| M&A Takeaway Ltd | Hospitality | 2026 |
| M&Ba Properties Ltd | Real estate | 2021 |
| M&C Property Group Ltd | Real estate | 2025 |
| M&D Building Maintenance SVS Ltd | Construction | 2011 |
| M&D Digital Ltd | Information & communication | 2020 |
| M&D Investments 25 Limited | Real estate | 2025 |
| M&D Store Ltd | Wholesale & retail | 2025 |
| M&E UK Holdings Ltd | Financial services | 2021 |
| M&F Development(Leeds) Ltd | Construction | 2020 |
| M&H Convenience Store Ltd | Wholesale & retail | 2023 |
| M&H Reliance Ltd | Wholesale & retail | 2026 |
| M&I Group Ltd | Wholesale & retail | 2025 |
| M&J Coatings Saloutions Ltd | Construction | 2025 |
| M&J Data Consulting Ltd | Information & communication | 2025 |
| M&J Hoofcare Ltd | Agriculture & fishing | 2018 |
| M&J Lovett Ltd | Professional & scientific | 2022 |
| M&J Vending Ltd | Wholesale & retail | 2025 |
| M&Lg Investments | Other services | 2020 |
| M&M Car Sales and Rent Ltd | Wholesale & retail | 2026 |
| M&M Future Homes Ltd | Real estate | 2024 |
| M&M Knowles Limited | Hospitality | 2020 |
| M&M Public Houses Ltd | Hospitality | 2023 |
| M&M Residential Ltd | Real estate | 2025 |
| M&M Seasons Ltd | Hospitality | 2022 |
| M&R Pharma Care Ltd | Health & social care | 2022 |
| M&S Moving Solutions Ltd | Transport & logistics | 2025 |
| M&S Private Equity Limited | Real estate | 2019 |
| M&S Properties Enfield Ltd | Real estate | 2025 |
| M&V Professional Garden Cleaning Services Ltd | Arts & recreation | 2025 |
| M&Z AM Limited | Real estate | 2026 |
| M'Deena Ltd | Hospitality | 2014 |
| M-Jay Electronics Limited | Manufacturing | 1977 |
| M-Phases Limited | Professional & scientific | 2023 |
| M-Powered People and Communities CIC | Administrative & support | 2026 |
| M. & E. Cornell Limited, | Real estate | 1963 |
| M. B. Locking Logistics Group Limited | Administrative & support | 1992 |
| M. Eccles Limited | Professional & scientific | 2009 |
| M. Gannon (C.A.D.) Design Services Limited | Construction | 1999 |
| M. Mynett Draughting Services Limited | Professional & scientific | 1995 |
| M. Stoker Electrical Ltd | Construction | 2014 |
| M. Support Services Ltd | Administrative & support | 2019 |
| M.A Locum Limited | Health & social care | 2019 |
| M.A.C. Residentials Limited | Real estate | 2025 |
| M.A.G. Driver Services Ltd | Transport & logistics | 2025 |
| M.Aj-Traders Ltd | Wholesale & retail | 2021 |
| M.B. Access Control Limited | Extraterritorial | 1996 |
| M.D. Paving (Yorkshire) Ltd. | Administrative & support | 2016 |
| M.E.Q Mining Ltd | Construction | 2024 |
| M.E.T.L. Limited | Professional & scientific | 2006 |
| M.G Nexus Ltd | Real estate | 2026 |
| M.G.Heating & Ventilation Limited | Manufacturing | 2013 |
| M.H. Bradd Limited | Construction | 1990 |
| M.I. Graham Limited | Construction | 2003 |
| M.I.A.Q Advocacy Ltd | Professional & scientific | 2026 |
| M.J. Brookes Enterprises Limited | Real estate | 2019 |
| M.J. Mccarthy Limited | Financial services | 2016 |
| M.J.Uph Leeds Ltd | Administrative & support | 2012 |
| M.Jay. Consultants Ltd | Professional & scientific | 2025 |
| M.L Joinery Limited | Manufacturing | 2024 |
| M.L.Collins,Limited | Extraterritorial | 1946 |
| M.N.G.M Limited | Professional & scientific | 2018 |
| M.P.M.J. Developments Limited | Construction | 2021 |
| M.R.E Asset Holdings Limited | Financial services | 2026 |
| M.R.E. Plant and Groundworks Ltd | Construction | 2018 |
| M.R.S Mobile Rubber Solutions Ltd | Wholesale & retail | 2019 |
| M.R.S Transport Ltd | Transport & logistics | 2025 |
| M.R.S. Properties Limited | Construction | 1986 |
| M.R.V Plumbing and Heating Limited | Construction | 2021 |
| M.S Properties (Yorkshire) Limited | Real estate | 2022 |
| M.Sedgwick & Company Limited | Manufacturing | 1957 |
| M.T.R. Contractors Limited | Construction | 1993 |
| M.W.R Electrical Ltd | Construction | 2015 |
| M1 Commercials Ltd | Wholesale & retail | 2024 |
| M1 Living Limited | Extraterritorial | 2021 |
| M2 Design & Planning Limited | Construction | 2016 |
| M26 Solution Ltd | Administrative & support | 2026 |
| M2M Consulting Ltd | Information & communication | 2018 |
| M3 Apparel Ltd | Wholesale & retail | 2025 |
| M3 Builders Ltd | Construction | 2018 |
| M3 Developments (Leeds) Limited | Construction | 2013 |
| M3 Groundworks Ltd | Construction | 2015 |
| M4 Civil Engineering Limited | Professional & scientific | 2022 |
| M44 Investments Ltd | Real estate | 2023 |
| M4L Holdings Limited | Financial services | 2020 |
| M62 Advertising Limited | Professional & scientific | 2008 |
| M62 Services Limited | Wholesale & retail | 2015 |
| M62EXPRESS Limited | Transport & logistics | 2026 |
| M7 Courier & Logistics Service Ltd | Transport & logistics | 2024 |
| M8TAG Limited | Information & communication | 2018 |
| MA & LA Otley Ltd | Arts & recreation | 2016 |
| MA & SZ PVT Ltd | Wholesale & retail | 2021 |
| MA Holdings Ltd | Real estate | 2021 |
| MA Houses (Yorkshire) Ltd | Real estate | 2025 |
| MA One Global Ltd | Wholesale & retail | 2026 |
| MA Restaurant Leeds Ltd | Hospitality | 2019 |
| MA Security Limited | Administrative & support | 2015 |
| MA Urological Services Ltd | Health & social care | 2024 |
| MA Vehicle Solutions Ltd | Wholesale & retail | 2022 |
| Ma-Cn Limited | Health & social care | 2024 |
| Ma-Hé Coastal Indian Holdings Ltd | Hospitality | 2023 |