| Lysi Builders Limited | Construction | 2005 |
| M & a Medics Ltd | Health & social care | 2021 |
| M & B Properties SV Ltd | Real estate | 2013 |
| M & K Halal Meat & Poultry Ltd | Wholesale & retail | 2016 |
| M & R General Services Ltd. | Construction | 2019 |
| M Akinwale Ltd | Real estate | 2025 |
| M Bobeica Building Services Ltd | Construction | 2019 |
| M Building Construction Ltd | Construction | 2020 |
| M Coisy Home Care Service Ltd | Wholesale & retail | 2020 |
| M Corporate Ltd | Financial services | 2021 |
| M D Robin Limited | Real estate | 2024 |
| M G P Contractors Ltd | Construction | 2025 |
| M GEE Investments Limited | Real estate | 2016 |
| M H 14 Ltd | Information & communication | 2025 |
| M I B United Meat Limited | Wholesale & retail | 2005 |
| M K Afriyie Interiors Ltd | Construction | 2025 |
| M Kumaran Ltd | Wholesale & retail | 2021 |
| M Marine Limited | Professional & scientific | 2016 |
| M P Build Ltd | Construction | 2019 |
| M&A Maidenhead Limited | Other services | 2023 |
| M&B Legal Ltd | Professional & scientific | 2021 |
| M&H Fleet Hire Ltd | Administrative & support | 2021 |
| M&H Investment Properties Ltd | Real estate | 2025 |
| M&K Enterprise Holdings Ltd | Professional & scientific | 2017 |
| M&K Zaman Consultancy Services Ltd | Administrative & support | 2026 |
| M&L Plumbing and Heating (UK) Ltd | Construction | 2013 |
| M&M International Consulting Ltd | Professional & scientific | 2014 |
| M&M Quality Used Cars Ltd | Wholesale & retail | 2026 |
| M&S BBQ Ltd | Hospitality | 2021 |
| M-Sparks Limited | Construction | 2007 |
| M.A Snack Bar Limited | Wholesale & retail | 2015 |
| M.C. Express Ltd | Transport & logistics | 2017 |
| M.D Estates (South East) Limited | Real estate | 2005 |
| M.H.J. Crausaz Limited | Health & social care | 1979 |
| M.J.L Technical Services Ltd | Construction | 2022 |
| M.M. MNL Limited | Construction | 2020 |
| M.O Postal Services Ltd | Transport & logistics | 2026 |
| M.O.K. Internet Cafe Ltd | Manufacturing | 2026 |
| M.R. Windows Doors Ltd | Wholesale & retail | 2022 |
| M.R. Windows Limited | Construction | 2007 |
| M/S Mittar Paul International Ltd | Wholesale & retail | 2024 |
| M4K3R Ltd | Manufacturing | 2025 |
| MA Cherie Entertainment Ltd | Arts & recreation | 2024 |
| MA Distro Ltd | Administrative & support | 2025 |
| MA Horizon Ventures Ltd | Real estate | 2026 |
| Ma&K Development Ltd | Construction | 2022 |
| Ma&Lg Property Ltd | Real estate | 2024 |
| MAA Management Ltd | Real estate | 2025 |
| Maamey’S Agape Kitchen Ltd | Hospitality | 2022 |
| Maathru Properties Ltd | Real estate | 2019 |
| Maathru Technologies Ltd | Professional & scientific | 2012 |
| Maathru Trading Ltd | Information & communication | 2019 |
| MAB Love Care Limited | Health & social care | 2024 |
| Maba Construction Ltd | Construction | 2024 |
| Mabast Limited | Wholesale & retail | 2023 |
| Mabete Chilcare Ltd | Health & social care | 2022 |
| MAC Bookkeeping Ltd | Wholesale & retail | 2020 |
| MAC Professional Haircare Limited | Manufacturing | 2008 |
| MAC Sure Standard Ltd | Administrative & support | 2018 |
| MAC Transport Solutions Ltd | Transport & logistics | 2018 |
| Macaroni Housing Limited | Real estate | 2021 |
| Maccarthy Contractors Ltd | Construction | 2020 |
| Machic Property Services UK Ltd | Hospitality | 2025 |
| Maciej Kranc Ltd | Transport & logistics | 2018 |
| Macoku Brothers Ltd | Manufacturing | 2025 |
| Mactrad Ltd | Real estate | 2024 |
| MAD Dogs & Ltd | Professional & scientific | 2015 |
| Madame BE Limited | Wholesale & retail | 2025 |
| Made to Send Limited | Wholesale & retail | 2018 |
| MADEAT94 Ltd | Arts & recreation | 2008 |
| Madigs Dwellings Limited | Real estate | 2021 |
| MAE Accountancy Services Ltd | Professional & scientific | 2025 |
| Maestro Accountancy Support Solutions Limited | Professional & scientific | 2024 |
| Maestro Global Ltd | Wholesale & retail | 2024 |
| Maestro Milli Ltd | Information & communication | 2023 |
| Maestro Support Solutions Limited | Administrative & support | 2020 |
| Mafet Consultancy Limited | Other services | 2024 |
| Magbull Limited | Professional & scientific | 2015 |
| Mage Properties Ltd | Real estate | 2020 |
| Magentar Healthcare Services Ltd | Administrative & support | 2022 |
| Magentis Solutions Ltd | Information & communication | 2019 |
| Magestore Ltd | Wholesale & retail | 2025 |
| Maghoma Hospitality Group Ltd | Financial services | 2025 |
| Maghull Industrial Land Limited | Financial services | 2026 |
| Magic Corn Edmonton Green Ltd | Hospitality | 2024 |
| Magic Hands Painting & Decorating Ltd | Construction | 2022 |
| Magic Madhouse Limited | Wholesale & retail | 2012 |
| Magic Scaffolding Ltd | Construction | 2013 |
| Magna Clinical Services Limited | Professional & scientific | 2021 |
| Magpie Electrical Compliance Ltd | Professional & scientific | 2019 |
| Magpie on the Run Ltd | Wholesale & retail | 2013 |
| Magrun Ltd | Construction | 2008 |
| Maguire Construction Services Limited | Professional & scientific | 2022 |
| Mahdi Property Investments Limited | Real estate | 2021 |
| Mahia Limited | Professional & scientific | 2020 |
| Mahir Invst Ltd | Real estate | 2025 |
| Mains Electrical Engineering Ltd | Construction | 2022 |
| Maintenance Direct Solutions Ltd | Construction | 2025 |
| Maintenance UK Service Limited | Construction | 2025 |
| Maintenanceqr Ltd | Information & communication | 2025 |