| Mornington Mews Management Company Limited | Households | 2004 |
| Morphets of Harrogate Limited | Wholesale & retail | 2011 |
| Morphr Ltd | Professional & scientific | 2021 |
| Morrell Physiotherapy Limited | Health & social care | 2016 |
| Morris Financial Planning Limited | Financial services | 2011 |
| Mortensen Limited | Extraterritorial | 2026 |
| Mortgage Solutions of Harrogate Ltd | Financial services | 2018 |
| Mosaic Partnership Wellbeing Limited | Professional & scientific | 2022 |
| Moss & Clucks Limited | Hospitality | 2018 |
| Moss Barns Management Company Limited | Households | 2020 |
| Moss Family Holdings Ltd | Professional & scientific | 2025 |
| Moss Grange Management Company Limited | Households | 2013 |
| Most Construction Limited | Construction | 1988 |
| Most Holdings Ltd | Construction | 2024 |
| Motionrehab Limited | Professional & scientific | 2017 |
| Motobarn Limited | Wholesale & retail | 2023 |
| Motorhomes 2YOU Limited | Wholesale & retail | 2016 |
| Motorhomes North Ltd | Wholesale & retail | 2020 |
| Motors 24/7 Ltd | Wholesale & retail | 2016 |
| Motortradex Limited | Wholesale & retail | 2008 |
| Motorvation of Harrogate Bodyshop & Repairs Limited | Wholesale & retail | 2024 |
| Motuu Limited | Financial services | 2020 |
| Moulthaven Management Company Ltd | Households | 2005 |
| Mountford Group Limited | Extraterritorial | 2026 |
| Moussaka Ltd | Extraterritorial | 2012 |
| MOV1E Ltd | Extraterritorial | 2020 |
| Move Consultancy Ltd | Education | 2025 |
| Move Physiotherapy Pilates Ltd | Arts & recreation | 2025 |
| MOVED2 Ltd | Wholesale & retail | 2021 |
| Movida Consulting Limited | Professional & scientific | 2026 |
| Mowbray Community Church | Other services | 2010 |
| Mowbray Mews Management (Harrogate) Limited | Households | 2005 |
| Mowbray Square Medical Limited | Health & social care | 2009 |
| Moxmoor Ltd | Hospitality | 2021 |
| MP Removals and Storage Ltd | Transport & logistics | 2025 |
| MPA Fire & Security Ltd | Administrative & support | 2025 |
| MPC Harrogate Design Ltd | Construction | 2012 |
| MPH Wealth Management Limited | Financial services | 2014 |
| MPP (Properties) Limited | Real estate | 2015 |
| MPR UK Limited | Wholesale & retail | 2008 |
| MPW Recovery Limited | Wholesale & retail | 2018 |
| MR Arkwright's Tool Emporium Limited | Wholesale & retail | 2014 |
| MR Compliance & Risk Services Limited | Professional & scientific | 2022 |
| MR Construction Management Ltd | Households | 2014 |
| MR Cropper Limited | Extraterritorial | 2000 |
| MR Drit Limited | Water & waste | 2025 |
| MR Farage Limited | Extraterritorial | 2015 |
| MR Landscape and Garden Maintenance Ltd | Administrative & support | 2019 |
| MR S1NGH Ltd | Extraterritorial | 2019 |
| MR Sauna Ltd | Health & social care | 2016 |
| MR Vegan Cakes Ltd | Manufacturing | 2019 |
| MR Xmas Ltd | Extraterritorial | 2012 |
| MRA Electrical & Security Limited | Professional & scientific | 2006 |
| MRH Plumbing & Heating Ltd | Construction | 2016 |
| MRS Energy Limited | Energy | 2016 |
| MRS Gfys Ltd. | Manufacturing | 2025 |
| MRS Power Limited | Energy | 2013 |
| MRS Ritchie Ltd. | Manufacturing | 2013 |
| MRS Stone Store Limited | Professional & scientific | 2011 |
| MS Developments (Salford) Ltd | Construction | 2021 |
| MTJ Plumbing Services Limited | Construction | 2023 |
| Mtroniks Limited | Manufacturing | 1993 |
| Mts-Art Ltd | Manufacturing | 2011 |
| MTX Trader LAB Ltd | Information & communication | 2019 |
| MU5IC Limited | Extraterritorial | 2017 |
| MUD and Puddles Limited | Education | 2018 |
| Mulan Door Food and Drink Ltd | Wholesale & retail | 2021 |
| Muller Group Limited | Extraterritorial | 2025 |
| Multi Operator Self Exclusion Scheme Ltd | Administrative & support | 2016 |
| Mumbler Ltd | Other services | 2014 |
| Mummy Ltd | Extraterritorial | 2012 |
| Munch Mania Ltd | Hospitality | 2024 |
| Munchkin UK Trading Company Ltd | Extraterritorial | 2009 |
| Mung International Ltd | Administrative & support | 2025 |
| Munje International Ltd | Construction | 2021 |
| Munro Connections Ltd | Professional & scientific | 2006 |
| Munro Ogilvie Limited | Financial services | 2020 |
| Murcia Golf Properties Limited | Real estate | 2006 |
| Murmuration Ltd | Hospitality | 2016 |
| Murphy Acquisitions Limited | Real estate | 2020 |
| Murwell Consulting Engineers Limited | Administrative & support | 2003 |
| Musitude Limited | Information & communication | 2014 |
| Muskaan Beauty Ltd | Other services | 2012 |
| Mustaqeem Services for Trade Ltd | Hospitality | 2025 |
| Mutherboard.Com Ltd | Professional & scientific | 2021 |
| Muzo Works Limited | Manufacturing | 2014 |
| MV Plumbing and Heating (Harrogate) Ltd | Construction | 2016 |
| MVH Harrogate Limited | Professional & scientific | 2018 |
| MW Accounting Solutions Ltd | Professional & scientific | 2019 |
| MW Accounting Walker Limited | Professional & scientific | 2022 |
| MW Marketing Solutions Ltd | Transport & logistics | 2013 |
| MWB Trading Ltd | Wholesale & retail | 2019 |
| MWK Locums Ltd | Health & social care | 2024 |
| My Chefs Direct Ltd | Hospitality | 2018 |
| My Chien & Co Limited | Wholesale & retail | 2022 |
| My Company Secretary Limited | Administrative & support | 2016 |
| My Compliance Consultant Limited | Professional & scientific | 2020 |
| My Digital Hero Consulting Limited | Professional & scientific | 2018 |
| My Medical Cover Ltd | Financial services | 2021 |
| My Possible Self Limited | Administrative & support | 2009 |