| Lotus Lampshades NW Ltd | Manufacturing | 2023 |
| Louis Llandudno Ltd | Hospitality | 2026 |
| LR Medical Limited | Health & social care | 2026 |
| Luciano Occhiali Ltd | Wholesale & retail | 2022 |
| Lucky House Gwynedd Limited | Hospitality | 2019 |
| Lucror Consulting Ltd | Professional & scientific | 2013 |
| Lucy's Mechanical Centre Ltd | Wholesale & retail | 2018 |
| Luigi Lettings Ltd | Extraterritorial | 2014 |
| Luma Interior Design Limited | Other services | 2025 |
| Lwind Ltd | Construction | 2025 |
| Lynton House Ltd | Hospitality | 2011 |
| M & R Construction (North Wales) Ltd | Construction | 2024 |
| M and N Lettings Ltd | Real estate | 2020 |
| M Beck Site Services Limited | Construction | 2021 |
| M E Contractors Limited | Construction | 2012 |
| M&M Beverages & Catering Ltd | Hospitality | 2015 |
| M&M Fire (Horley) Limited | Professional & scientific | 2022 |
| M. S. I. Alarms Limited | Administrative & support | 1986 |
| M.J. Economics Limited | Professional & scientific | 1998 |
| M.R.C.Searle Limited | Real estate | 1961 |
| Maddison Leigh Properties Ltd | Real estate | 2018 |
| Madoc Dental Care Limited | Health & social care | 2015 |
| Maesdu Golf Club Limited | Arts & recreation | 2014 |
| Mainframe Llandudno Ltd | Wholesale & retail | 2014 |
| Malam Court Management Company Ltd. | Households | 1991 |
| Manageup Ltd | Information & communication | 2021 |
| Mandarin Gifts Co. Ltd. | Wholesale & retail | 2009 |
| Manmoel LLP | | 2017 |
| Manor Hotel Llandudno Ltd | Hospitality | 2023 |
| Manor Park (Llandudno) Management Limited | Households | 2001 |
| Marine Surveys Limited | Transport & logistics | 2006 |
| Mark Butterworth Limited | Professional & scientific | 2002 |
| Marl Electronics Limited | Information & communication | 2002 |
| Martin Wind Ltd | Construction | 2025 |
| Mayfield Data Services Ltd | Information & communication | 2021 |
| MB Property (NW) Limited | Real estate | 2022 |
| Mcallister Leisure Limited | Arts & recreation | 2012 |
| Mckenzie Joinery Ltd | Construction | 2017 |
| MD CAD Services Ltd | Professional & scientific | 2018 |
| Meat on the Corner Limited | Wholesale & retail | 2009 |
| Memoz Chippy Ltd | Hospitality | 2024 |
| Menai Heating Limited | Construction | 2012 |
| Menai Renewables Limited | Construction | 2021 |
| Menz Barbers Ltd | Other services | 2014 |
| Mermaid Centre for Circus Arts Ltd | Education | 2020 |
| Merrion Hotel Limited | Hospitality | 1959 |
| Merrydale Llandudno Ltd | Administrative & support | 2018 |
| Mhel Ltd | Health & social care | 2022 |
| Mike Dowle Ltd | Manufacturing | 2019 |
| Mileline Property Management Company Limited | Households | 1991 |
| Miller Electrical (North West) Ltd | Construction | 2019 |
| MIN Y DON Kitchen Ltd | Extraterritorial | 2021 |
| Mindful Directory Ltd | Information & communication | 2018 |
| Minifigure ME Ltd | Other services | 2018 |
| MJ & SP Boughen Limited | Hospitality | 2003 |
| MJK Fire Ltd | Administrative & support | 2023 |
| MM Pizza Braunton Ltd | Hospitality | 2020 |
| Mmsh Solutions Ltd | Professional & scientific | 2019 |
| Mobilia Repairs Ltd | Other services | 2015 |
| Montgomery Property Services Ltd | Construction | 2024 |
| Montrose Management Limited | Hospitality | 2004 |
| Moorcroft Residential Care Home Limited | Health & social care | 2022 |
| Moore Car Sales Limited | Wholesale & retail | 2014 |
| Moore-Me Ltd | Health & social care | 2023 |
| Morfa North Ltd | Construction | 2026 |
| Morgan Fire & Training Solutions Ltd | Professional & scientific | 2026 |
| Morland Wealth Management Ltd | Professional & scientific | 2020 |
| Morris Composites Limited | Manufacturing | 2014 |
| Mostyn Estates Limited | Real estate | 1925 |
| Mostyn Street ALE House Ltd | Hospitality | 2026 |
| Motion Blur Limited | Information & communication | 2003 |
| Mount Olives Management Company Limited | Real estate | 1990 |
| MR Fix-It (North Wales) Ltd | Construction | 2012 |
| MSJ Projects NW Ltd | Construction | 2025 |
| Msputtu Ltd | Wholesale & retail | 2021 |
| Mtsa Limited | Wholesale & retail | 2023 |
| Muhan Ltd | Health & social care | 2011 |
| Mulberry Guest House Limited | Hospitality | 2021 |
| Murphy Vets Limited | Professional & scientific | 2025 |
| Murshi London Ltd | Wholesale & retail | 2019 |
| MW Contracting (NW) Limited | Construction | 2018 |
| MW Contracting Ltd | Construction | 2022 |
| Mynegi LLP | | 2023 |
| Myrddin Innovations Ltd | Professional & scientific | 2025 |
| N & J Developments Limited | Construction | 2006 |
| N W Party Wall Surveyors Ltd | Professional & scientific | 2023 |
| N.W.K. Limited | Information & communication | 1997 |
| Naam Groups Ltd | Wholesale & retail | 2025 |
| Nant Y Glyn Ltd | Other services | 2021 |
| Nantwich & Border Counties Yacht Club Limited | Other services | 1973 |
| Natural Health Support Ltd | Health & social care | 2024 |
| Ndistribution Limited | Wholesale & retail | 2012 |
| Nelson Leisure Limited | Administrative & support | 2004 |
| New Heights Firewood Ltd | Agriculture & fishing | 2014 |
| New Loretta Hotel Limited | Hospitality | 1994 |
| New Vision Languages Limited | Professional & scientific | 2018 |
| Nick Elphick Ltd | Arts & recreation | 2018 |
| Nigel Dudley Construction Ltd | Construction | 2016 |
| Nitishali Productions UK Ltd | Information & communication | 2026 |
| NJ & Sons Properties Ltd | Real estate | 2018 |