| Mbros Construction Ltd | Construction | 2018 |
| MBT Property Management Ltd | Hospitality | 2021 |
| MC & LS Transport Limited | Transport & logistics | 2017 |
| MC Construction (Kent) Limited | Construction | 2022 |
| MC Geoconsulting Ltd | Professional & scientific | 2026 |
| MC Roberts Plumbing & Heating (Kent) Ltd | Construction | 2026 |
| MC Travel Ltd | Transport & logistics | 2025 |
| MC Truck & BUS Limited | Wholesale & retail | 1976 |
| Mcaengineering Services Ltd | Professional & scientific | 2020 |
| Mcarthur Park Estate Management Company Limited | Households | 2005 |
| Mcauley Estates Ltd | Real estate | 2026 |
| MCB Electrical & Design Ltd | Construction | 2022 |
| Mccann International Ltd | Wholesale & retail | 2005 |
| Mccrail Ltd | Construction | 2016 |
| MCE Holdings Limited | Financial services | 2005 |
| MCE Insurance Limited | Financial services | 1975 |
| MCE Logistics Limited | Transport & logistics | 2019 |
| Mckean Brown Education Associates Ltd | Education | 2016 |
| Mckenna Property Management Limited | Real estate | 2020 |
| Mckenzie Plastering & Decorating Service Ltd | Construction | 2023 |
| Mcmedia UK Limited | Professional & scientific | 2009 |
| Mcpherson Steel Ltd | Manufacturing | 2018 |
| MCS Lettings Limited | Real estate | 2015 |
| MCS Solar Ltd. | Construction | 2024 |
| MD Dales Ltd | Administrative & support | 2018 |
| MD Fire Safety Limited | Public administration | 2019 |
| MD Kent Limited | Hospitality | 2016 |
| MD Transport Consultancy Services Ltd | Transport & logistics | 2026 |
| MD9J Enterprises Ltd | Wholesale & retail | 2026 |
| MDB Recruitment Ltd | Administrative & support | 2025 |
| MDM Software Development Limited | Information & communication | 2017 |
| Mdst Catering Ltd | Hospitality | 2026 |
| ME Card Ltd | Wholesale & retail | 2024 |
| ME Catering Limited | Hospitality | 2026 |
| ME16 Jade House Limited | Hospitality | 2024 |
| Meades Security Limited | Administrative & support | 2017 |
| Meadowbank Court Limited | Households | 1999 |
| Meander Films Ltd | Information & communication | 2026 |
| MEB Media Limited | Information & communication | 2009 |
| MEB Media Publishing Limited | Professional & scientific | 2015 |
| Mecaj Property Management Ltd | Real estate | 2024 |
| Mech Pump Ltd | Professional & scientific | 2019 |
| Mechy Native Kitchen and Bar Ltd | Hospitality | 2022 |
| Mecs (Electrical Contractors) Ltd | Construction | 2014 |
| Med-H Care Limited | Health & social care | 2023 |
| Medalia Limited | Wholesale & retail | 1995 |
| Medcraft Enterprises Limited | Hospitality | 2002 |
| Meddestane Property LLP | | 2016 |
| Medevent Medical Services Ltd | Health & social care | 2011 |
| Medi-Call Limited | Health & social care | 2025 |
| Media Byte Limited | Information & communication | 2009 |
| Media Medical Ltd | Health & social care | 2022 |
| Media Shed Limited | Professional & scientific | 2008 |
| MEDIC8 Consultancy Limited | Health & social care | 2025 |
| Medical Warehouse (Africa) Ltd | Wholesale & retail | 2020 |
| Medical Warehouse (UK) Limited | Extraterritorial | 2009 |
| Medicine Tree Ltd | Health & social care | 2012 |
| Medicom Group Limited | Professional & scientific | 2003 |
| Medicys International Limited | Professional & scientific | 2026 |
| Medicys Limited | Professional & scientific | 2002 |
| Medidgderm Limited | Health & social care | 2025 |
| Mediterranean Selman Ltd | Hospitality | 2024 |
| Medspal Ltd | Professional & scientific | 2023 |
| Medway (NO.1) Management Company Limited | Households | 2004 |
| Medway Civils & Utilities Ltd | Construction | 2010 |
| Medway Insulations Limited | Construction | 1955 |
| Medway Integrated Engineering Services Limited | Construction | 2019 |
| Medway Motorcycle Training Limited | Education | 2020 |
| Medway Pest Management Ltd | Administrative & support | 2025 |
| Medway Tours Ltd | Administrative & support | 2020 |
| Meet ME (UK) Limited | Hospitality | 2014 |
| Mefeot Limited | Extraterritorial | 2025 |
| Mega Engineers Ltd | Professional & scientific | 2013 |
| Megabite Coffee Shop Ltd | Hospitality | 2013 |
| Megahertz Electrical Ltd | Construction | 2018 |
| Megahertz Properties Ltd | Real estate | 2023 |
| Megamask Ltd | Information & communication | 2020 |
| Megk Limited | Other services | 2017 |
| Mehana Ltd | Hospitality | 2025 |
| Melad Trading Ltd | Hospitality | 2024 |
| Melita Consulting Limited | Information & communication | 2020 |
| Melna Piektdiena Ltd | Wholesale & retail | 2024 |
| Mema Group 78 Ltd | Real estate | 2025 |
| Memories and Miles Ltd | Manufacturing | 2026 |
| Mentone Property Limited | Real estate | 2016 |
| Mentorvill Ltd | Information & communication | 2020 |
| Mepa Academy Limited | Education | 2021 |
| MER Pack Production Limited | Manufacturing | 2024 |
| Mercari Trading Ltd | Wholesale & retail | 2025 |
| Mercator Road Markings Ltd | Construction | 2021 |
| Mercenary Ltd | Transport & logistics | 2025 |
| Mercer AV Limited | Construction | 2012 |
| Mercer Electrical (South East) Ltd | Construction | 2020 |
| Merchant Support UK Limited | Wholesale & retail | 2008 |
| MERCI-4TEM Services Limited | Administrative & support | 2022 |
| Mercury Autocare Limited | Wholesale & retail | 2013 |
| Mercy Logistics | Transport & logistics | 2009 |
| Mereworth Wines Limited | Manufacturing | 2016 |
| Meridian Capital Development Limited | Real estate | 2026 |
| Meridian Managed Services Ltd | Information & communication | 2018 |