| Meadow Lane Developments Limited | Real estate | 2005 |
| Meadow Lane Investment Company Limited | Real estate | 2008 |
| Meadow LET Group Ltd | Construction | 2023 |
| Meadow Mist Properties Ltd | Real estate | 2026 |
| Meadow View Caravan Park Limited | Hospitality | 2026 |
| Mean & Clean Recovery CIC | Health & social care | 2025 |
| Mean&Clean Ltd | Health & social care | 2024 |
| Meander Design Limited | Information & communication | 2015 |
| Mecam Merkelbach Capital Management Limited | Administrative & support | 2006 |
| Mechpipe Designs Ltd | Administrative & support | 2021 |
| MED Bars 2022 Ltd | Hospitality | 2022 |
| MED Kitchens Limited | Construction | 2003 |
| MED2B Ltd. | Manufacturing | 2012 |
| MED80 Limited | Health & social care | 2019 |
| Medbasic Ltd | Wholesale & retail | 2022 |
| Mediahubink Limited | Professional & scientific | 2026 |
| Mediapool International | Professional & scientific | 2017 |
| Medical Legal Limited | Administrative & support | 2008 |
| Medicol Limited | Manufacturing | 1988 |
| Medics & Linguistics Nationwide Ltd | Administrative & support | 2014 |
| Medicus Services Limited | Health & social care | 2018 |
| Medley Outlet 786 Ltd | Wholesale & retail | 2018 |
| Medoria Limited | Energy | 2005 |
| Medplus Health Limited | Health & social care | 2024 |
| Megasus Limited | Administrative & support | 2004 |
| Meghna Restaurant Ltd | Hospitality | 2024 |
| Megsmethodcoaching Ltd | Arts & recreation | 2026 |
| Meikles Fraud and Forensic Examiners Limited | Professional & scientific | 2022 |
| Meisterbetrieb Machold Ltd | Administrative & support | 2006 |
| Mel's Property Solutions Limited | Real estate | 2024 |
| Melia Property Investments Limited | Real estate | 2022 |
| Melissa Wilcock Limited | Financial services | 2021 |
| Melksham Development Company Ltd | Construction | 2018 |
| Mellow Coaching & Consultancy Ltd | Health & social care | 2025 |
| Melmaison Ltd | Real estate | 2021 |
| Mendzco Ltd | Information & communication | 2025 |
| Mentorbird (UK) Limited | Professional & scientific | 2015 |
| MER Elite Ltd | Construction | 2025 |
| Merabiz Limited | Administrative & support | 2014 |
| Meraki Artisan Baker Ltd | Manufacturing | 2026 |
| Mercedes Martinez | Administrative & support | 2015 |
| Mercer EP and Cardiology Limited | Health & social care | 2022 |
| Merchants Granary Ltd | Real estate | 2014 |
| Meridian Products and Services Limited | Manufacturing | 2026 |
| Merlins Wakefield Limited | Arts & recreation | 2017 |
| Mermaid Fish Restaurant Limited | Hospitality | 1976 |
| Merriecity Solutions Limited | Professional & scientific | 2013 |
| Mersey NW Ltd | Hospitality | 2023 |
| Mersey Waterfront Ltd | Extraterritorial | 2024 |
| Mertens Engineering Ltd. | Construction | 2005 |
| Meshi Property Development Ltd | Construction | 2022 |
| Message Wizard Limited | Information & communication | 2025 |
| Met-Sec Limited | Administrative & support | 2020 |
| METAB3E London & South East Limited | Administrative & support | 2006 |
| METAB3E Ltd | Administrative & support | 2018 |
| Metcalf Landscapes (Yorkshire) Ltd. | Administrative & support | 2018 |
| Metcalfe Farming Limited | Agriculture & fishing | 2009 |
| Metermate Ltd | Construction | 2025 |
| Metro Munch Ltd | Hospitality | 2025 |
| Metro Yorkshire Ltd | Wholesale & retail | 2025 |
| Metropolitan Agency Limited | Administrative & support | 2013 |
| Metropolitan Demolition Ltd | Construction | 2015 |
| Metta Connect Ltd | Professional & scientific | 2021 |
| Mexicali Express Ltd | Hospitality | 2025 |
| Meyer Bausanierung Ltd | Construction | 2025 |
| Mforeve Ltd | Health & social care | 2019 |
| MG Evans (Properties) Limited | Real estate | 2005 |
| Mglead Bars Ltd | Hospitality | 2025 |
| MH Accounting Services Limited | Professional & scientific | 2012 |
| MH Design & Artwork Limited | Professional & scientific | 2007 |
| MH Prime Properties Limited | Households | 2025 |
| MH WKD Limited | Hospitality | 2025 |
| MHA Properties & Lettings Ltd | Real estate | 2026 |
| MHC Autos Ltd | Wholesale & retail | 2025 |
| MHH Cars and Commercials Ltd | Wholesale & retail | 2025 |
| MHL Investments Ltd | Real estate | 2025 |
| MHL OPS Limited | Financial services | 2019 |
| MHN Cleaning Solutions Ltd | Administrative & support | 2023 |
| MHS Health Care Ltd | Health & social care | 2010 |
| MHS Publishers Ltd | Information & communication | 2021 |
| Mhtravel Ltd | Transport & logistics | 2024 |
| Michael D Joyce Associates LLP | | 2002 |
| Michael New Limited | Wholesale & retail | 2019 |
| Michael Oliver Financial Consulting Ltd | Financial services | 2015 |
| Michelle Nash Medical Aesthetics Ltd | Health & social care | 2026 |
| Mick Sargent Building Services Ltd | Construction | 2024 |
| Micra Holdings Limited | Financial services | 2002 |
| Micra Truck Bodies Limited | Manufacturing | 2000 |
| Microform Imaging Limited | Professional & scientific | 1988 |
| Midas Barber & Supply Ltd | Other services | 2018 |
| Midas Golf Limited | Extraterritorial | 2002 |
| Middlestown Carpets and Furniture Limited | Wholesale & retail | 1979 |
| Middlestown Enterprises Limited | Wholesale & retail | 2008 |
| Middlestown Properties Limited | Real estate | 2017 |
| Middlestown Restaurants Ltd | Hospitality | 2024 |
| Midgley Locum Ltd | Professional & scientific | 2018 |
| Midsett RMO Ltd | Health & social care | 2014 |
| MIE Enterprise Ltd | Information & communication | 2024 |
| Mighty Oaks Theatre Company CIC | Arts & recreation | 2024 |
| Migraine Angels Ltd | Health & social care | 2014 |