| Mclean Lettings Ltd | Hospitality | 2020 |
| Mcmanus Electrics Ltd | Extraterritorial | 2016 |
| Mcmurdo Land Planning and Development Limited | Professional & scientific | 2017 |
| Mcqueenie Mulholland Ltd | Professional & scientific | 2022 |
| MCR Approved Cars Limited | Wholesale & retail | 2025 |
| MCS Property Limited | Real estate | 2007 |
| MD Audio Solutions Limited | Wholesale & retail | 2012 |
| Mdbi South West Ltd | Construction | 2023 |
| MDM Garages Ltd | Wholesale & retail | 2023 |
| ME the Leader Ltd | Education | 2014 |
| Meadfoot Grange Management Company Limited | Households | 2001 |
| Mealpal Limited | Hospitality | 2016 |
| Mears Investments Ltd | Real estate | 2018 |
| MEAT59 Limited | Hospitality | 2015 |
| Meating House Ltd | Hospitality | 2022 |
| MEC Facilities Limited | Manufacturing | 2016 |
| Mechelec Solutions Limited | Professional & scientific | 2012 |
| Meddah Tyres Ltd | Other services | 2019 |
| Medent Ltd | Real estate | 2021 |
| Medgehog & Monkey Limited | Real estate | 2022 |
| Media Developments (Nailsea) Limited | Real estate | 2020 |
| Media Developments Ltd | Real estate | 2020 |
| Media Leads Ltd | Administrative & support | 2017 |
| Media Searches Limited | Administrative & support | 2019 |
| Media Street Limited | Information & communication | 2009 |
| Mediaconcepts Hospitality Solutions Limited | Information & communication | 2016 |
| Mediation First Limited | Professional & scientific | 2022 |
| Medicaflex Ltd | Health & social care | 2025 |
| Medical & Education Consulting Limited | Health & social care | 2018 |
| Medical Negligence Lawyers Limited | Professional & scientific | 2014 |
| MEDICALS4U Limited | Health & social care | 2006 |
| Medicines Data Consultancy Limited | Information & communication | 2018 |
| Medifesto Ltd | Professional & scientific | 2022 |
| Medipro Transport Ltd | Transport & logistics | 2026 |
| Meditation Mamma Ltd | Wholesale & retail | 2025 |
| Medivoice Recruit Ltd | Health & social care | 2020 |
| Medland Manor Vineyard Ltd. | Manufacturing | 2018 |
| Medmap Ltd | Information & communication | 2024 |
| Medora Road Limited | Real estate | 2020 |
| Meetmip Limited | Other services | 2014 |
| Meftah Holdings Ltd | Financial services | 2023 |
| Megadum Construct Ltd | Construction | 2020 |
| Meguke Partners Ltd | Other services | 2022 |
| Mekion Consulting Limited | Professional & scientific | 2025 |
| Melcaxini UK Limited | Wholesale & retail | 2024 |
| Melcroft Management Limited | Hospitality | 1987 |
| Meldon Viaduct Company Limited | Arts & recreation | 1998 |
| Melita Care Limited | Health & social care | 2005 |
| Melita Holdings Limited | Financial services | 2022 |
| Melo Group Ltd | Hospitality | 2023 |
| Melo Ventures Ltd | Wholesale & retail | 2023 |
| Melona Properties Limited | Real estate | 2016 |
| Melzo Limited | Wholesale & retail | 2018 |
| Menoeceus Limited | Financial services | 2018 |
| Mentem Publishing Ltd | Information & communication | 2008 |
| Merakai Spaces Ltd | Construction | 2024 |
| Meraki Art School Limited | Education | 2023 |
| Meraki Lifestyle Limited | Other services | 2013 |
| Merchandising & Supply Transformation Limited | Professional & scientific | 2025 |
| Merchant Properties and Lettings Limited | Real estate | 2024 |
| Mercury Forklift Services Limited | Professional & scientific | 2011 |
| Meridian Commerce Ltd | Wholesale & retail | 2019 |
| Meritex EG Limited | Transport & logistics | 2014 |
| Meritex Holdings Worldwide Limited | Financial services | 2016 |
| Meritex International Freight Services Limited | Transport & logistics | 1998 |
| Meritex Projects Limited | Administrative & support | 2011 |
| Merlin Accountancy Services Ltd | Professional & scientific | 2005 |
| Merlin Equipment Limited | Wholesale & retail | 2000 |
| Merlin Healthcare Limited | Wholesale & retail | 2024 |
| Merlins Flooring Contractors Limited | Construction | 1991 |
| Mermaid Media Limited | Professional & scientific | 2020 |
| Mermaides Plaice Limited | Hospitality | 2026 |
| Merredew Properties Ltd | Real estate | 2018 |
| Merrick Holdings Ltd | Professional & scientific | 2025 |
| Merston Solar Farm Limited | Energy | 2013 |
| Merto (SW) Ltd | Hospitality | 2024 |
| Mesita Catering Ltd | Hospitality | 2025 |
| Mesita Deli Ltd | Wholesale & retail | 2025 |
| Mesklin Ltd | Information & communication | 2014 |
| Metalwork Solutions Limited | Manufacturing | 2004 |
| Metapower Limited | Information & communication | 2016 |
| Meticuloptics Ltd | Health & social care | 2024 |
| Metpow Ltd | Manufacturing | 2024 |
| Metrichub Ltd | Professional & scientific | 2019 |
| Metrocapital Limited | Real estate | 2014 |
| Mevacremyll Ltd | Households | 2021 |
| Mewstone Professional Services Limited | Professional & scientific | 2014 |
| Mewstone Property Investments Limited | Construction | 2017 |
| Mexpark Associates Limited | Hospitality | 2017 |
| Meyer Court RTM Company Limited | Households | 2010 |
| Meyer Leman Marks Limited | Real estate | 2014 |
| Mezeli & ALL Ltd | Professional & scientific | 2025 |
| MF Architecture Devon Ltd | Professional & scientific | 2018 |
| Mfjf (UK) Member Services Limited | Other services | 2021 |
| Mfjf (USA) Member Services Limited | Information & communication | 2020 |
| MG Agency Group Ltd | Professional & scientific | 2015 |
| MG Manco Ltd | Real estate | 2026 |
| MG Properties (SW) Ltd | Real estate | 2024 |
| MGA Consultancy Limited | Real estate | 2003 |
| MGB (Group) Limited | Professional & scientific | 2011 |