| Lwtl Holdings Ltd | Financial services | 2026 |
| M Davies Builders (NW) Ltd | Construction | 2020 |
| M J Harrison HV Safety Solutions Limited | Professional & scientific | 2014 |
| M W R Classics Ltd | Wholesale & retail | 2017 |
| M&D Pizza Ltd | Hospitality | 2021 |
| M-Temp Ltd | Professional & scientific | 2024 |
| Mace Conwy Ltd | Construction | 2020 |
| Maclagan Limited | Real estate | 2018 |
| Maclean & Co Consulting Ltd | Professional & scientific | 2024 |
| Macs Gym Limited | Arts & recreation | 2019 |
| Mactec Security Service Ltd | Administrative & support | 2026 |
| Madeingb.Com Ltd | Information & communication | 2007 |
| Madenza Limited | Health & social care | 2015 |
| Madoc Developments Limited | Construction | 2015 |
| Maes Dolau Caravan Park (Llandudno) Limited | Hospitality | 2011 |
| Magna Property Soloution Ltd | Construction | 2022 |
| Mahdi Medical Services Ltd | Health & social care | 2025 |
| Making Tax Digital (North Wales) Limited | Professional & scientific | 2025 |
| Manderley (Hafodty Lane) Management Limited | Real estate | 2008 |
| Margetts Williams Limited | Construction | 2018 |
| Maria Mclean Marketing Limited | Professional & scientific | 2016 |
| Mark NPH Ltd | Construction | 2020 |
| Mark Water Pumps Limited | Manufacturing | 2013 |
| Marmalade Rhos on Sea Ltd | Hospitality | 2026 |
| Martin Edward Jones Ltd | Extraterritorial | 2025 |
| Mary Bamber Developments Limited | Construction | 2021 |
| MAS Construction Projects Ltd | Construction | 2018 |
| Mason Reece Jones Ltd | Extraterritorial | 2025 |
| Mates Support Group Ltd | Health & social care | 2024 |
| MAY Twelve Limited | Arts & recreation | 2024 |
| Mayalls Music Ltd. | Wholesale & retail | 2017 |
| MB Renovations NW Limited | Construction | 2021 |
| MCT Business Services Ltd | Professional & scientific | 2016 |
| MDL Smile Ltd | Health & social care | 2024 |
| Meadowcroft Management Company Limited | Households | 2005 |
| Meals on Point Ltd | Manufacturing | 2025 |
| Meinir Consulting Ltd | Professional & scientific | 2022 |
| Meraki Alliance Ltd | Professional & scientific | 2014 |
| Mermaid Seafoods Holdings Limited | Financial services | 2026 |
| Mermaid Seafoods Limited | Wholesale & retail | 2001 |
| Merrall-Ross International Limited | Extraterritorial | 1997 |
| METALPROO11 Limited | Wholesale & retail | 2025 |
| MI3 Limited | Manufacturing | 2006 |
| Michael Mcdonagh Painting & Decorating Contractors Limited | Construction | 2002 |
| Mind and Environment Counselling LLP | | 2023 |
| Minnie Bear Properties Limited | Real estate | 2025 |
| Mithra Renewables Limited | Professional & scientific | 2025 |
| MMK Media Ltd | Information & communication | 2018 |
| Mobiles 2026 Limited | Manufacturing | 2026 |
| Mocha House Ltd | Hospitality | 2019 |
| Mochdre Garage Limited | Wholesale & retail | 1937 |
| Modular Ceilings Limited | Manufacturing | 2008 |
| Moel Eilio 1969 Limited | Extraterritorial | 2014 |
| Molvin and Love Limited | Construction | 2024 |
| MON Builders Limited | Construction | 2015 |
| MON Developers Ltd | Construction | 2015 |
| Money Hunter Limited | Manufacturing | 2023 |
| Montclare Hotel Limited | Hospitality | 2021 |
| Monterey Apartments Management Company Limited | Households | 2006 |
| Moorcroft Residential Homes Limited | Real estate | 2004 |
| Morfa Garage Ltd | Wholesale & retail | 2012 |
| Morfa Group Ltd | Real estate | 2025 |
| Morgan Commercial Limited | Construction | 2024 |
| Morris Safety & Training Ltd. | Construction | 2020 |
| Mount Royal Rhos on Sea Limited | Real estate | 1994 |
| Mount Stewart Limited | Hospitality | 2001 |
| Multi Business Services Limited | Extraterritorial | 1991 |
| Multiply Academy Limited | Information & communication | 2005 |
| Mutiny Brewing Ltd | Manufacturing | 2021 |
| My Mentor Services Ltd | Administrative & support | 2025 |
| Mynnaf Translations Limited | Professional & scientific | 2012 |
| Myrepairuk Limited | Other services | 2023 |
| Mythos Rhos Ltd | Hospitality | 2026 |
| N Radcliffe Services Ltd | Transport & logistics | 2018 |
| N Stephens Business Group Limited | Professional & scientific | 2017 |
| N W Motors Ltd | Wholesale & retail | 2024 |
| N.W Surfacing Ltd | Construction | 2020 |
| Nametest Limited | Households | 1991 |
| Naomi Marshall Limited | Health & social care | 2013 |
| Narey Capital Limited | Financial services | 2014 |
| National Eviction Team Limited | Extraterritorial | 2015 |
| National Caravan Salvage Limited | Wholesale & retail | 2015 |
| National Zoological Society of Wales Ltd | Arts & recreation | 1983 |
| Nationwide Ambulance Academy Ltd | Education | 2022 |
| Nationwide Ambulance Group Ltd | Administrative & support | 2025 |
| Ncgrillerz Ltd | Hospitality | 2021 |
| NE1CONNECT Ltd | Information & communication | 2023 |
| Nemma Ltd | Extraterritorial | 2024 |
| Nesl Construction Ltd | Construction | 2023 |
| Network Electrical Wholesalers Limited | Wholesale & retail | 2000 |
| Network Home Rentals Limited | Real estate | 2016 |
| Network New Europe Limited | Professional & scientific | 2008 |
| Network Plus Limited | Information & communication | 2003 |
| Network Service Facilities Ltd | Professional & scientific | 2008 |
| NEV Bannisters Garages Limited | Real estate | 1946 |
| New Edition Limited | Wholesale & retail | 2005 |
| New Life Revival Church (Wales) | Other services | 2012 |
| Nexred Ltd | Wholesale & retail | 2024 |
| NHR Joinery (NW) Ltd | Administrative & support | 2017 |
| Nicolson's Plastering Ltd | Construction | 2025 |