| Melville Barrow Limited | Professional & scientific | 2018 |
| Member-Flow Ltd | Professional & scientific | 2024 |
| Meme Holdings Limited | Professional & scientific | 2004 |
| Meme Media Limited | Administrative & support | 2003 |
| Memil Ltd | Real estate | 2025 |
| Memo's Kitchen Ltd | Hospitality | 2025 |
| Memo's Properties Ltd | Real estate | 2026 |
| Memorable Limited | Other services | 2017 |
| Memorable Ninja Ltd | Information & communication | 2023 |
| Memori Property Investments Ltd | Real estate | 2024 |
| Memorial Window Trading Limited | Professional & scientific | 2019 |
| Memories From Before Ltd | Information & communication | 2018 |
| Memories of Seoul Ltd | Wholesale & retail | 2022 |
| Memoryboxfilms Limited | Information & communication | 2022 |
| Memos Bar 149 Ltd | Hospitality | 2026 |
| Memos Food Ltd | Hospitality | 2025 |
| MEN and Women's Pactmantality CIC | Health & social care | 2022 |
| MEN United Against Suicide CIC | Health & social care | 2023 |
| Mena Estates Ltd | Real estate | 2019 |
| Menai View Cottages Ltd | Hospitality | 2022 |
| Mencap Liverpool | Administrative & support | 1987 |
| Mend Consulting Ltd | Health & social care | 2019 |
| Menel Cleaning Services Ltd | Administrative & support | 2024 |
| Menelaus Properties Limited | Real estate | 2022 |
| Meng's Kitchen Ltd | Hospitality | 2025 |
| Menlove Car Centre Ltd | Wholesale & retail | 2017 |
| Menmatter Organisation Ltd | Health & social care | 2019 |
| Meno II Ltd | Health & social care | 2025 |
| Menon Mind Ltd | Health & social care | 2025 |
| Mens Accommodation and Support | Administrative & support | 2009 |
| Mental Core Training Ltd | Health & social care | 2025 |
| Mentalis Diagnostics Global Ltd | Professional & scientific | 2025 |
| Mentes Properties Limited | Real estate | 2015 |
| Menzies CI Services Ltd | Professional & scientific | 2023 |
| Menzies Mcginnes Properties Ltd | Households | 2025 |
| Men’S Wellbeing Network CIC | Education | 2026 |
| MEO Marine Contractors Limited | Construction | 2025 |
| Meog Ltd | Hospitality | 2025 |
| MEP Compliance Ltd | Professional & scientific | 2026 |
| Meranti Property Group Ltd | Real estate | 2023 |
| Mercanixxx Ltd | Wholesale & retail | 2023 |
| Mercat Properties Ltd | Real estate | 2001 |
| Mercer Consultancy Ltd | Other services | 2017 |
| Mercer Panel Systems Limited | Construction | 2007 |
| Merchant Court (Crosby) Limited | Real estate | 2021 |
| Merchant Taylors' Schools Crosby Services Limited | Real estate | 2013 |
| Merchstar Limited | Wholesale & retail | 2024 |
| Merco Developments Limited | Construction | 2014 |
| Merco Maintenance Ltd | Construction | 2017 |
| Mercon IT Limited | Information & communication | 2017 |
| Mercury Alarm Services Limited | Administrative & support | 1979 |
| Mercury Commodities Limited | Wholesale & retail | 2004 |
| Mercury Estates (ST Helens) Ltd | Real estate | 2020 |
| Mercy Management Limited | Professional & scientific | 2016 |
| Mercy One Ltd | Other services | 2026 |
| Mercyjude Properties Limited Limited | Real estate | 2024 |
| Mere Hall Farm Limited | Financial services | 2019 |
| Mere Lane Developments Limited | Construction | 2020 |
| Merebridge Holdings Ltd | Financial services | 2026 |
| Merebridge Management Ltd | Real estate | 2025 |
| Mereway Kitchens Limited | Manufacturing | 1986 |
| Merge Property Solutions Ltd | Real estate | 2024 |
| Merid Ltd | Wholesale & retail | 2025 |
| Meridian Place Freehold Limited | Households | 2012 |
| Meridian Publications Limited | Information & communication | 1998 |
| Meridians Properties UK Limited | Real estate | 2024 |
| Merino Medics Limited | Health & social care | 2016 |
| Merino Web Services Ltd | Information & communication | 2018 |
| Meritis Management Ltd | Wholesale & retail | 2021 |
| Merlewood Management Company Limited | Administrative & support | 1993 |
| Merlin Courier Services Limited | Transport & logistics | 2021 |
| Merlin Decor Ltd | Construction | 2025 |
| Merridian Technical Support Services Limited | Professional & scientific | 2025 |
| Merrilocks Management Limited | Households | 2002 |
| Merrilocks Road (DB) Ltd | Households | 2025 |
| Merrion Strategy Limited | Wholesale & retail | 2012 |
| Merrymile Estates Ltd | Real estate | 2001 |
| Mersea Farming Ltd | Agriculture & fishing | 2025 |
| Mersea Sauna Ltd | Other services | 2023 |
| Merselec Ltd | Construction | 2021 |
| Mersey & Co Brands Ltd | Manufacturing | 2025 |
| Mersey Accountants Ltd | Professional & scientific | 2019 |
| Mersey Anaesthesia and Critical Care Services Limited | Health & social care | 2024 |
| Mersey and Metropolitan Investment Company Limited | Construction | 1980 |
| Mersey Auto Repair and Travel Ltd | Wholesale & retail | 2026 |
| Mersey Auto Sales Limited | Wholesale & retail | 2025 |
| Mersey Blue Investments Ltd | Financial services | 2024 |
| Mersey Brew Ltd | Hospitality | 2025 |
| Mersey Brickwork Limited | Construction | 2016 |
| Mersey Care Bridge Ltd | Administrative & support | 2026 |
| Mersey Care Homes Ltd | Health & social care | 2021 |
| Mersey Cargo Limited | Transport & logistics | 2025 |
| Mersey Chambers Limited | Real estate | 2016 |
| Mersey Cleaning Ltd | Other services | 2024 |
| Mersey Concrete Limited | Manufacturing | 2010 |
| Mersey Consulting Ltd | Professional & scientific | 2025 |
| Mersey Cool Ltd | Construction | 2025 |
| Mersey Design Group Limited | Professional & scientific | 1993 |
| Mersey Design Limited | Professional & scientific | 2005 |
| Mersey Development & Construction Ltd | Construction | 2025 |