique Properties Limited | Real estate | 2003 |
| Moseley-Druggan Properties Limited | Real estate | 2020 |
| Mostrack Limited | Wholesale & retail | 2003 |
| Motor Caravanners'Club Limited(The) | Arts & recreation | 1962 |
| Motorsport Systems Limited | Wholesale & retail | 2015 |
| Mountmorres DPR Ltd | Real estate | 2013 |
| Mountmorres Finance Ltd | Construction | 1953 |
| Mountmorres Holdings Ltd | Real estate | 2013 |
| Mountmorres Property Ltd | Real estate | 2013 |
| Mountmorres RGM II Ltd | Real estate | 2013 |
| MOUNTMORRES25 Limited | Real estate | 2026 |
| MRP UK Acquisition Co Ltd | Professional & scientific | 2022 |
| MS Roofing (Gloucestershire) Ltd | Construction | 2024 |
| MSB Plumbing & Maintenance Limited | Construction | 2021 |
| MT Landscaping and Design Ltd | Professional & scientific | 2025 |
| Mudlark Media Ltd | Professional & scientific | 2026 |
| Mustard Cake Limited | Hospitality | 2022 |
| MX2TWINS Limited | Information & communication | 2025 |
| Mythe Construction Limited | Construction | 2009 |
| Mythe Investments Limited | Real estate | 2016 |
| N X S Clearance Limited | Water & waste | 1999 |
| N.O. Cotswold Limited | Transport & logistics | 2019 |
| Nail Express Ltd | Other services | 2023 |
| Naked Gloves Ltd | Manufacturing | 2023 |
| Nakis Investments Ltd | Wholesale & retail | 2020 |
| Nali Foods Ltd | Wholesale & retail | 2025 |
| NAN Wayside Limited | Hospitality | 2023 |
| Nationwide Secure Document Archives Limited | Other services | 2021 |
| Natnick Ltd | Financial services | 2023 |
| Natton Holdings LLP | | 2023 |
| Natton House Thoroughbreds Limited | Agriculture & fishing | 2004 |
| Naturally Nordic Beauty Limited | Other services | 2011 |
| NB 54932 Ltd | Administrative & support | 2016 |
| NBL Financial Management Limited | Financial services | 2000 |
| Nbra Ltd | Professional & scientific | 2026 |
| ND Hub Northwest CIC | Administrative & support | 2025 |
| Neal Machinery Limited | Wholesale & retail | 2003 |
| Neal's Yard Remedies (Cheltenham) LLP | | 2017 |
| Nenkovbg Ltd | Transport & logistics | 2019 |
| Netomnia Limited | Information & communication | 2019 |
| New Docs Limited | Health & social care | 2010 |
| New Driver Academy Limited | Other services | 2012 |
| New Markets (Tewkesbury) Limited | Professional & scientific | 2009 |
| New View Property Limited | Real estate | 2020 |
| Newold Precision Engineering Ltd | Manufacturing | 2017 |
| Newsboost Limited | Professional & scientific | 1995 |
| Nibula Treats Ltd | Wholesale & retail | 2022 |
| Nick of Time Design LLP | | 2022 |
| Nicky Barrett Dressage Limited | Professional & scientific | 2010 |
| Nigel G Murphy Limited | Administrative & support | 2012 |
| NJW Payroll Solutions Limited | Professional & scientific | 2015 |
| Noble Green Holdings Ltd | Financial services | 2026 |