| Mill Cross (Pevensey) Management Company Limited | Households | 2024 |
| Mill Gardens (Cullompton) Management Company Limited | Households | 2022 |
| Mill Garth Court Limited | Households | 1984 |
| Mill Green Gardens (Penwortham) Management Company Limited | Households | 2025 |
| Mill Mount Management Limited | Households | 2010 |
| Mill Pastures Ltd | Arts & recreation | 2013 |
| Mill View (Willingdon) Management Company Limited | Administrative & support | 1995 |
| Milla Beauty Ltd | Other services | 2020 |
| Millbeck Grange (Bowburn) Management Company Limited | Households | 2019 |
| Millbrook Services Ltd | Transport & logistics | 2021 |
| Millea Group Ltd | Professional & scientific | 2019 |
| Millea Land (Epworth) Ltd | Professional & scientific | 2021 |
| Millenium Food & Wine Ltd | Wholesale & retail | 2013 |
| Millennium Farm (New Waltham) Management Company Limited | Households | 2018 |
| Miller & Gray Limited | Real estate | 2026 |
| Miller Reconstruction Ltd | Professional & scientific | 2008 |
| Millers Joinery Ltd | Construction | 2024 |
| Millers Street Food Ltd | Hospitality | 2022 |
| Millers Yard CIC | Professional & scientific | 2011 |
| Millfarm Holidays Limited | Hospitality | 2020 |
| Millfarm Properties Limited | Hospitality | 2020 |
| Millfield Lane (York) Management Company Limited | Households | 2007 |
| Millfield Lane Owners Club Limited | Households | 2019 |
| Millfield Properties Wheldrake Ltd | Real estate | 2024 |
| Millfield Signalling Limited | Professional & scientific | 2020 |
| Milliefox Kitchen Ltd | Hospitality | 2023 |
| Millies (Leeds) Ltd | Wholesale & retail | 2014 |
| Millies Holding Company Ltd | Financial services | 2026 |
| Millifam Holdings Limited | Financial services | 2025 |
| Milligan Law Limited | Professional & scientific | 2013 |
| Millstone Development Limited | Construction | 2024 |
| Milly Mason Ltd | Other services | 2022 |
| Milly's Beauty Bar Ltd | Other services | 2022 |
| Milner Black Associates Limited | Professional & scientific | 2014 |
| Milner Court Limited | Hospitality | 2006 |
| Milner Holdings (York) Limited | Financial services | 2018 |
| Milner Holdings Limited | Wholesale & retail | 2002 |
| Milner Homes (York) Limited | Construction | 2009 |
| Milner Offshore Ltd | Mining & quarrying | 2015 |
| Milner Property Group Ltd | Construction | 2023 |
| Milthorp International Limited | Extraterritorial | 2000 |
| Milton Bidco Limited | Financial services | 2026 |
| Milton Keynes Housing Group Limited | Extraterritorial | 1989 |
| Milton Midco Limited | Financial services | 2026 |
| Milton Topco Limited | Financial services | 2026 |
| Mimetic Laboratories Limited | Professional & scientific | 2018 |
| Mimi Mentoring&Development Business Limited | Professional & scientific | 2022 |
| Mimosa Star Limited | Financial services | 2018 |
| Mimram Veterinary Centre Limited | Extraterritorial | 2011 |
| Mina Shop Ltd | Hospitality | 2024 |
| Mind HOW YOU Go Limited | Professional & scientific | 2013 |
| Mind Matters Counselling LLP | | 2002 |
| Mind Safari Limited | Education | 2025 |
| Mind YER Website Ltd | Professional & scientific | 2017 |
| Minden Consult Ltd | Professional & scientific | 2022 |
| Mindful Chef Topco Limited | Financial services | 2020 |
| Mindful Memorials Limited | Manufacturing | 2022 |
| Mindful Photography UK CIC | Professional & scientific | 2022 |
| Mindshare Leadership Ltd | Professional & scientific | 2025 |
| Mindskills Training Limited | Professional & scientific | 2007 |
| Mindue Homes Limited | Real estate | 2021 |
| Mineral Mine Limited | Wholesale & retail | 2025 |
| Minerva Appliances Ltd | Wholesale & retail | 2019 |
| Minerva Parts Ltd | Wholesale & retail | 2023 |
| Minerva Rental Limited | Hospitality | 2021 |
| Minerva Solutions and Consultancy Ltd | Information & communication | 2021 |
| Minford Holdings Limited | Professional & scientific | 2016 |
| Mini Swimmers Ltd | Education | 2011 |
| Minifigs & Bricks Limited | Wholesale & retail | 2013 |
| Minor Details Limited | Wholesale & retail | 2024 |
| Minskip Garage Limited | Wholesale & retail | 2003 |
| Minster - York Business Hub Ltd | Real estate | 2020 |
| Minster Alarms Ltd | Construction | 2007 |
| Minster Auto Repairs Limited | Wholesale & retail | 2024 |
| Minster Baywatch Ltd | Administrative & support | 2011 |
| Minster Brickwork Limited | Construction | 2025 |
| Minster Building Services (York) Ltd | Extraterritorial | 2011 |
| Minster Dents Limited | Wholesale & retail | 2015 |
| Minster Developments York Limited | Construction | 2026 |
| Minster Electrical Limited | Professional & scientific | 2003 |
| Minster Energies Ltd | Extraterritorial | 2011 |
| Minster Energy Ltd | Extraterritorial | 2011 |
| Minster Energy Solutions Ltd | Extraterritorial | 2011 |
| Minster Environmental Solutions Ltd | Extraterritorial | 2011 |
| Minster Estates (York) Limited | Real estate | 2026 |
| Minster Fabrications Limited | Extraterritorial | 2003 |
| Minster Financial Planning Ltd | Professional & scientific | 2019 |
| Minster Green Limited | Real estate | 2014 |
| Minster Groundworks Limited | Administrative & support | 2012 |
| Minster Group Holdings Limited | Financial services | 2020 |
| Minster Home Care Ltd | Health & social care | 2020 |
| Minster HR Solutions Limited | Administrative & support | 2019 |
| Minster Leasing Limited | Administrative & support | 1995 |
| Minster Northfleet Limited | Wholesale & retail | 2016 |
| Minster Plumbing & Heating Limited | Construction | 1978 |
| Minster Powers Ltd | Extraterritorial | 2025 |
| Minster Property Lettings LLP | | 2006 |
| Minster Property Maintenance Limited | Administrative & support | 2013 |
| Minster Property Services (York) Ltd | Extraterritorial | 2011 |
| Minster Psychology Ltd | Health & social care | 2025 |