| MGA Investments Ltd | Financial services | 2014 |
| MGD International Consulting Ltd | Professional & scientific | 2025 |
| MH Copy Limited | Professional & scientific | 2010 |
| MI Projects Limited | Other services | 2005 |
| Micah Limited | Extraterritorial | 2003 |
| Michael Binyon Limited | Information & communication | 2013 |
| Michael Kimuli & Associates Limited | Health & social care | 2018 |
| Middleton Capital Investments Ltd | Real estate | 2024 |
| Midland Yorkshire Ltd | Real estate | 2017 |
| Midwood Holdings Limited | Financial services | 2020 |
| Mighty Atoms Incorporated Limited | Administrative & support | 2023 |
| Mikumi Investments Ltd | Wholesale & retail | 2020 |
| Milanformilad Barbers Ltd | Other services | 2026 |
| Milestone Design Limited | Manufacturing | 2003 |
| Mimico Ltd | Wholesale & retail | 2018 |
| Mimu Property Limited | Real estate | 2011 |
| Mirador Development Services Limited | Real estate | 2013 |
| MJ Property Renovation & Building Services Ltd | Construction | 2015 |
| MJD Developments Ilkley Ltd | Construction | 2023 |
| MJD Property Funding Ltd | Administrative & support | 2017 |
| MJH Joinery & Fencing Ltd | Construction | 2026 |
| Mjweatherhead Ltd | Wholesale & retail | 2025 |
| Mldp Holdings Ltd | Real estate | 2025 |
| MLF Computer Services Limited | Administrative & support | 2025 |
| Mlrj Ltd | Real estate | 2025 |
| Mobile Expeditions Ltd | Administrative & support | 2026 |
| Moda Group Limited | Construction | 1987 |
| Modellr Limited | Professional & scientific | 2021 |
| Modern Project Services (NW) Limited | Administrative & support | 2011 |
| Modern Project Services (UK) Ltd | Administrative & support | 2018 |
| Modern Slavery Consultants Ltd | Professional & scientific | 2015 |
| Modular Holdings Group Ltd | Administrative & support | 2020 |
| Modus Onepay Limited | Financial services | 2017 |
| Modus UK Limited | Financial services | 2006 |
| Moghul Burley Ltd | Hospitality | 2022 |
| Mohun Aldridge Sykes Limited | Professional & scientific | 2010 |
| Mojo Barber Shop Ltd | Other services | 2015 |
| Mollie & Mauve Limited | Wholesale & retail | 2021 |
| Moneyglass Films Two Limited | Information & communication | 2015 |
| Monte Partners Ltd | Wholesale & retail | 2023 |
| Montenova Limited | Real estate | 2025 |
| Montgomery Homes (UK) Limited | Real estate | 2007 |
| Montpellier (Harrogate) Limited | Construction | 2014 |
| Moor Destinations Limited | Arts & recreation | 2006 |
| Moor Fruit & VEG Ltd | Wholesale & retail | 2025 |
| Moor Health Ltd | Health & social care | 2022 |
| Moor Leasing Limited | Financial services | 2003 |
| Moor Music Ltd | Information & communication | 2025 |
| Moor Park Management Limited | Households | 2001 |
| Moor Solar Limited | Professional & scientific | 2010 |
| Moorcloudservices Ltd | Information & communication | 2014 |
| Moorfield School Limited | Education | 1965 |
| Moorlands Learning Trust | Education | 2011 |
| Morgan Knight Consultants Ltd | Other services | 2019 |
| Morning Motivation Club Ltd | Other services | 2025 |
| Moss Agency Services Ltd | Construction | 2020 |
| Moss and Moor Limited | Wholesale & retail | 2019 |
| Motive Analytics Ltd | Information & communication | 2019 |
| Moulton Wealth Management Limited | Financial services | 2025 |
| Mounsey Marking Services Ltd | Education | 2022 |
| Mount Hooley Farm Management Company Limited | Water & waste | 2009 |
| Mountwarren Limited | Arts & recreation | 2009 |
| Mowgli Alexander Holdings Ltd | Real estate | 2025 |
| MR Bespoke Limited | Other services | 2026 |
| MR1 Studio Ltd | Professional & scientific | 2020 |
| MS Business Solution Services Limited | Administrative & support | 2010 |
| Msrs Properties Ltd | Real estate | 2024 |
| MST Projects Limited | Professional & scientific | 2010 |
| MTJ Properties Limited | Real estate | 2024 |
| MU Yorkshire Limited | Information & communication | 2011 |
| Muang Loei Thai Food Limited | Hospitality | 2025 |
| Multi-Task Cleaning Limited | Administrative & support | 2009 |
| Munners Limited | Professional & scientific | 2022 |
| Murfinron | Financial services | 2022 |
| Murley Scott Ltd | Real estate | 2018 |
| Murray Everlasting Properties Ltd | Real estate | 2025 |
| Myco Technologies Limited | Information & communication | 2017 |
| Myddelton Properties Limited | Real estate | 2020 |
| Myddleton Consulting Limited | Professional & scientific | 2014 |
| Myddleton Services Limited | Professional & scientific | 2018 |
| Mystic Glade Limited | Real estate | 2025 |
| Myth & Method Ltd | Wholesale & retail | 2025 |
| N H Joinery Ltd | Construction | 2009 |
| N Harrison Construction Ltd | Construction | 2022 |
| N.J. Phillips (Builders & Contractors) Ltd | Construction | 2003 |
| N.Winterbottom Ltd | Professional & scientific | 2024 |
| Naimaya and Associates Ltd | Real estate | 2025 |
| Nanu Soda Limited | Professional & scientific | 2011 |
| NAS Global Properties Ltd | Real estate | 2024 |
| NAT Vegas Ltd | Arts & recreation | 2011 |
| Nateworld Ltd | Information & communication | 2025 |
| Natural Solutions Yorkshire Ltd | Construction | 2024 |
| Naulty's Ltd | Real estate | 2026 |
| Nebstone Limited | Professional & scientific | 2003 |
| Needham Geoscience Limited | Mining & quarrying | 2007 |
| Needle & Fern Ltd | Wholesale & retail | 2026 |
| Negroni Breakfast Ltd | Professional & scientific | 2024 |
| Nell's Kitchen Limited | Hospitality | 2024 |
| Nellstar Rentals Ltd | Real estate | 2025 |
| Nelson Court (Ilkley) Ltd | Real estate | 2007 |