| MED Resq Ltd | Health & social care | 2018 |
| Medicine DR. Skin Research Center Ltd | Professional & scientific | 2019 |
| Medina Car Trade Limited | Wholesale & retail | 2024 |
| Medina Expedition Ltd | Transport & logistics | 2022 |
| Medserve Limited | Wholesale & retail | 1991 |
| Meliora Consultancy Services Limited | Professional & scientific | 2021 |
| Mena Plumbing Ltd | Construction | 2019 |
| Meneng Ltd | Manufacturing | 2026 |
| Mental Health Mates C.I.C. | Other services | 2019 |
| Mentivara Ltd | Manufacturing | 2026 |
| Mereacre Nicolae Ltd | Transport & logistics | 2015 |
| Merryhill Accountancy Services Limited | Professional & scientific | 2008 |
| Mesa Trans Ltd | Transport & logistics | 2018 |
| Meta Property Ltd. | Real estate | 1993 |
| Metdetech Ltd | Wholesale & retail | 2024 |
| Metokote UK Limited | Manufacturing | 1997 |
| Metryx Studios Ltd | Information & communication | 2019 |
| MEX Furniture Ltd | Wholesale & retail | 2013 |
| Meysh Ltd | Wholesale & retail | 2025 |
| Michael Christie Paving Services Ltd | Construction | 2012 |
| Midaas Trade Ltd | Wholesale & retail | 2022 |
| Midco 8787 1 Limited | Professional & scientific | 2019 |
| Midco 8787 2 Limited | Professional & scientific | 2019 |
| Midland Taxis Daventry Ltd | Transport & logistics | 2024 |
| Midlands Haven Homes Ltd | Public administration | 2024 |
| Midlands Power and Motion Ltd | Administrative & support | 2000 |
| Midwest Market Force Limited | Wholesale & retail | 1998 |
| Miiinted.Com Ltd | Information & communication | 2025 |
| MIK Consultancy Ltd | Professional & scientific | 2016 |
| Mikler Transport Ltd | Transport & logistics | 2018 |
| Milford Hall Hotel Limited | Hospitality | 2022 |
| Minascurta Ltd | Other services | 2021 |
| Mindful Holdings UK Ltd Ltd | Professional & scientific | 2026 |
| Mindscape Wellness Ltd | Health & social care | 2024 |
| Ming & Soon Limited | Hospitality | 2022 |
| Minima Technical Support Limited | Construction | 2018 |
| Mironbor Limited | Transport & logistics | 2015 |
| Mish Property Group Ltd | Real estate | 2025 |
| Mission 4D Ltd | Transport & logistics | 2018 |
| Missions Impossible Ltd | Manufacturing | 2017 |
| MJ Sieprawski Ltd | Transport & logistics | 2015 |
| MK Promotions Limited | Arts & recreation | 2002 |
| MKG Cars Ltd | Wholesale & retail | 2024 |
| Mklak Global UK Ltd | Manufacturing | 2022 |
| MM Cyber Consulting Limited | Information & communication | 2022 |
| MNA Transport Ltd | Transport & logistics | 2012 |
| Mobile FIX Ltd | Wholesale & retail | 2017 |
| Modusystems Ltd | Manufacturing | 2026 |
| Moeden Limited | Administrative & support | 2025 |
| Moirai Rooms Ltd | Other services | 2023 |
| Mojack Ltd | Financial services | 2026 |
| Mojo Food and Drink Ltd | Hospitality | 2022 |
| Molem Limited | Hospitality | 2019 |
| Monami EAT Limited | Hospitality | 2016 |
| Moovie Therapy Ltd | Wholesale & retail | 2023 |
| Morgan Dhanjal Medical Ltd | Health & social care | 2022 |
| Mortensen Consulting Ltd | Hospitality | 2022 |
| Moskay Biotechnology UK Ltd | Professional & scientific | 2020 |
| Mosto Ltd | Wholesale & retail | 2025 |
| Motiva Recruitment Group Ltd | Administrative & support | 2025 |
| Motorsport Composites Ltd | Manufacturing | 2025 |
| Motorsports Spares International Limited | Professional & scientific | 1999 |
| Mouldshop Limited | Wholesale & retail | 2001 |
| Mouldshop Properties Limited | Real estate | 2024 |
| Move IT Clear IT Ltd | Transport & logistics | 2023 |
| Mpg-Office UK Limited | Wholesale & retail | 2021 |
| MPL Tree Consultancy Ltd | Professional & scientific | 2017 |
| MR Blade Barber Ltd | Other services | 2026 |
| MRC Cleaning Solutions Ltd | Administrative & support | 2024 |
| MRH Geotechnical (Midlands) Limited | Administrative & support | 2013 |
| MT Quality Construction Limited | Construction | 2017 |
| MTM Prim Limited | Construction | 2025 |
| Mudilabs Consulting Ltd | Information & communication | 2016 |
| Mudilabs Ltd | Information & communication | 2021 |
| Muller Enterprises Limited | Wholesale & retail | 2013 |
| Munderson Co., Ltd. | Professional & scientific | 2006 |
| Muneka Catering Ltd | Hospitality | 2018 |
| Muratis Daventry Limited | Administrative & support | 2024 |
| Mushi Creative Ltd | Information & communication | 2019 |
| Muvaki Ltd | Professional & scientific | 2018 |
| MW Property & Investments Limited | Real estate | 2024 |
| My Basic Stuff Ltd | Wholesale & retail | 2022 |
| My Motor BID Online Auctions Ltd | Wholesale & retail | 2025 |
| My Time Competitions Ltd | Wholesale & retail | 2023 |
| N H Henley Ltd | Hospitality | 2026 |
| N Patel Limited | Wholesale & retail | 2022 |
| N. C. M. Equipment Limited | Administrative & support | 2006 |
| Nabida Care Limited | Health & social care | 2010 |
| NAC International Limited | | 1983 |
| Nancy's Cookhouse Ltd | Hospitality | 2023 |
| Nandan Exports & Imports Ltd | Wholesale & retail | 2020 |
| Nandan Therapeutics Ltd | Manufacturing | 2020 |
| Natavan Group Limited | Health & social care | 2020 |
| Nathaniel Dillon Ltd | Real estate | 2026 |
| Natural Stuff Limited | Wholesale & retail | 2014 |
| Naturally Light Equitation LLP | | 2020 |
| Nautilus Exhibitions Limited | Administrative & support | 2015 |
| NDA Trans Ltd | Transport & logistics | 2012 |
| NDI Automotive Ltd | Wholesale & retail | 2026 |
| NE Locum 2 Limited | Professional & scientific | 2023 |