| ME Care Group Dystlegh Ltd | Financial services | 2026 |
| ME Care Group II Ltd | Financial services | 2023 |
| ME Care Group Ltd | Financial services | 2022 |
| ME10 Developments Limited | Construction | 2024 |
| ME10 Investments Limited | Real estate | 2025 |
| Meades Consulting LLP | | 2008 |
| Meades Contractors Limited | Professional & scientific | 2014 |
| Meades Group Holdings Limited | Real estate | 2017 |
| Meades Group Limited | Professional & scientific | 2016 |
| Meades Wealth Management Limited | Financial services | 2021 |
| Meadow Gate (2) Management Limited | Households | 2010 |
| Meadow Hill Investments Ltd | Real estate | 2020 |
| Meadow House (Streatham) Management Company Limited | Households | 2025 |
| Meadow Rose Enterprise Ltd | Real estate | 2022 |
| Meadow Square Management Co. Limited | Real estate | 1984 |
| Meadowvale Limited | Real estate | 1949 |
| Meander Travel Limited | Administrative & support | 1980 |
| Measure & FIX AI Ltd | Information & communication | 2026 |
| Measure Health Ltd | Health & social care | 2019 |
| Measureworx Limited | Professional & scientific | 2023 |
| Meat Beast Limited | Hospitality | 2025 |
| Mecha Operation Ltd | Manufacturing | 2022 |
| Mecmed Medical Limited | Manufacturing | 2025 |
| Medalpark Limited | Hospitality | 1984 |
| Medeea&David Transport Ltd | Transport & logistics | 2024 |
| Medi Wholesale Limited | Wholesale & retail | 2020 |
| Media Distribution Group Limited | Transport & logistics | 2022 |
| Media Health Limited | Health & social care | 2018 |
| Media Place Limited | Wholesale & retail | 2022 |
| Media Storehouse Limited | Wholesale & retail | 2002 |
| Medic on SET Limited | Health & social care | 2025 |
| MEDIC8 Health Group Ltd | Wholesale & retail | 2020 |
| Medical Locum Recruitment Limited | Administrative & support | 2017 |
| Medical Service Providers Limited | Administrative & support | 2015 |
| Medicloflex Ltd | Health & social care | 2026 |
| Medicom Solutions Ltd | Professional & scientific | 2019 |
| Medilogistics Limited | Transport & logistics | 2005 |
| Medimedu Ltd | Professional & scientific | 2025 |
| Medina Food Store & Halal Meat Ltd | Wholesale & retail | 2012 |
| Medina Lodge Residents Association Limited | Real estate | 1997 |
| Medinsight Ltd | Education | 2024 |
| Medivet Acquisitions Limited | Professional & scientific | 2006 |
| Medivet Group Holdings Limited | Professional & scientific | 2019 |
| Medivet Group Limited | Professional & scientific | 1997 |
| Medivet Partnership LLP | | 2009 |
| Medlink Solutions Ltd | Information & communication | 2019 |
| Medtronic Limited | Manufacturing | 1972 |
| Medtrum Ltd | Manufacturing | 2016 |
| Medullon Limited | Administrative & support | 2024 |
| Medway Parade (Western Block) Residents' Association Limited | Households | 1993 |
| Meeb Management Limited | Households | 1996 |
| Meeten Nathwani Limited | Real estate | 2010 |
| Meezbaan Limited | Wholesale & retail | 2024 |
| Mega Ltd | Information & communication | 2009 |
| Meganelizabeth Ltd | Hospitality | 2025 |
| Megatastic Gifts Ltd | Wholesale & retail | 2021 |
| Megatrend Capital Partners Ltd | Financial services | 2015 |
| Meggetland Consulting Ltd | Administrative & support | 2024 |
| MEH Capital Limited | Information & communication | 2011 |
| Mehkrish Ltd | Transport & logistics | 2026 |
| Mehlo Investments Ltd | Financial services | 2021 |
| Mehyar Salem LO Presti Limited | Health & social care | 2018 |
| Meiya Global Ltd | Wholesale & retail | 2026 |
| MEK Windows Ltd | Construction | 2025 |
| Mekkah Food Store Ltd | Wholesale & retail | 2024 |
| MEL Mcgowan Limited | Construction | 2007 |
| Mela Paul Limited | Professional & scientific | 2019 |
| Meliore Ltd | Professional & scientific | 2012 |
| Mellon ETM Company Limited | Education | 2020 |
| Melo Bakery Ltd | Manufacturing | 2020 |
| Melo the Bakery Company Ltd | Real estate | 2020 |
| Melrose Property Investments Ltd | Real estate | 2017 |
| Melto Ltd | Hospitality | 2025 |
| Membership Administration Services Limited | Other services | 2013 |
| Memorials and Rock Produce UK Limited | Manufacturing | 2014 |
| Mend Men's Mental Health CIC | Public administration | 2024 |
| Mendel Strata Ltd | Wholesale & retail | 2024 |
| Mendels Limited | Manufacturing | 2013 |
| Mendisign Limited | Professional & scientific | 2021 |
| Mendora Wellness Limited | Wholesale & retail | 2025 |
| Meniya Ltd | Information & communication | 2023 |
| Meniyo Ltd | Wholesale & retail | 2024 |
| Mensahm Ltd | Professional & scientific | 2023 |
| Menspire Watford Limited | Other services | 2019 |
| Merali Digital Limited | Administrative & support | 2010 |
| Mercado Luso Brasil Ltd | Wholesale & retail | 2021 |
| Mercantile Consulting Ltd | Professional & scientific | 2015 |
| Merchant Construction Limited | Construction | 2025 |
| Merchant Venture Ltd | Wholesale & retail | 2006 |
| Mercury Academic Ltd | Information & communication | 2024 |
| Mercury Contractors Project Ltd | Construction | 2021 |
| Mercury One Services Limited | Wholesale & retail | 2007 |
| Merge Information and Systems Limited | Information & communication | 1997 |
| Meriden Service Centre Limited | Wholesale & retail | 2015 |
| Meridian Trade and Customs Ltd | Administrative & support | 2026 |
| Merito Corporation Ltd | Wholesale & retail | 2023 |
| Merq Global Software Services Limited | Information & communication | 2018 |
| Merritt Ltd | Professional & scientific | 2017 |
| Merry Hill Development (Holdings) Limited | Financial services | 2019 |
| Merry Hill Development Limited | Construction | 2018 |