| Meadowcourt Holdings Limited | Financial services | 2020 |
| Meadowcourt Investments Limited | Real estate | 2025 |
| Meadows Healthcare Limited | Health & social care | 2013 |
| Meadows Sports Association Limited | Other services | 2004 |
| Meadowtown Trusted Ltd | Construction | 2014 |
| Meadway Developments & Lettings Ltd | Real estate | 2016 |
| Meaks Limited | Real estate | 2022 |
| Meal Prep Mama Ltd | Hospitality | 2021 |
| Mealey Electrical Contractors Limited | Construction | 2008 |
| Mealey Group Limited | Professional & scientific | 2017 |
| Mealey Projects Limited | Construction | 2017 |
| Mean Green Burgers Ltd | Hospitality | 2022 |
| Meap Properties Ltd | Real estate | 2026 |
| Measham Holding Ltd | Health & social care | 2026 |
| Measom (Dryline) Limited | Construction | 1969 |
| Measom Building Finishes Limited | Professional & scientific | 2024 |
| Measom Design Limited | Professional & scientific | 2011 |
| Measom Dryline (South West) Limited | Construction | 2018 |
| Measom Dryline (South) Limited | Extraterritorial | 2022 |
| Measom Drywall Limited | Extraterritorial | 2022 |
| Measom Fire Protection Limited | Construction | 1994 |
| Measom Holdings Limited | Construction | 2013 |
| Meat Farm Ltd | Wholesale & retail | 2024 |
| Meat Media Ltd | Professional & scientific | 2018 |
| MEC Construction Ltd | Construction | 2020 |
| Mech (Building) Services Ltd | Construction | 2008 |
| Mech (Electrical) Services Limited | Construction | 2016 |
| Mech Lube Limited | Wholesale & retail | 2025 |
| Mech Selected Services Limited | Construction | 2013 |
| Mechanics Limited | Construction | 2003 |
| Mechasoft Limited | Information & communication | 1999 |
| Meckow Limited | Wholesale & retail | 2003 |
| Mectech-Aviation Ltd | Administrative & support | 2025 |
| Mectric Limited | Construction | 2007 |
| MED Aesthetics Inc Limited | Other services | 2012 |
| MED Brothers Ltd | Wholesale & retail | 2023 |
| MED Chambers Limited | Professional & scientific | 2009 |
| MED Innovate Healthcare Ltd | Health & social care | 2025 |
| Medals Enterprises Ltd | Real estate | 2021 |
| Medarchis Ltd | Information & communication | 2025 |
| Medbourne Group LLP | | 2025 |
| Medbourne Limited | Hospitality | 2005 |
| Medburn Transport Ltd | Transport & logistics | 2014 |
| Medcare International Ltd | Administrative & support | 2024 |
| Medchemtronica UK Ltd | Wholesale & retail | 2025 |
| Medcore Solutions Ltd | Health & social care | 2024 |
| Meddea Ltd | Arts & recreation | 2008 |
| Meddiquest Limited | Professional & scientific | 2001 |
| Medescon Limited | Wholesale & retail | 2015 |
| Medex Pharmaceuticals Ltd | Wholesale & retail | 2020 |
| Medeye Estates Ltd | Health & social care | 2024 |
| Medgidia Limited | Hospitality | 2021 |
| Medhurst 1953 Limited | Extraterritorial | 2013 |
| Media 13 Limited | Professional & scientific | 2016 |
| Media Active Ltd | Wholesale & retail | 2019 |
| Media B Limited | Professional & scientific | 2014 |
| Media Entertainment UK Ltd | Administrative & support | 2025 |
| Media Halo Ltd | Extraterritorial | 2021 |
| Media Kouture Studios Ltd | Professional & scientific | 2025 |
| Media Magic Ltd | Information & communication | 2003 |
| Media Remedy Limited | Wholesale & retail | 2010 |
| Media Walls Leicester Ltd | Other services | 2020 |
| Mediaola Limited | Extraterritorial | 2008 |
| Mediation Matters Midlands Limited | Other services | 2018 |
| Medical Corps UK Ltd | Health & social care | 2018 |
| Medical Health Hub Ltd | Health & social care | 2021 |
| Medical Made Easy Limited | Financial services | 2017 |
| Medical Physician Ltd | Health & social care | 2021 |
| Medical Reports (Midlands) Limited | Health & social care | 2011 |
| Medical Specialist Healthcare Ltd | Health & social care | 2025 |
| Medicanova Limited | Health & social care | 2024 |
| Medicardio Limited | Health & social care | 2023 |
| Medicare Pharmacy Limited | Health & social care | 1992 |
| Medicinacare Ltd | Real estate | 2019 |
| Medicine Chest Healthcare Limited | Wholesale & retail | 2021 |
| Medicine Chest Pharmacy Limited | Wholesale & retail | 1999 |
| Medicine Direct Ltd | Administrative & support | 2021 |
| Medicines Management Solutions Ltd | Health & social care | 2007 |
| MEDICINES2U.COM Limited | Extraterritorial | 2008 |
| Medico Locum Cover Limited | Health & social care | 2018 |
| Medicom Distribution Limited | Wholesale & retail | 2024 |
| Medicomp UK Limited | Wholesale & retail | 2022 |
| Medics ABD Ltd | Health & social care | 2024 |
| Medicure Pharmacy Limited | Wholesale & retail | 2000 |
| Medigravitas Ltd | Health & social care | 2023 |
| Medigrid Tech Ltd | Information & communication | 2024 |
| Mediluma Limited | Health & social care | 2025 |
| Medina Retail Ltd | Wholesale & retail | 2024 |
| Medique Healthcare Limited | Extraterritorial | 2015 |
| Medisurge UK Ltd | Wholesale & retail | 2020 |
| MEDITATION4ALL C.I.C. | Information & communication | 2023 |
| Meditech Clinical Consultancy Ltd | Health & social care | 2013 |
| Medium Limited | Professional & scientific | 2014 |
| Medlife Consultancy Ltd | Health & social care | 2022 |
| Medls Limited | Real estate | 2001 |
| Medpro Essentials Ltd | Wholesale & retail | 2025 |
| Medsafe Medicals Limited | Health & social care | 2018 |
| Medscitech Communications Ltd | Extraterritorial | 2015 |
| Medsio Healthcare Private Limited | Wholesale & retail | 2025 |
| Medspruce Ltd | Health & social care | 2009 |